Bulletin of the British Museum (Natural History). British Museum (Natural History) Converted as part of the ABLE project by Dauvit King London : BM(NH) Set of bird parts only held at TOS 112. General Library missing Vol 55-56, 1989-90 Vol.1 (1950)- 4 5 6 This document has been converted to TEI XML as part of the ABLE project to make it more widely available to biodiversity researchers in a useful format. eng text No corrections have been made in the text. The original source has not been regularized or normalized. Quotation marks have not been processed. They are as in the original DjVu XML document. Hyphens, including end-of-line hyphens, have not been processed. They are as in the original DjVu XML document. The text has been segmented based purely on layout based on page breaks. No language level segmetation, such as sentences, tone-units or graphemic, has been applied. Additional mark up using taXMLit has been applied to the TEI XML based on analysis of the original source through the uBio and OpenCalais web services. (Add comment for fuzzy matching once this has been brought into the final workflow too.) Bulletin of the y ^ British Museum (Natural History) Zoology series Vol 35 1979 British Museum (Natural History)London 1979 Dates of publication of the parts No 1 26 April 1979 No 2 26 April 1979 No 3 26 April 1979 No 4 31 May 1979 No 5 28 June 1979 ISSN 0007-1498 Printed in Great Britain by Henry Ling Ltd, at the Dorset Press, Dorchester, Dorset ContentsZoology Volume 35 Page No 1 A revision of the 'acaecate' earthworms of the Pheretima group(Megascolecidae : Oligochaeta) : Archipheretima, Metapheretima,Planapheretima, Pleionogaster and Polypheretima. E. G. Easton 1 No 2 Miscellanea The dargyrome of the genus Euplotes (Hypotrichida, Ciliophora). M. A. Gates & C. R. Curds 127 A redescription of types of six species of Neotropical Veronicellidae(Mollusca; Gastropoda) in the British Museum (Natural History). J. W. Thome 135 A taxonomic study of six species of Upogebia Leach (Crustacea,Decapoda, Thalassinidea) in the collections of the British Museum(Natural History), London. N. Ngoc-Ho 147 Larval development of British prawns and shrimps (Crustacea:Decapoda: Natantia) 2. Palaemonetes (Palaemonetes) varians (Leach1814) and morphological variation. A. A. Fincham .......... 163 A revision of the spider genus Brettus (Araneae: Salticidae). F. R. Wanless 183 Notes on the osteology of the Arab horse with reference to a skeletoncollected in Egypt by Sir Flanders Petrie. J. Glutton-Brock & R. Burleigh 191 No 3 The planktonic copepods of the northeastern Atlantic Ocean: Harpacti-coida, Siphonostomatoida and Mormonilloida. G. A. Boxshall 201 No 4 Towards a phyletic classification of the 'genus' Haplochromis (Pisces,Cichlidae) and related taxa. Part I.P. H. Greenwood 265 No 5 A revision of the British species of the genus Phthiracarus Perty,1841 (Cryptostigmata : Euptyctima). B. W. Parry 323 Bulletin of the British Museum (Natural History) A revision of the 'acaecate' earthwormsof the Pheretima group (Megascolecidae:Oligochaeta): Archipheretima,Metapheretima, Planapheretima,Pleionogaster and Polypheretima. E. G. Easton Zoology series Vol 35 No 1 26 April 1979 The Bulletin of the British Museum (Natural History), instituted in 1949, is issued in fourscientific series, Botany, Entomology, Geology (incorporating Mineralogy) and Zoology, andan Historical series. Parts are published at irregular intervals as they become ready. Volumes will contain aboutthree hundred pages, and will not necessarily be completed within one calendar year. Subscription orders and enquiries about back issues should be sent to: Publications Sales,British Museum (Natural History), Cromwell Road, London SW7 5BD, England. World List abbreviation: Bull. Br. Mus. nat. Hist. (Zool.) Trustees of the British Museum (Natural History), 1979 ISSN 0007-1498 Zoology series Vol 35 No 1 pp 1-126British Museum (Natural History)Cromwell RoadLondon SW7 5BD Issued 26 April 1979 QfcNfcKJU. 4 NAY 1979 A revision of the 'acaecate' earthworms of thePheretima group (Megascolecidae: Oligochaeta):Archipheretima, Metapheretima, Planapheretima,Pleionogaster and Polypheretima E. G. Easton K Department of Zoology, British Museum (Natural History), Cromwell Road, London SW7 5BD Contents Synopsis 1 Introduction ............. 1 Morphology ............. 2 Numerical studies ............ 9 Distribution 13 Classification 17 Taxonomy ............. 20 Genus Archipheretima Michaelsen, 1928 ........ 21 Genus Polypheretima Michaelsen, 1934 28 Genus Planapheretima Michaelsen, 1934 ........ 64 Genus Metapheretima Michaelsen, 1928 78 Genus Pleionogaster Michaelsen, 1892 114 Species incertae sedis . . . . . . . . . . .116 Species transferred to 'caecate' Pheretimoid genera 119 Acknowledgements . . . . . . . . . . . .120 References 120 Index to specific and subspecific names . . . . . . . .124 Synopsis Following the studies on the Pheretima group of Asio-Australasian earthworms by Sims & Easton (1972),those genera lacking intestinal caeca, Archipheretima, Metapheretima (inc. Ephemitra), Planapheretima,Pleionogaster and Polypheretima, are examined by taximetric procedures. One hundred and fourteennominal species and subspecies are reviewed ; 75 species are regarded as valid and a further 25 are describedas new. Keys, descriptions and distributions are provided to the genera and species. The morphologicaldevelopment and structural specializations of the male pores are detailed and their taxonomic importanceis discussed. The nephridial systems of several species are described and doubt is expressed about thevalidity of attributing classificatory significance to these characters. The distribution of the Pheretimagroup of genera is established in the context of plate tectonics and the restrictions are correlated withpresent day climatic factors. Introduction Sims & Easton (1972) employed numerical techniques to detect phenetic assemblages within thegenus Pheretima auct. which at that time included 746 nominal species. From their studies on asample of 114 species, they concluded that eight genera should be recognized. Four, Archiphere-tima Michaelsen, 1928, Ephemitra Sims & Easton, 1972, Metapheretima Michaelsen, 1928 andPlanapheretima Michaelsen, 1934, contained species lacking intestinal caeca and the remainingfour, Amynthas Kinberg, 1867, Metaphire Sims & Easton, 1972, Pheretima Kinberg, 1867(sensu Sims & Easton, 1972) and Pithemera Sims & Easton, 1972, accommodated species withcaeca on the intestine. The authors assigned the nominal species previously included in Pheretima Bull. Br. Mus. nat. Hist. (Zool.) 35 (1): 1-126 Issued 26 April, 1979 2 E. G. E ASTON auct. to species-groups within these genera although they did not attempt to describe or taxono-mically revise the individual species. This report is a continuation of those taximetric studies and contains the results of criticalappraisals of all the taxa included in the 'acaecate' genera (Archipheretima, Ephemitra, Meta-pheretima and Planapheretimd) also the closely allied monotypic genus Pleionogaster Michaelsen,1892. After full investigation, the genus Metapheretima is now redefined to include Ephemitraand some of its species are assigned to Polypheretima Michaelsen, 1934, previously a synonym.Numerical procedures similar to those employed by Sims & Easton (1972) were adopted to testthe phenetic validities of the genera and to detect infra-generic groups. Descriptions, synonomiesand distributions are given of 100 valid species which are recognized among the five generainvestigated. The higher systematics and zoogeography of the acaecate genera are briefly discussed. 1m Fig. 1 Planapheretima hasselti, transverse section of body. Im, longitudinal muscle;km, circular muscle; hy, epidermis; cu, cuticle. (From Horst, 1883.) Morphology An account of the morphological features observed to vary among the species of the Pheretimagroup of genera and found to be useful for delineating taxa was provided by Sims & Easton(1972). Since then the taxonomic significance of variations in setal number, segment size andnumber of spermathecae has been demonstrated by Easton (1976). During the course of thepresent investigation it became apparent that further morphological specializations can usefullybe employed for generic and specific recognition. The following require comment. 1 Body shape The body shape of most species is approximately circular in cross-section although it may beflattened or concave ventrally in the region of the genital field. The spasmodic contraction of thearchiform muscles (Oishi, 1930) in the more anterior segments during preservation may in par-ticular give the body a flattened appearance. The majority of species included in Planapheretimaare arboricolous, these too have depressed bodies but with the longitudinal muscles grouped inpaired lateral blocks (Fig. 1). (Associated with this condition are cryptic coloration, crowdedventral setae and often a glandular ventral surface forming a 'creeping sole'.) It is assumed that the diameter : length proportion is constant for individuals of all species ofthe Pheretima group killed by a standard method (excluding regenerating specimens) as establishedfor Amynthas hupiensis by Grant (1955). 2 Setae Examination of long series of individuals show that, in the Polypheretima elongata species-complex, the number of setae on segment vii is positively correlated with the volume of that seg-ment and that two groups of taxa may be recognized with different setal densities (Easton, 1976).In Metapheretima sentanensis and M. triciae the setal densities are considerably higher and they ACAECATE PHERETIMOID EARTHWORMS 3 form a third group (Fig. 2). Unfortunately the majority of other species discussed in this report areknown only from one or few individuals. Nevertheless, it is possible to assign these taxa to one orother of the three groups recognized on the basis of data derived from the examination of asingle individual. The number of setae increase posteriorly usually to about segment xxx andthen decrease in number to the posterior end of the body (Beddard, 1895 : 291; Hatai, 1924;Sivickis, 1930). These variations are not included among the taxonomic criteria employed in thepresent revision. 0) 100-5 90g 80 "5 70 k. 60 50 3 Z 40 V* ^* " 8 o o L A A I I I I I I I I I I 1 2 3 456789 10 Segments! volume Fig. 2 Correlation between the number of setae and segmental volume of segment vii (scales logarith-mic). Setal densities: L, low (Polypheretima kinabaluensis); /, intermediate (P. elongata, everetti,phacellotheca and stelleri) ; H, high (closed circles - Metapheretima sentanensis, open circles -M. triciae). The setae are usually situated in a single ring around the equator of each segment, but in a fewspecies of Planapheretima and Metapheretima some may be displaced to form two or three rings.In most species the setae are regularly distributed around each segment, being rarely crowdedventrally or dorsally. However, in the majority of species of the genus Planapheretima the setaeare densely crowded ventrally (see Body shape}. The ventral and dorsal gaps in the setal ring (aa and zz) are often larger than the adjacent gaps(ab and yz) but seldom exceed twice the size of the adjacent gaps ; exceptionally in Archipheretimathey are much larger and in A. ophiodies the dorsal gaps are equal to one quarter of the bodycircumference. The conventional setal nomenclature has been followed throughout (Stephenson,1930). Penial setae occur rarely in the Pheretima group of genera and are unknown among the acaecatespecies. 3 Dorsal pores The location of the first dorsal pore is fairly constant in most species, usually occurring in theregion of 1 1/12 but it may be in any furrow between 5/6 and 13/14, even 19/20 in the case of Poly-pheretima coplandi. 4 E. G. EASTON 4 Clitellum The clitellum is usually restricted to three segments (xiv-xvi) but it may begin on xii or xiii andextend posteriorly to xvii or xviii. The clitellum is annular on segments xiv-xvii but may be in-complete ventrally on xii, xiii or xviii. All of the species of Polypheretima as well as the majorityof Metapheretima have clitella restricted to three segments. All of the species of ArchipheretimaandPleionogaster have extended clitella as do most of the species of Planapheretima. Occasionallyclitella are found to be poorly developed in fully grown individuals. This condition is believedto be characteristic of a postsexual phase (Gates, 1972a : 318). 5 Male pores The species investigated may be divided into two groups on the basis of the structure of the malepores. In the first, each male pore is situated in the centre of a circular or oval papilla, the poro-phore, which is often pigmented; crescentic genital markings are never associated with these pores(while the spermathecal pores are always small). In the second group the male pores do notdischarge through porophores and crescentic markings are often present (here the spermathecalpores may be small or large). In both groups the male pores may have accessory structures which show a wide range of intra-and inter-specific variation. Among these diversifications it is possible to recognize a morphologicalseries of increasing complexity in each group ranging from a simple superficial pore to a conditionin which the pore discharges into a copulatory pouch. In a separate study of the ontogenesis ofspecies possessing the more complex pore structures, it was found that during development eachindividual passes through successive growth phases which represent the condition of adults of lesshighly specialized species. The structure and development of the copulatory pouches in the twogroups differ yet the developmental processes are sufficiently similar for the two to be regardedas an example of parallel development. (a) Male pores on porophores. The total range of variation in the structure can be traced duringgrowth in Polypheretima elongata and, in the case of the more complex structure, P. koyana. In the immature condition (Fig. 3a-b) the circular porophore of elongata is faintly demarcatedwith a poorly discernible crescentic ridge enclosing the porophore. With increased maturityboth the porophore and the ridge become more distinct (Fig. 3c). During the next phase theporophore begins to invaginate along its lateral margin while its median edge often becomesraised above the surface of the body (Fig. 3d). At its maximum development in elongata, theporophore is almost completely enclosed leaving only a characteristic crescentic aperture to thecopulatory pouch visible on the body surface (Fig. 3e). In this species the copulatory pouch isrestricted to the body wall and does not invade the coelom; the porophore occupies the medialwall of the copulatory pouch. Juvenile individuals of Polypheretima koyana have copulatory pouches indistinguishable fromthose described above in mature adults of elongata (Fig. 3e). With increasing maturity the apertureto the pouch of koyana becomes a longitudinal slit and develops tumid lips while the porophoreoccupies the floor of the pouch (Fig. 3f). Insufficient material of this species is available to allowintermediate stages between figures 3e and 3f to be recognized. Male pores are on porophores in all species of Polypheretima as well as some species of Archi-pheretima and Planapheretima. The porophores may be within copulatory pouches in species ofPolypheretima. However, it is possible that when more mature individuals become available forstudy some of the species which are noted as having simple male pores will be found to have morecomplex structures. Chen (1946) described the porophores of Planapheretima continens as occasionally bearing apenis-like structure (Fig. 3g), this species has not been examined. However, during the examin-ation of an individual of elongata, a similar structure was observed which proved to be an artifactcaused by an incomplete removal of the cuticle. (b) Male pores lacking porophores. The stages in development of the male pore present in thespecies lacking porophores are represented in a series of individuals of Metapheretima kilii and,in the case of the most complex condition, M. oinakensis. ACAECATE PHERETIMOID EARTHWORMS Fig. 3 Development ot male pores, (a-f) Polypheretima; (g) Planapheretima continens; (h-1) Metapheretima. 6 E. G. E ASTON In an immature individual of kilii the male pore is at the centre of a low conical body (Fig. 3h).With increasing maturity the conical body increases in size and elevation (Fig. 3i), and the upperportion finally develops into a slim, penis-like structure (Figs 3j-k). In oinakensis the male pore is terminal on a slim penis similar to that found in kilii (Fig. 3k),but it is incorporated within a copulatory pouch (Fig. 31). The intermediate stages by which thisform of copulatory pouch develops are unknown, but in view of its different structure they areunlikely to be similar to those found in elongata. Development possibly involves the invaginationof the body wall around the whole periphery of the basal end of the penis. Male pores lack porophores in all species of Metapheretima and Pleionogaster and some speciesof Archipheretima and Planapheretima. The male pores may be in copulatory pouches in speciesof Metapheretima. Several species (Metapheretima deirdrae, jocchana and sembaluensis, Pleiono-gaster horsti. Planapheretima maculatd) have male pores considerably larger than those usuallyencountered. In two species. Archipheretima ophiodies and Planapheretima hasselti, the male pores are onraised areas which extend onto xviii-xx and xvii-xix respectively (Figs 12a and 29b). 6 Female pores The female pores are either paired or single, occurring ventrally on the equator of segment xiv.Occasionally individual variants may have paired female pores, although they belong to speciesin which the pore is usually single, the converse condition also occurs. 7 Genital markings Glandular areas and other markings are present on the ventral surface of the anterior body wallof both clitellate and aclitellate individuals of many species. The nature and arrangement of thesemarkings are specifically distinct and so provide valuable diagnostic information. They varyintraspecifically but these differences (degree of development and number of markings) may beattributed principally to growth since the patterns are usually constant in mature worms.(a) Diffuse genital markings with poorly defined periphery are present only in the Archipheretimairis species-group where they are always intersegmental (Fig. 4a). (6) Discrete genital markings with clearly defined periphera commonly occur in all of the generarevised below, they are usually segmental and only rarely intersegmental. These markings areusually circular or oval and differentiated into two or more concentric areas (large markings,Fig. 4b, small Fig. 4d) ; rarely, in Polypheretima aringeana, the central area of each genital markingis differentiated into small spots (Fig. 4e). The glandular tissue associated with the markings isusually restricted to the body wall, termed 'sessile' (Gates, 1972). In species with very smallmarkings, such as grata, the glandular tissue may invade the coelom in the form of a stalkedgland. (In grata genital markings are present within the copulatory pouches but absent from theexternal, postclitellar ventral body surface.) The genital markings on segment xviii are often similar in shape and position to those on ad-jacent segments, but they may be crescentic in shape and are closely associated with the malepores (Fig. 4c). Crescentic markings are present in Metapheretima (distinguishing the genus fromPolypheretima), Pleionogaster and possibly two species of Planapheretima (celebensis andmoultoni). Histologically crescentic markings are indistinguishable from the more commoncircular and oval genital markings. (c) Annular ridges encircle the male pores in several species of Metapheretima (orcrista, parmata,glamdringi, jocchana) and one species of Planapheretima (maculatd). Several other species ofMetapheretima, all members of the oinakensis species-group, have similar, but less extensivelydeveloped structures. Functionally these structures would appear to facilitate the transfer ofsperm between opposing male and spermathecal segments during copulation. 8 Septa In the oesophageal and pharyngeal regions septa are often absent, incomplete or thickened.Considerable variation exists within a species and septal characters appear to be of little diagnostic ACAECATE PHERETIMOID EARTHWORMS 7 value (especially in view of the imprecise terms 'delicate', 'membranous', 'thickened', etc., whichare used in descriptions). The absence or incomplete development of the septa associated with thegizzard (8/9 and 9/10) and, when present, the oesophageal pouches (10/11 and 11/12) can becorrelated with the degree of development of these organs. In Pleionogaster, in which the oeso-phageal gizzard is vestigial, the anterior septa are uniform. The septal muscles form part of the musculature of the hydrostatic skeleton (Chapman, 1958).Thickened muscular septa may therefore be indicative of an active burrowing species, certainlythe musculature is poorly developed in arboricolous forms whose functional requirements aredifferent. ^ --.--.- ."jS'.'. d e Fig. 4 Terminology of genital markings, (a) diffuse; (b) large discrete; (c) crescentic; (d) smalldiscrete; (e) Polypheretima aringeana type. 9 Alimentary canal Within the Megascolecidae (sensu Gates, 1959) the Pheretima group of genera is characterized bythe presence of an oesophageal gizzard in viii. In most species the gizzard is well developed,invading the next two posteriad segments, but in the monotypic Pleionogaster it is vestigual andits function is taken over to some extent by the intestinal gizzards which characterize the genus.Oesophageal pounches, structures of unknown function, may be present in some species ofMetapheretima. They are usually paired, flexed anteriorly, and arise from the dorsal surface ofthe oesophagus immediately posteriad to the gizzard. The extent of their development variesconsiderably among the series examined; they are often darkly pigmented and always have awell-developed blood supply. Intestinal caeca are absent from most of the species investigated with the exception of a fewAsian species of Planapheretima. In some of the latter and several related acaecate forms, theintestinal wall was reported as being glandular (Chen, 1946) but it has not been possible to ex-amine material and the taxonomic significance of this specialization is uncertain. 10 Lateral hearts Four pairs of circumoesophageal contractile blood vessels are usually present, one pair in each ofx-xiii, although the posterior or anterior pair may be absent or incomplete. As the number of 8 E. G. EASTON pairs often vary individually within a species, the differing conditions are of little taxonomicsignificance. 11 Anterior male reproductive system The majority of species of the Pheretima group are holandric (testes paired in both x and xi) asare all of the known species of Archipheretima, Planapheretima and Pleionogaster. Species with aproandric condition (testes paired in x only) are rare and acaecate examples are accommodatedin Metapheretima (with the possible exception of sibogae in Polypheretima). Metandric species(testes paired in xi only) occur in both Polypheretima and Metapheretima; in the former genusmetandry is restricted to (and diagnostic of) members of the badia and patae species-groups.However, in Metapheretima the character has a limited taxonomic value since metandry is presentin most of the species-groups recognized. With the possible exception of several species of Archipheretima, the testes are invested by toughmembranous sacs in all species of the Pheretima group, including Polypheretima fida, althoughtestes sacs were recorded as being absent in this species (Michaelsen, 19136; Stephenson, 1930).In Archipheretima the sacs are usually more delicate and larger, mostly forming a lining to theparietal wall, although they have been reported as absent in some species (Gates, 1970a). The shapeand the extent of the testes sacs varies with genus, species and to some extent with the maturity ofan individual. In a few species the seminal vesicles and lateral hearts may also be enclosed withinthe testes sacs. The seminal vesicles are paired, posteriorly directed, sac-like evaginations of the hinder septaof each testes segment. In most species each pair is restricted to one segment where their size varieswith maturity, but in several Chinese species of Planapheretima, they extend several segmentsanteriorly and posteriorly. Small, paired sacs which resemble the seminal vesicles may be present on the posterior surfacesof septa 12/13 and 13/14. These structures of unknown function have been termed ovisacs (Bed-dard, 1895), coelomic sacs (Sims & Easton, 1972) and pseudoseminal vesicles (Gates, 1972). It isproposed here to adopt the term pseudoseminal vesicles, to avoid confusion with other structuresdescribed as coelomic pouches and coelomic sacs by Beddard & Fedarb (1902). 12 Ovaries The female gonads are paired and free in xiii in all the species investigated as well as the majorityof other species of the Pheretima group. However, the ovaries are enclosed in delicate walledsacs in Pithemera mira and several related taxa from New Britain and nearby islands (Gates,19726). 13 Spermathecae The duct and ampulla of each spermatheca are distinctly demarcated in mature individuals ofmost of the species reviewed here. In immature specimens, and mature examples of Archiphere-tima, the duct merges gradually into the ampulla. In species of the acaecate genera a diverticulum(rarely several diverticula) arises from the spermathecal duct and provides a useful diagnosticcharacter for generic, species-group and specific identifications. Several types of diverticula areencountered (Fig. 5). The spermathecal pores may be either small (and difficult to see) or large, often within tumidlips. Gates (19720 : 150) described the large spermathecal pore as secondary since he recognizeda minute (primary) pore within the invagination. The taxonomic aspect of this specialization wasnot investigated during the present study. The number and situation of spermathecae may vary within a thecal segment. These variationsare reflected in the arrangement and number of spermathecal pores which are often diagnosticof species-groups and species. The pores may be segmental as in Polypheretima annulata and P.voeltzkowi or, more usually, intersegmental. In both situations they occur either in a single furrow,or segment, or in several consecutive furrows between 4/5 and 8/9, even 7/8/9/10 in the case ofMetaphire sanseiana (Ohfuchi, 1951). When monothecate there is a single pore either dorsally or ACAECATE PHERETIMO1D EARTHWORMS 9 ventrally placed in each segment (a single lateral pore indicates an abnormal example of a bithe-cate species). Bithecate species have two symmetrically placed pores, while numerous poresarranged in paired symmetrically placed batteries are external evidence of polythecate species.Most species are monothecate, bithecate or polythecate but some may be divided, being,for example, bithecal in some segments and polythecal in others. Immature specimens of poly-thecal species may be bithecal while the number of spermathecae in the batteries of the species ofthe Polypheretima elongata species-complex increases with maturity (Easton, 1976). In bithecal and polythecal species the ventral separation of the pores (or batteries) can beexpressed as a fraction of the body circumference at that segment. This proportion is reasonablyconstant in a taxon and often diagnostic. In this paper the separation of the most posterior sper-mathecal pores is utilized since occasionally the more anterior pores are more closely paired. Fig. 5 Spermathecae. (a) differentiated with simple ectal diverticulum ; (b) differentiated withsimple ental diverticulum; (c) undifferentiated with multilocular diverticulum (Archipheretimd)',(d) differentiated with multilocular diverticulum (Metapheretimd); (e) differentiated with numerousdiverticula. 14 Nephridia The nephridia were excluded from the present numerical and taxonomic investigations due to theuncertainty about their systematic significance (see Classification) and for much the same reasonsthat they were omitted by Sims & Easton (1972). The study of the nephridia would necessitate thedestructive dissection of well-preserved specimens, and it was clearly undesirable to go to suchextreme lengths to obtain information. Secondly, some species are represented by specimens oftenin poor condition due to either inadequate fixation, or previous dissections, so that informationcan no longer be obtained from them. Only a minority of the original descriptions include detailsof the nephridial system, so that it would be difficult to correlate this information. Nevertheless, variations in the nephridial system of a few species were studied for other reasonssince, in the most recent classification of the Megascolecoid earthworms, Jamieson (197 la & b)attributed considerable systematic importance to the structures of the excretory systems (seeClassification). Numerical studies Introduction Since only 14 acaecate species were assessed in the numerical investigations of Sims & Easton(1972), it was decided to subject the majority of the 92 species recognized here to afuller numerical appraisal. The taxa selected for study and the characters assessed are listed inTables 1 and 2 respectively. The data utilized was extracted from the specific descriptions in thetaxonomic section of this paper, instead of from the examination of a single individual whichhas been the practice of earlier authors. The techniques used resemble those employed by Sims &Easton (1972) but the analyses were performed with the aid of a program adapted from theCLASP computer program (Gower & Ross, Rothamsted Experimental Station) for use with theVarian V72 computer in the British Museum (Natural History). The mutual similarity coefficients 10 E. G. E ASTON of the taxa investigated were calculated using a coefficient of similarity defined for both quantita-tive and qualitative characters. A two-dimensional plot of the taxa involved was obtained usingthe method of principal co-ordinates analysis and a Minimum Spanning Tree (MST) was addedto the plot. Table 1 List of taxa studied in numerical investigations * Species not included in the initial numerical study. Four separate numerical investigations were made. Firstly, a general study was undertaken tore-appraise the 'acaecate' genera recognized by Sims & Easton (1972). One result of this study wasthat Ephemitra is merged with Metapheretima, which is itself restricted, and the excluded speciesare here accommodated in Polypheretima. Then followed independent studies of each of the generaMetapheretima, Planapheretima and Polypheretima to detect the phenetic inter-relationships oftheir component species. Comparable information on the small genus Archipheretima is obtain-able from the initial, general computations while Pleionogaster is monotypic. The results of thesestudies are discussed under each genus in the taxonomic section. General Study Seventy-eight species were utilized to provide data for the re-appraisal of the genera recognizedby Sims & Easton (1972). It was not possible to include all of the species listed in Table 1 becauseof the limited capacity of the computer program employed, the taxa marked by an asterisk werethose excluded from this study. ACAECATE PHERETIMOID EARTHWORMS 1 1 The configuration of the taxa with the first and second vectors of the principal co-ordinatesanalysis as axes is shown in Fig. 6. A considerable degree of clustering is evident, which becomesclearer with the addition of the Minimum Spanning Tree (MST) with graded linkages. Four majorclusters may be recognized. Two, indicated by square and triangular symbols, comprise the sixspecies of Archipheretima and 14 species of Planapheretima respectively, which by their discrete-ness and the low values of the MST linkages with other clusters confirm the validities of thegenera. The two other clusters, indicated by closed and open circular symbols contain the taxa Table 2 Characters used for computing coefficients of similarity 1 Mean longitude 2 Mean latitude 3 Ratio of lengths of arcs containing first five dorsal setae (v-z) : first five ventral setae (a-e) on segmentvii 4 Shape of body in cross-section : circular or depressed 5 Creeping sole : present or absent 6 Segment number of anterior end of clitellum 7 Segment number of posterior end of clitellum 8 Size of spermathecal pores : large or small 9 Ratio of distance apart of posteriormost spermathecal pores : circumference of body 10 Position (furrow number) of anteriormost spermathecal pores (one 'furrow' = setal row - setal row) 1 1 Position (furrow number) of posteriormost spermathecal pores 12 Position of spermathecal pores: postsetal, intersegmental, or presetal 1 3 Main number of spermathecal pores per furrow 14 Origin of spermathecal diverticula: ectal or ental 15 Condition of spermathecal diverticula: single or multiple 16 Condition of male pores: crescentic copulatory pouches, slightly invaginated porophore, superficialporophore, superficial lacking porophore, penate simple or penate within copulatory pouches 17 Size of male pore (superficial lacking porophore only): large or small 18 Ratio of distance apart of male pores: circumference of body 19 Annular ridges associated with male pores: absent or present 20 Crescentic markings associated with male pores : absent or present 21 Form of genital markings : diffuse or discrete 22 Postclitellar genital markings (discrete only) number on each segment 23 Glands associated with genital markings : sessile or stalked (discrete only) 24 Oesophagus : simple, slightly pouched, or distinctly pouched 25 Intestine: caecate, simple, with gizzards 26 Intestinal wall : unspecialized or glandular 27 Number of first intestinal segment 28 Condition of testes : proandric, holandric or metandric 29 Condition of testes sacs : absent, large membranous, annular, large paired, small paired previously assigned to Metapheretima by Sims & Easton (1972). The species identified by closedcircular symbols have male pores which lack porophores but usually have crescentic markingsassociated with them. The male pores sometimes discharge from within copulatory pouches whenthey are on elongate penes. The taxa principally from the Papuan region, have diverse types ofspermathecal diverticula and genital markings which are usually in longitudinal rows. Includedin this cluster are the type species of Metapheretima Michaelsen, 1928 and Ephemitra Sims &Easton, 1972. The taxa indicated by open circular symbols have the male pores on porophoreswhich lack associated crescentic markings. These male pores sometimes discharge into copulatorypouches when the porophore forms a short truncate penis. The taxa, which come from all partsof the Pheretima group domain, always have simple spermathecal diverticula, but togetherexhibit a wide diversity of patterns of genital markings. The type species of Polypheretima isincluded in this cluster. The degree of separation of the clusters and the evidence of the MSTlinkages permit the recognition of two distinct genera Metapheretima and Polypheretima. 12 E. G. EASTON 36 86*- \ Species 72-85 - Fig. 6 Principal co-ordinates analysis of 78 'acaecate' species : the configuration of the species withthe vectors corresponding to the first and a second latent roots. The linkages of the added Minimum Spanning Tree are graded to indicate percentage similarities; , +95%; , 90-95%; , -90%. The genera recognized are depicted thus: Pleionogaster - star-shaped symbol; Metapheretima - closed circular symbols; Polypheretima - open circular symbols; Archipheretima- square symbols ; Planapheretima - triangular symbols. ACAECATE PHERETIMOID EARTHWORMS 1 3 The species horsti, represented by a star in Fig. 6, is linked by the MST to Metapheretima(indicated by closed circular symbols) at 90-0% similarity. This value is higher than many of theMST linkages within Metapheretima and the locus of horsti is closer to the centre of the clusterthan several taxa of Metapheretima, notably jocchana (36). Nevertheless, horsti is the type speciesand only representative of the genus Pleionogaster which is unique among the Megascolecidae inpossessing intestinal gizzards. Since this character is not only unique but also considered by mostworkers to be of considerable systematic importance, it is proposed to retain this genus as aseparate entity. Except for these changes, the numerical results are in accord with those of Sims & Easton(1972), when a dissimilar set of morphological attributes were coded and processed on a largercomputer. These authors indicated that the species accommodated here in Polypheretima could bedistinguished from other acaecate forms, but they were uncertain of the taxonomic significance ofthe diagnostic characters of this group, and refrained from separating the species taxonomically. Distribution The distribution of the acaecate members of the Pheretima-group of genera need to be discussedin the context of the indigenous ranges of all the species within the group. Moreover, assessmentsof the affinities and origin(s) of the individual pheretimoids need to be considered in the light ofthe wider distribution of the group as a whole. The Pheretima group domain The concept of the Pheretima group domain, the area in which all of the autochthonous speciesof the Pheretima-group of genera occur (Fig. 7), was pioneered by Michaelsen (19036, 1908,19286). In the last work the area was defined as comprising Japan, China, Burma through south-east Asia and the Indo- Australasian Archipelago to Queensland then to New Caledonia, the NewHebrides, the Caroline Islands and, tentatively, the Comoro Islands. The results of recent col-lecting now make it possible to establish most of the boundaries with greater precision. The nor-thern limit is bounded by the most northerly records of Metaphire agger a (Kobayashi, 1934) whichform a line linking Chihfeng, Yamhsin (Chinhsein) and Tashihkiano (Tashihchiano) in Man-churia with P'yongyang (Heijo) and Kumgang-san (Mt Kongo) in Korea (Kobayashi, 1940). Inthe west, Chen (1931, 1936, 1946) recorded a rich indigenous fauna from Szechwan Provincewhile Gates (19720 : 149) recognized that the Chindwin-Irrawaddy axis marked the westerlylimit of the domain in Burma. In the south only a single indigenous representative of the Pheretimagroup, Amynthas queenslandicus (Fletcher, 1887), has been recorded from Australia since enchy-traeoides Michaelsen, 1916, also from Queensland, was shown by Gates (1961) to be a synonymof the peregrine species A. minimus (Horst, 1893). Expeditions organized by Dr B. G. M. Jamiesonhave collected several new indigenous species in northern Queensland, although only peregrinespecies were found in Northern Territory (Easton, in prep.). It seems certain, therefore, that muchof the tropical forest of Queensland belongs to the domain. The precise eastern limit of the domainis uncertain, since several species have ranges which include Pacific islands. Species have beendescribed from the Marianas, Caroline Islands, Solomon Islands, New Hebrides and LoyaltyIslands, which have not been encountered in other parts of the domain and it seems reasonable toto follow Michaelsen (19286) and include at least these islands within the realm. The ComoroIslands also possess a species of the Pheretima group which does not occur elsewhere. AlthoughMichaelsen (19286) included the Comoro Islands within the domain, in view of the evidencediscussed below, these islands are here excluded. It is evident that the Pheretima group domain extends throughout the forested lands of Asiaand Australasia, but it is curiously restricted in some areas. In the north and northwest the limitingfactors are apparently climatic. In Korea and Manchuria the northern boundary coincides withthe 8 isotherm (annual mean temperature), and in Manchuria the western limit of the domain ismarked by the 400 mm isohyet (Kobayashi, 1940). It is possible that isolated populations mayoccur in moist refuges to the west of the 400 mm isohyet since it has been suggested (Wadia, 1960)that the dessication of central Asia is a post-glacial phenomenon. To the southwest the 400 mm 14 E. G. E ASTON Polypheretima Metapheretima Archipheretima Planapheretima Pleionogaster Fig. 7 Geographical limits of the Pheretima group domain and the distribution of the acaecate genera. isohyet enters the Himalayas, where low precipitation and temperature provide a major barrierto earthworm migration. Further south there are neither rainfall nor temperature barriers of any significance which maybe correlated with limits of the Pheretima group. Nevertheless, a discrete boundary can be seen toexist and here it is necessary to examine the Caenozoic palaeogeography of Asia and PeninsulaIndia to understand the pattern of distribution. During the Mesozoic when the Tethys oceanseparated Peninsula India from Asia the direct interchange of earthworm faunae was not possible.In the Tertiary era conditions changed and the Indian and Asian plates approached their presentrelative positions. Western Burma and Bangladesh remained a barrier to earthworm migrations,since the Cretaceous and Tertiary sediments in this area did not become land to any great extentuntil the end of the Pliocene (1-5-3-5 million years ago) (Wadia, 1953). In Burma proper, althoughthe ridges of the Chin hills/Araken Yoma and Pegu Yoma were formed during the Eocene andMiocene respectively, the intervening valleys remained below sea level even during the Pliocene(Krishnan, 1952). When the land links were eventually established the Pheretima group could haveinvaded Peninsula India from the east, but only the more successful peregrine species apparentlydid so. These occur nowadays throughout much of southern India and they may have attainedthis distribution unaided but in view of their occurrence on other continents it is likely that theywere assisted adventitiously by man. Most of the non-peregrine species of this area remain confined ACAECATE PHERETIMOID EARTHWORMS 1 5 to the east of the Chindwin-Irrawaddy axis. This faunal limit lies between 100 and 150 km westof a line from the Irrawaddy south to Mandalay to the foot of the Shan plateau to the Sittangvalley, i.e. the boundary of the Asian archean rocks (Rao, 1974 : 238). In Australia the limiting factors forming the southern boundary of the Pheretima group domainare not known precisely but they appear to be largely ecological. As most Megascolecoidea (Megascolecidae sensu Jamieson, 197 la and Eudrilidae) are indi-genous on land masses which once formed part of Gondwanaland, it seems likely that they evolvedin this region and that their precursors existed in Gondwanaland prior to the Mesozoic break upof this ancient continent. The presence of the Pheretima group and other Megascolecid speciesin southeast Asia and the occurrence of several genera in North America, is probably due toinvasions of these Laurasian land masses from the widely dispersed fragments of Gondwanaland.In this model of Megascolecoid dispersal, the origin of the Pheretima group would lie in NewGuinea and northern Australia since these are the only major Gondwanaland derived areasinhabited by indigeneous species. The invasion of Asia by way of the Indo-Australasian Archi-pelago could therefore have followed the collision of the Australian and Asian Plates during theMiocene, 7-26 million years ago (Raven & Axelrod, 1972). If the primordial pheretimoids had emerged before the Mesozoic breakup of Gondwanaland,it would have been possible for them to have migrated westwards to other regions and give riseto the species suspected of being indigenous in the Comoro Islands. However, the absence of anysurviving indigenous species in the intervening areas, and the paucity of the Pheretima group inthe Malagasian fauna, makes this seem unlikely. Emigration may have occurred eastwards to theSolomon Islands, New Hebrides and New Caledonia which, prior to 80 million years ago, werejuxtaposed to Queensland (Griffiths, 1971). It should be noted, however, that today the Pheretimagroup is not indigenous in New Zealand although these islands too rifted from the easternmargin of the Australian Plate at that time. Other mechanisms by which earthworms may havecolonized oceanic islands were discussed by Stephenson (1930). Distribution of the 'acaecate' pheretimoids The individual acaecate genera, although often sympatric, have dissimilar ranges (Fig. 7). Archi-pheretima is restricted to Borneo and the Philippines while the genera Polypheretima and Plana-pheretima are the most widespread, occurring throughout the Indo-Australasian archipelago to thenorthern and western limits of the Pheretima group domain. In Asia, they are now restricted toisolated refuges so presumably they were once continuously distributed throughout the area.Metapheretima is restricted principally to New Guinea, where it is the commonest acaecatepheretimoid. The monotypic genus Pleionogaster, closely allied to Metapheretima (see numericalstudies) and probably a product of the Metapheretima radiation, is recorded only from the Philip-pines and possibly the Moluccas. The genera Polypheretima, Planapheretima and Metapheretimaprobably represent three radiations from the Papuan area. The species-groups comprising the genus Metapheretima are largely sympatric and there isseemingly insufficient evidence to recognize any evolutionary patterns among them. Similarly,the ranges and morphological variation of the species of Archipheretima are too poorly known topermit valid conclusions to be drawn. The infra-generic assemblages recognized within Polypheretima are, on the other hand, mainlyallopatric and when their ranges are considered together with their morphological variations, theinformation provides a means of tracing the probable evolution of the genus. The species-groupsof Polypheretima (see taxonomy section) form a series in which the morphological specializationsincrease as the geographical ranges decrease (Fig. 8). The most widespread, the bifaria species-group (Division I), is holandric with simple male pores (the species grata, voeltzkowi and theannulata species-complex, also members of Division I, are considered to be local specializations) ;the polytheca species-group (Division II) is similarly holandric but the male pores open withincopulatory pouches ; while the most restricted in their distributions, the badia and patae species-groups (Division III), not only have male pores within copulatory pouches but also they aremetandric. Although the badia and patae species-groups apparently have high mutual affinities(see Taxonomy section), in view of their widely separated ranges, it is probable that they have 16 E. G. EASTON developed metandry independently. Possibly the bifaria, polytheca, badia and patae species-groupsrepresent successive radiations which occurred in different parts of the range of Polypheretima.These radiations are probably of considerable antiquity since the ranges of the species-groupscannot be correlated with either Wallace's or Weber lines. Two species for example, P. elongataand everetti, even occur on both sides of Wallaces line. annulate species-complexbifaria species -group& grata polytheca species-group patae species -group badia species -group limits of ranges uncertain Fig. 8 Polypheretima: geographical distribution of the component species-groups. The two divisions of Planapheretima are also allopatric. Species of Division I have unspecializedintestines and occur in the Indo- Australasian archipelago while those of Division II have special-ized intestines and are indigenous to the Asian mainland. Probably precursors of Division IIhad simple intestines but whether this group arose in Asia is more speculative (see taxonomysection). In the northwestern and southeastern limits of the Pheretima group domain the acaecate generaoccur only sporadically in isolated refuges, here the Pheretima group is represented mainly by thecaecate genera Amynthas, Metaphire and Pheretima s.s. Many of the Asian species of Amynthasand Metaphire differ from species of Polypheretima only in the possession of intestinal caecaewhile most of the Papuan and Australian species of Amynthas may be considered to be caecateanalogues of Metapheretima. Since the possession of intestinal caeca is a specialization, the caecatespecies may have emerged independently more than once, possibly from this acaecate stock andhave replaced them in the northwestern and southeastern parts of the domain. ACAECATE PHERETIMOID EARTHWORMS 1 7 Classification For some time the opinion has been often held that 'the key to the classification of the ... (ter-restrial oligochaeta) is to be found in the modifications of the excretory system' (Beddard, 18906).The result is that the structure of the nephridial system has played an increasingly important partin earthworm classifications, although its application often has been hampered by the paucity ofavailable information. During the last two decades several disparate classifications of Megascole-coid earthworms have been proposed (Omodeo, 1958; Gates, 1959; Lee, 1959; Jamieson, I91la& b). In the latest Jamieson divided the Megascolecinae, which includes the Pheretima group ofgenera, into three tribes. The tribes Dichogastrini and Megascolecini both include genera withcombined male and prostatic pores, and a meronephridial excretory system. In genera assigned tothe former tribe the median nephridia are exonephric ; while in those of the latter tribe, mediannephrida are enteronephric or absent. Enteronephridia have been recorded from no more thanfive species of the Pheretima group of genera; Metaphire posthuma by Bahl (1919), Amynthashupiensis by Grant (1955), tentatively in Pleionogaster horsti by Gates (1943) and possibly inAmynthas hawayanus and A. diffringens by Bahl (1919) although the identities of the specimensrepresenting these species have been questioned (Gates, 19376). Jamieson (197 la) accepted Bahl's(1946) syllogism that since a few species of Pheretima possess enteronephridia so all members ofthe genus (now the Pheretima group of genera) have them too, therefore he assigned the group tothe enteronephric tribe Megascolecini. Due to the importance accredited to the structure of the nephridial system and the paucity ofdata available for most species of the Pheretima group, the nephridial systems of examples of theacaecate genera were examined. Comparisons were made with the description of Bahl (1919) whorecognized three types of nephridia in M. posthuma. 1. Tufted nephridia, present in the segments anterior to the gizzard and discharging into thepharynx. 2. Body wall nephridia, present in all segments except i. These are numerous, Bahl recorded200-250 in a segment and Grant (1955) reported 175 in each segment in A. hupiensis. Bahlreported that in M. posthuma each nephridium discharged independently but Beddard (1888)stated that in A. hawayanus each nephridium was linked by a reticulum to other nephridia, bothof its own and of adjacent segments. [It should be noted that Beddard (1888) provisionally identi-fied the specimens as aspergillum but later (1895 : 43) he established that they were bermudensis =hawayanus.] Spencer (1888) reported a similar nephridial reticulum in Megascolides australis. 3. Median nephridia, present on septum 15/16 and posteriorly to the end of the body. Eighty toone hundred nephridia are present on the anterior and posterior surfaces of each septum in M.posthuma and 70-80 in the case of A. hupiensis (Grant, 1955). In both species, the nephridia areenteronephric in that they are linked by paired, postseptal ducts which run dorsally and medianlyto discharge into paired supraintestinal ducts, these in turn discharge, at intervals, into the in-testine. In this present study, examples of two species, Metapheretima sentanensis and Polypheretimataprobanae, were examined in detail and examples of four other species, M. neoguinensis (typespecies of Metapheretima), P. stelleri(type species of Polypheretima), P. elongata and Pleionogasterhorsti (=jagori, type species of Pleionogaster) were compared with them. The specimens examinedhad been preserved in alcohol for several years prior to study, so they were stained with methyleneblue to enhance the recognition of the decolourized internal structures. Modifications and varia-tions were found in each of the three types of nephridia described above among the speciesexamined (Table 3). 1. Tufted nephridia are present in iv-vi in all of the species examined. The nephridia occur aspaired lateral masses on the peripheries of the anterior surface of the septa and paired excretory(?) ducts can be traced passing between each nephridial mass and the pharyngeal mass. Additionaltufted nephridia are present in vii and viii in neoguinensis and in vii-ix in horsti and sentanensis.When the posterior septa of these segments are absent or incomplete the nephridia form pairedlateral bands on the body wall. In sentanensis paired excretory ( ?) ducts can be traced passing from 18 E. G. EASTON ACAECATE PHERETIMOID EARTHWORMS 1 9 the nephridial masses of vii and viii forward to enter the body wall in the vicinity of the spermathe-cal pores. In xi where each lateral band is subdivided into three discrete masses, no ducts can berecognized. Gates (1943) first described the tufted nephridia of vii-ix in horsti and similar structureshave been recognized in several species of Lampito (Bahl, 1924) and Megascolex (Vata, 1945). 2. Body wall nephridia vary in number according to the species and the region of the body studied,they are however always absent from the anteriormost segments. In horsti and sentanensis theyare particularly sparse (c. 10 and c. 20 per segment respectively). The external nephridioporesdescribed by Beddard (1888) and Bahl (1919) cannot be recognized. The reticulum described byBeddard (1888) appears to be present although transverse microsections need to be studied toconfirm this observation. Fig. 9 Metapheretima sentanensis: schematic diagram of a transverse section through theequatorial region of a posterior segment showing the semiannular sinuses and associated nephridia. In the posteriormost segments of two of the specimens examined (sentanensis and taprobanae)the body wall nephridia of each segment apparently discharge into a pair of semi-annular lateralsinuses (Fig. 9). Excretory ducts leading to external pores are apparently absent. These structuresmay be analogous to the coelomic pouches of M. posthuma described by Beddard & Fedarb(1902), but it is possible that they are artifacts resulting from the epithelial lining of the coelombecoming detached during fixation or preservation. 3. Median nephridia are present in all of the species studied, but their numbers and positions varyfrom species to species. In elongata and stelleri they are sparse and close to the body wall and areapparently linked to the reticulum of the body wall nephridia. In horsti a single pair of largenephridia with preseptal funnels are present from septum 18/19 and Gates (1943) tentativelyrecognized a pair of postseptal excretory ducts leading to the dorsal portion of the intestine ineach segment. In taprobanae there are numerous nephridia with preseptal funnels on each septumfrom 15/16 to the posterior end of the body. They lie in paired lateral arcs approximately halfwaybetween the intestine and the body wall. In sentanensis a single pair of nephridia with preseptalfunnels are present on septum 43/44, but the number of nephridia increase posteriorly to septum70/71 where there are about 40 with preseptal funnels and 20 with postseptal funnels. The neph-ridia then decrease in number until septum 90/91 where there are about 10 with preseptal funnelsand only two or three with postseptal funnels. Where they are reduced in number, the nephridiaare dorsally situated. In neoguinensis, the nephridia are close to the periphery of each septum,occurring regularly through the body from septum 18/19. Discussion From this brief morphological survey it emerges that the nephridial systems of the speciesexamined differ considerably, although they all possess median nephridia. Enteronephric ducts. 20 E. G. EASTON diagnostic of the Megascolecini (Jamieson, 1971a & b) and recorded in Metaphire posthuma byBahl (1919) and Amynthas hupiensis by Grant (1955), could not be identified in any of the speciesstudied although exonephric ducts, diagnostic of the Dichogastrini (Jamieson, 197 la & b),appear to be present in Polypheretima elongata and P. stelleri. As nephridial structures characteristic of two of these different tribes are present within thehomogeneous assemblage of species forming the Pheretima group of genera, it seems that thesestructures are unreliable characters for higher classification. If they were accepted, then membersof the Pheretima group would be distributed between the Dichogastrini and the Megascolecini.Clearly this would be unacceptable. Until new taxonomic criteria can be recognized, or evidenceconflicting with the results of the phenetic study become available, it is intended to revert to theolder classification of Megascolecoid earthworms proposed by Gates (1959) within which thePheretima group can be more readily accommodated. The Megascolecidae (Gates, 1959) - 'species with racemose prostates of the Pheretima type,without a central lumen and presumably of mesodermal origin' - includes the Pheretima groupof genera (c. 760 nominal species) and about thirteen other genera with approximately 280 species.Similarly, the tribe Megascolecini Jamieson, \91\a & b accommodated ten genera containingabout 210 species in addition to the Pheretima group. Of the 280 species in the Megascolecidaesensu Gates, some 130 are from the Indian region, 130 from Australia and the residue from NewZealand. As previously mentioned, the Pheretima group originated on the Australian Plate so itsclosest allies might be expected to be present among the indigenous Megacolecidae of Australia. Taxonomy The component species of the Pheretima group of genera are readily distinguishable from themembers of the other genera forming the family Megascolecidae (sensu Gates, 1959) by the pre-sence of an oesophageal gizzard in segment viii. The gizzard is usually well developed to the extentthat it often lies within the parietes of not only segment viii but also segments ix and x. In Pleiono-gaster, however, the oesophageal gizzard is only vestigial and here it is replaced functionally byintestinal gizzards which are diagnostic of the genus. Additionally all pheretimoids are peri-chaetine. The species of this group of genera form two loose assemblages ; those with a pair of lateralcaeca or a single median caecum arising from the anterior region of the intestine, and those withoutthis specialization. The latter category, the 'acaecate' species are revised here and assigned to fivegenera : Archipheretima, Metapheretima (inc. Ephmitra), Planapheretima, Pleionogaster and Poly-pheretima. On the basis of the numerical investigations described above and detailed under thegenera concerned, the species are often placed in divisions and species-groups also, in twoinstances, species-complexes are recognized. Some of these infra-generic categories may representsuperspecies while others may, in time, be considered to represent subgenera, but until furtherinformation becomes available, they should be regarded as being no more than aggregations ofmorphologically similar species placed together to facilitate identification. They are not co-ordinate, even within any one genus. One of the species-complexes recognized was erected tocontain five closely allied taxa comprising the Polypheretima elongata species-complex (Easton,1976). At the present time the mutual relationships of these taxa are unknown, in many ways thecomplex resembles a polytypic species. The majority of acaecate species are known from only one or two series, and whenever possibleexamples of all known records have been examined in this study. The following abbreviations havebeen utilized to denote the institution in which material is deposited. Adelaide South Australian Museum Amsterdam Zoologisch Museum, Universitat van Amsterdam Berlin Museum fur Naturkunde an der Humbolt-Universitat zu Berlin Bogor Museum Zoologicum Bogoriense, Bogor, Indonesia BMNH British Museum (Natural History) Cambridge University Museum of Zoology, Cambridge, England Genoa Museo Civico di Storia Naturale 'Giacomo Doria' ACAECATE PHERETIMOID EARTHWORMS 21 Hamburg Zoologisches Institut und Zoologisches Museum, Universitat Hamburg Honolulu Bernice P. Bishop Museum Leiden Rijksmuseum van Natuurlijke Historic New York American Museum of Natural History Stockholm Naturhistoriska Riksmuseet Turin Museo ed Institute di Zoologica Systematica, Universita di Turin Vienna Naturhistorisches Museum Wein Aclitellate and clitellate individuals among the material examined are indicated by the letters Aand C respectively. Key to the genera of the Pheretima group 1 Setae crowded ventrally, creeping sole present, body usually flattened dorsoventrally Planapheretima (p. 64)Setae not crowded ventrally, creeping sole absent, body always cylindrical ... 2 2 Intestine lacking caecum(a) or gizzards 3 Intestine with gizzards ......... Pleionogaster (p. 114) Intestine with caecum(a) ............ 5 3 Crescentic markings associated with male pores (Fig. 4c) . . Metapheretima (p. 78)Crescentic markings absent ........... 4 4 Clitellum extending over more than three segments; spermathecal diverticula multilocular Archipheretima (p. 21) Clitellum restricted to three segments, spermathecal diverticula simple . Polypheretima (p. 28) 5(2) Intestinal caecum(a) originating in or near segment xxii ..... Pithemera 1 Intestinal caecum(a) originating in or near segment xxvii ...... 6 6 Male pores simple ............ Amynthas 1 Male pores within copulatory pouches ......... 7 7 Nephridia on spermathecal ducts ........ Pheretima 1 Nephridia absent from spermathecal ducts ....... Metaphire 1 1 For keys to the nominal species and species-groups of the 'caecate' genera, Amynthas, Metaphire, Pheretima andPithemera, see Sims & Easton (1972). For species transferred to these genera since 1972 see below (p. 119). ARCHIPHERETIMA Michaelsen, 1928 Megascolex (part): Beddard, 1895 : 370. Amynthas (part): Beddard, 1900a : 612. Pheretima (part): Michaelsen, 1900 : 234. Pheretima (Archipheretima} (part) Michaelsen, 1928a : 7. Pheretima (Archipheretima): Michaelsen, 19346 : 15. Archipheretima: Sims & Easton, 1972 : 200, 232. TYPE SPECIES. Megascolex iris Michaelsen, 1892, original designation. DIAGNOSIS. Megascolecidae with an oesophageal gizzard in viii, intestinal caeca and gizzardsabsent. Body cylindrical, setae never excessively crowded ventrally, creeping sole absent. Malepores superficial or on circular porophores, never within copulatory pouches. Spermathecaldiverticula multilocular. DESCRIPTION. Body cylindrical. Clitellum annular, extending over four or more segments inmature individuals (xii, xiii-xvi, xvii, xviii). Dorsal pores present from 12/13. Setae perichaetinewith large dorsal gaps (up to 0-25 body circumference), often slightly crowded ventrally. Lateralhearts in x-xii and sometimes xiii. Oesophagus with a well-developed gizzard in viii, lacking dorsal pouches and calciferousglands. Intestine begins between xv and xvii, simple, lacking caeca, gizzards and glandular walls. Holandric, testes free (?) or in large, delicate sacs lining the coelom and usually enclosing theanterior seminal vesicles, the lateral hearts and other vessels. Seminal vesicles paired in xi and xii. Prostates racemose. Paired, combined male and prostatic pores on the ventral surface of xviiiin the setal ring. Male pores occasionally on porophores which may be elongate and extend onto 22 E. G. EASTON xix and xx. Copulatory pouches absent. Ovaries free. Oviducts leading to single or closely pairedmidventral equatorial pore(s) on xiv. Spermathecae only slightly differentiated into duct andampulla; each with a short multilocular diverticulum. Spermathecae arranged in pairs in three orfour adjacent segments between v and ix. Spermathecal pores always intersegmental, small, oftenslitlike, ventral or ventrolateral. Genital markings of two kinds have been recorded ; discrete paired, ovoid segmental markingsand diffuse intersegmental markings. The porophores extending from xviii to xx in some speciesmay be confused with genital markings. DISTRIBUTION. Borneo, Philippines. INCLUDED SPECIES, iris species-group (iris, margaritacea, mazarredi, zonatd), ophiodes, picta. NUMERICAL STUDIES. In the initial computer study (see above) the affinities of the species asrevealed by the MST and their configuration on the first and second vectors (Fig. 6) provide thebasis for the recognition of two distinct species and one species-group. REMARKS. Although a key is provided for the identification of species included in the genusArchipheretima, mature individuals may be readily assigned to their species or species-group onthe form of their genital markings (Figs 1 1 and 12). The species tumifaciens (Lee, 1967) which wasprovisionally included in Archipheretima by Sims & Easton (1972) is now transferred to Meta-pheretima as a synonym of M. jocchana (Cognetti, 1911). Key to the species of the genus Archipheretima 1 First spermathecal pores in furrow 4/5 (3 thecal segments) .... ophiodes (p. 27) First spermathecal pores in furrow 5/6 (4 thecal segments) ...... 2 First spermathecal pores in furrow 6/7 (3 thecal segments) ...... 4 2 Spermathecal pores closely paired (0-05 body circumference apart) . . . zonata (p. 23)Spermathecal pores widely paired (0-20-0-30 body circumference apart) .... 3 3 Male pore small, indistinct (Philippines) ...... mazarredi (p. 23) Male pore at centre of large porophore (Borneo) ...... picta (p. 26) 4(1) Spermathecal pores c. 0-05 body circumference apart (preclitellar genital markings absent) iris (p. 26)Spermathecal pores c. 0-10 body circumference apart (preclitellar genital markings present) margaritacea (p. 25) Archipheretima iris species-group DIAGNOSIS. Archipheretima with poorly defined intersegmental genital markings and simple malepores. DISTRIBUTION. Borneo and Philippines. SPECIES INCLUDED, iris, margaritacea, mazarredi, zonata. REMARKS. Juvenile and other individuals with poorly developed genital markings may be dis-tinguished from picta by the absence of a porophore and from ophiodes by the presence ofspermathecal pores in furrow 7/8. Marker characters of the species included in the iris species-group are given in Table 4. Archipheretima mazarredi (Rosa, 1894) Megascolex mazarredi Rosa, 1 894 : 6. Amynthas mazarredoi: Michaelsen, 1899 : 15; Beddard, 1900a : 644.Pheretima mazarredoi: Michaelsen, 1900 : 283; Gates, 1970a : 155.Archipheretima mazarredoi: Sims & Easton, 1972 : 232. DIAGNOSIS. Archipheretima with spermathecal pores about one fifth of the body circumferenceapart in furrows 5/6/7/8/9. Genital markings poorly defined, intersegmental. DESCRIPTION. External characters. Length 200-325 mm, diameter 13-15 mm. 105-131 segments.Clitellum xiii-xvi. First dorsal pore 12/13. Setae c. 100 on xxv, setal ring crowded ventrally. ACAECATE PHERETIMOID EARTHWORMSTable 4 Marker characters of the members of the Archipheretima iris species-group 23 Male pores c. 0-20 body circumference apart. Female pore single. Spermathecal pores paired,5/6/7/8/9, c. 0-20 body circumference apart. Genital markings (Fig. 11 a) diffuse, paired, intersegmental in line with the male pores in 17/18and 18/19, 19/20, 20/21. Internal characters. Septa anterior to 17/18 thickened. Intestine begins in xvii. Lateral hearts inx-xiii. Holandric, testes in x and xi, testes sacs membranous or absent, seminal vesicles in xi and xii.Spermathecae (Fig. lOa) paired in vi-ix. Description after Rosa (1894) and Gates (1970). Fig. 1 la is an interpretation of the genitalfield based on the written descriptions. 10mm Fig. 10 Spermathecae. (a) Archipheretima mazarredi; (b) A. zonata; (c) A. margaritacea;(d) A. iris; (e) A. picta. Scales 1 mm unless otherwise indicated. DISTRIBUTION. Marinduque Island, Philippines. REMARKS. The correct spelling of the name mazarredi has been the subject of confusion. Theoriginal orthography, mazarredi, was changed by Michaelsen (1900) to mazarredoi, an unjustifiedemendation (Article 33, Int. Code zool. Nomencl.) which has been used by subsequent authors. RECORDS. 1C Marinduque Island, Philippines (holotype of mazarredi). It has not been possible tolocate the holotype of this species. It is absent from the collection of the Museo Nacional deCiencias Naturales, Madrid, where Gates (1970) suggested that it may be found: Dr J. Alvarez,personal communication. 7 A Marinduque Island, Philippines (mazarredi: Gates, 1970). Archipheretima zonata (Michaelsen, 1922) Pheretima zonata Michaelsen, 1922 : 42. Pheretima (Archipheretima) zonata: Michaelsen, 1928a : 11; Michaelsen, 19346 : 15. Archipheretima zonata: Sims & Easton, 1972 : 181, 232. 24 E. G. EASTON ) ( a Fig. 11 Anterior ventral surface, diagnostic characters, (a) Archipheretima mazarredi;(b) A. zonata; (c) A. margaritacea; (d) A. iris. Pheretima (Archipheretima) penrisseni Michaelsen, 1928a : 11; Michaelsen, 19346 : 15.Archipheretina penrisseni: Sims & Easton, 1972 : 232. DIAGNOSIS. Archipheretima with spermathecal pores about one twentieth of the body circumfer-ence apart in furrows 5/6/7/8/9. Genital markings poorly defined, intersegmental. DESCRIPTION. External characters. Length 190-360 mm, diameter 10-15 mm. 124-147 segments.Clitellum \xiii-\xviii. First dorsal pore 12/13. Setae 90-94 on vii, 84-96 on xx. Setal ring slightlycrowded ventrally on preclitellar segments (aa = ab = Q-6yz = 0-6zz), and with dorsal gaps onpostclitellar segments (aa = ab = 0-6yz = Q-3zz). Male pores simple, c. 0-05 body circumference apart. Female pore single or paired. Spermathe-cal pores small, paired, 5/6/7/8/9, c. 0-04 body circumference apart. Genital markings (Fig. lib), single or paired, intersegmental in 17/18, 18/19, 19/20.Internal characters. Septa 5/6-7/8 thickened, 8/9 membranous, 9/10-13/14 thickened. Intestinebegins in xvi. Lateral hearts in x-xii. Holandric, testes sacs annular, enclosing the lateral hearts, in x and, in xi the anterior seminalvesicles as well. Spermathecae (Fig. lOb) paired in vi-ix. DISTRIBUTION. Borneo. REMARKS. Genital markings are absent from the holotype of zonata while the clitellum has notdeveloped to its full length in the holotype of penrisseni. These differences are probably attribu-table to differential rates of achieving maturity. ACAECATE PHERETIMOID EARTHWORMS 25 a b Fig. 12 Anterior ventral surface, diagnostic characters, (a) Archipheretima ophiodies; (b) A. picta. MATERIAL EXAMINED. 1C Nangaraun, Kalimanton; Leiden 1816 (holotype of zonata). 1C MtPenrissen, Sarawak; Hamburg v 105 13 (holotype of penrisseni). Archipheretima margaritacea (Michaelsen, 1892) Megascolex margaritacea Michaelsen, 1892 : 245; Beddard, 1895 : 383.Amynthas margaritacea: Michaelsen, 1899 : 16; Beddard, 1900a : 647.Pheretima margaritacea: Michaelsen, 1900 : 282.Pheretima (Archipheretima) margaritacea: Michaelsen, 19346 : 15.Archipheretima margaritacea: Sims & Easton, 1972 : 232. DIAGNOSIS. Archipheretima with spermathecal pores about one tenth of the body circumferenceapart in furrows 6/7/8/9. Genital markings poorly denned, intersegmental in furrows 9/10, 10/11,12/13 and in postclitellar furrows. DESCRIPTION. External characters. Length c. 90 mm, diameter c. 5 mm. 85-103 segments. Clitellum\xiUr^xvii. First dorsal pore 12/13. Setae, c. 28 on vii, c. 28 on xx, setal ring regular on preclitellarsegments with dorsal and ventral gaps (aa = 2ab = 2yz = 0'5zz), slightly crowded ventrally withdorsal and ventral gaps on postclitellar segments (aa = 2ab=yz = Q-5zz). Male pores simple, c. 0-10 body circumference apart. Female pores paired. Spermathecal poressmall transverse slits, 6/7/8/9, c. 0-10 body circumference apart. Genital markings (Fig. lie), diffuse, unpaired, median, intersegmental in 10/11, 17/18, 18/19,19/20 and occasionally 9/10 and 12/13. 26 E. G. EASTON Internal characters. Not known. Spermathecae (Fig. lOc) paired in vii-ix.DISTRIBUTION. Samar Island, Philippines. REMARKS. Michaelsen (1892) did not describe the internal morphology of this species. All theinternal structures in the anterior region except the spermathecae have been removed from thesurviving syntype by previous dissection. It is probable that the internal anatomy of this speciesresembles that of iris. MATERIAL EXAMINED. 1A (lacking anterior portions of gut and anterior male reproductive organs)Loquilocon, Samar Island, Philippines; Hamburg v361 (syntype of margaritaced). OTHER MATERIAL. Data as above; Berlin 2134 (syntype(s) of margaritaced). This material couldnot be located during the preparation of this report: Dr G. Hartwich, personal communication. Archipheretima iris (Michaelsen, 1 892) Megascolex iris Michaelsen, 1892 : 244; Beddard, 1895 : 383. Amynthas iris: Michaelsen, 1899 : 15; Beddard, 1900a : 647. Pheretima iris: Michaelsen, 1900 : 276. Pheretima (Archipheretima) iris: Michaelsen, 1928a : 8; Michaelsen, 19346 : 15. Archipheretima iris: Sims & Easton, 1972 : 200, 232. DIAGNOSIS. Archipheretima with spermathecal pores about one twentieth of the body circum-ference apart in furrows 6/7/8/9. Genital markings poorly defined, intersegmental in postclitellarfurrows only. DESCRIPTION. External characters. Length 170-240 mm, diameter 7-9 mm. 110-116 segments.Clitellum xiii-\xvii. First dorsal pore 12/13. Setae, 34-40 on vii, 42-46 on xx, setal ring slightlycrowded ventrally with dorsal and ventral gaps (aa = 2ab=yz = Q-25zz). Male pores simple, c. 0-05 body circumference apart. Female pore single. Spermathecal porespaired, small transverse slits, 6/7/8/9, c. 0-05 body circumference apart. Genital markings (Fig. lid) diffuse unpaired, median, intersegmental in 17/18, 18/19, 19/20,20/21. Internal characters. Septa 6/7-12/13 membranous. Intestine begins in xvii. Lateral hearts inx-xiii. Holandric, testes sacs large, annular in x and xi, enclosing the lateral hearts and in xi the seminalvesicles as well, seminal vesicles small, extending to the lateral line. Spermathecae (Fig. lOd)paired vii-ix. DISTRIBUTION. Samar Island, Philippines. REMARKS. The description differs in some details from those of earlier authors (Michaelsen, 1892;Sims & Easton, 1972). Michaelsen recorded the number of segments in this species as 240, neitherof the clitellate specimens examined had more than 116 segments, but both approached the maxi-mum length of 240 mm recorded by Michaelsen. Sims and Easton recorded the separation of themale and spermathecal pores as 0-25 but an examination of the type series confirmed that thevalue should be 0-05 as contained in the original description. MATERIAL EXAMINED. 2C, 2A Loquilocon, Samar Island, Philippines; Berlin 565 (syntypes of iris).1A Data as above; Turin 01 122 (syntype of iris). Archipheretima picta (Michaelsen, 1892) Megascolex pictus Michaelsen, 1892 : 246; Beddard, 1895 : 384. Amynthas pictus: Michaelsen, 1899 : 83; Beddard, 1900a : 623. Pheretima picta: Michaelsen, 1900 : 294. Pheretima (Archipheretima) picta: Michaelsen, 1928a : 10; Michaelsen, 19346 : 15. Archipheretima picta: Sims & Easton, 1972 : 230. ACAECATE PHERETIMOID EARTHWORMS 27 Pheretima beccarii Cognetti, 1909 : 331. Pheretima (Archipheretima) beccarii: Michaelsen, 1928a : 11. Archipheretima beccarii: Sims & Easton, 1972 : 230. DIAGNOSIS. Archipheretima with spermathecal pores about one quarter of the body circumferenceapart in furrows 5/6/7/8/9. Male pores on circular porophores. Genital markings ovoid, paired,presetal on vi-ix and xviii. DESCRIPTION. External characters. Length 240-260 mm, diameter, 5-9 mm. 137-146 segments.Clitellum xiii-^xviii. First dorsal pore 12/13. Setae, c. 74 on vii, c. 77 on xx, setal ring regularwith dorsal gaps on preclitellar segments (aa = ab=yz = 0-3zz), slightly crowded ventrally withdorsal and ventral gaps on postclitellar segments (aa = 2ab=yz = Q-3zz). Male pores on circular porophores c. 0-29 body circumference apart. Female pore single.Spermathecal pores small in 5/6/7/8/9 c. 0-27 body circumference apart. Genital markings (Fig. 12b) paired, presetal, in line with the spermathecal pores, on vi-ix,anterior to the male pores on xviii. Internal characters. Septa 5/6/7/8 slightly thickened, 8/9 absent, 9/10-13/14 slightly thickened.Intestine begins in xv. Lateral hearts in x-xiii. Holandric, testes sacs annular in x and xi, seminal vesicles large, extending to the dorsal linein xi and xii, those of xi enclosed in the posterior testes sacs. Spermathecae (Fig. lOe) paired invi-xi. DISTRIBUTION. Borneo. REMARKS. The original description of picta did not contain details of the genital markings ormention of intestinal caeca. Later Michaelsen (1900 : 248) was uncertain whether picta possess-ed intestinal caeca, although finally he included it in the subgenus Archipheretima (1928 : 10).In the absence of typical material, it is proposed to accept Michaelsen's decision since the othercharacters he listed, length of clitellum and form of spermathecal diverticula, support the inclusionof the species in Archipheretima. The holotype of beccarii agrees closely with the description of picta, being distinguishable onlyby a shorter clitellum and the presence of genital markings. These differences are probablyattributable to varying stages of development. MATERIAL EXAMINED. 1C Sarawak; Geneva 44045 (holotype of beccarii). OTHER RECORDS. 1C Sampit, Kalimanton; Berlin 554 (holotype of picta). This specimen is listedin the catalogue of the Berlin Museum but it could not be located during the preparation of thispaper: Dr G. Hartwich, personal communication. Archipheretima ophiodes (Michaelsen, 1929) Pheretima (Archipheretima) ophiodes Michaelsen, 1929:85; Michaelsen, 1930a:273; Michaelsen, 19346 : 15.Archipheretima ophiodes: Sims & Easton, 1972 : 230. DIAGNOSIS. Archipheretima with spermathecal pores in furrows 4/5/6/7. Male pores on raisedporophores extending from xviii to xx. DESCRIPTION. External characters. Length 245-300 mm, diameter 13-20 mm. 106-118 segments.Clitellum xii-xvii. First dorsal pore 12/13. Setae, c. 60 on vii, c. 67 on xxvi, c. 72 on xxx, setal ringcrowded ventrally with very large dorsal gaps (zz = 0-25 body circumference). Male pores simple, on raised porophores extending from xviii to xx (Fig. 12a), separation notrecorded. Female pores paired. Spermathecal pores in 4/5/6/7, c. 0-33 body circumference apart. Genital markings absent. Internal characters. All anterior septa present and delicate. Beginning of intestine not recorded.Lateral hearts in x-xiii. 28 E. G. EASTON Holandric, testes sacs in x and xi, details not recorded. Seminal vesicles in xi and xii, simple,thin. Spermathecae paired in v-vii, ampulla sack-like or pear-shaped, not differentiated intoampulla and duct, diverticula small, globular. Description after Michaelsen (1929, 1930); and the author after the examination of the remainsof a syntype. DISTRIBUTION. Luzon, Philippines. MATERIAL EXAMINED. The gizzard, oesophagus, part of the intestine and part of the anterior malereproductive system (the body wall has not survived). Mt Azapan, Luzon, Philippines ; Hamburgv 104 18 (remains of syntype of ophiodes), POLYPHERETIMA Michaelsen, 1934 Megascolex (Perrierd) (part) Vaillant, 1889 : 63. Perichaeta (part): Beddard, 1895 : 388. Amynthas (part): Beddard, 1900a : 612. Pheretima (part): Michaelsen, 1900 : 234. Pheretima (Parapheretimd) (part) Cognetti, 1912 : 556; Michaelsen, 1928a : 8. Pheretima (Pheretima) (part): Michaelsen, 1928a : 8. Pheretima (Metapheretima) (part): Michaelsen, 1928a : 8. Metapheretima (part): Sims & Easton, 1972 : 205, 233. Pheretima (Polypheretima) (part) Michaelsen, 19346 : 15. TYPE SPECIES. Perichaeta stelleri Michaelsen, 1892, original designation. DIAGNOSIS. Megascolecidae with an oesophageal gizzard in viii, intestinal caeca and gizzardsabsent. Body cylindrical, setae never excessively crowded ventrally, creeping sole absent. Malepores on circular porophores which may be within copulatory pouches. Crescentic genital markingsabsent. Spermathecal pores small, spermathecal diverticula simple and usually ectal in origin. DESCRIPTION. Body cylindrical, creeping sole absent. Clitellum annular, restricted to threesegments (xiv-xvi). First dorsal pore between 5/6 and 12/13. Setae perichaetine, never excessivelycrowded ventrally, dorsal and ventral gaps small (aa= \-2ab, zz= \-2yz). Lateral hearts in x-xiiand sometimes xiii. Oesophagus with a well-developed gizzard in viii but lacking calciferous glands and dorsalpouches. Intestine begins in xv or xvi, simple, lacking caeca, gizzards and glandular walls. Usually holandric, occasionally metandric, ? never proandric - testes may be restricted to xin sibogae which is known only from the damaged holotype. The testes of each segment are en-closed in single or paired stout sacs which usually occupy most of the coelom and often enclosethe anterior seminal vesicles and the lateral hearts of x and xi. One pair of seminal vesicles in thesegment directly posterior to each pair of testes. Prostates racemose. Paired combined male andprostatic pores on the ventral surface of xviii in the setal ring. Male pores situated on circularporophores, often within copulatory pouches. The porophores bearing the male pores are shortand stout (cf. penial bodies in Metapheretima} while the openings to the copulatory pouches,when present, are often crescentic (Figs 3a-f). Ovaries free in xiii. Oviducts lead to single or closelypaired, mid ventral, equatorial pore(s) on xiv. Spermathecae each differentiated into duct andampulla, diverticula simple and ectal in origin, usually as long or longer than main duct andampulla. Spermathecae arranged in pairs or paired batteries of up to 28 Spermathecae, in one tofive adjacent segments between v and ix. Spermathecal pores small, usually intersegmental, rarelysegmental. Genital markings always of the discrete type, diffuse genital markings and annular ridgesabsent. When present on xviii the genital markings are identical to those of adjacent segments;they are never crescentic and closely associated with the male pores. The arrangement of genitalmarkings is variable. The glandular tissue associated with the genital markings may be restrictedto the body wall or invade the coelom in the form of stalked glands. The area around the malepores may be infrequently elevated above the body surface. ACAECATE PHERETIMOID EARTHWORMS 29 66 61 60'63* '52 Fig. 13 Principal co-ordinates analysis of 35 species here assigned to Polypheretima (37-71 ofTable 1): the configuration of species with the vectors corresponding to the first and secondlatent roots. The linkages of the added MST are graded to indicate percentage similarities; , +95%; , 90-95%; , -90%. Three major assemblages are recognized: Division I - circular and star-shaped symbols (closed circles - bifaria species-group, open circle - grata, closed stars - annulata species-complex, open star - voeltzkowi).Division II - triangular symbols (polytheca species-group). Division III -square symbols (closed squares -badia species-group, open squares -pataespecies-group). DISTRIBUTION. (Fig. 8.) Autochthonous species have been recorded throughout the Pheretimagroup domain except from New Britain, the Solomon Islands, New Hebrides, Caroline Islandsand Marianas. NUMERICAL STUDIES. The taxa of the genus Polypheretima listed in Table 1 (37-71) were subjectedto a numerical analysis utilizing the characters listed in Table 2. The configuration of the taxawith the first and second vectors of the principal co-ordinates analysis as axes, to which the MSTwith graded linkages has been added, is shown in Fig. 13. Three divisions, indicated by circular,triangular and square symbols, may be recognized. The division to which the species pentacystis(61) should be assigned requires discussion. From its position on the first and second vectors itwould appear to belong to Division II (triangular symbols), although it is linked by the MST toDivision I (circular symbols). Since this species possesses several characters diagnostic of DivisionII as well as having several nearest neighbours among the taxa of this division, it is proposed toinclude pentacystis in Division II. Morphologically the three divisions are readily defined. All holandric taxa are accommodatedin Divisions I and II while metandric species form Division III (square symbols). With the excep-tion of the species grata (50) all the members of Division I have simple male pores while those of 30 E. G. E ASTON Division II have male pores within copulatory pouches. The copulatory pouches of grata differfrom those of members of Division II in that stalked glands discharge into them in addition to themale pores. An examination of all of the vectors available for study failed to reveal the presence of sub-ordinate clusters within Division I. Nevertheless it is convenient to recognize a species group, aspecies-complex and two species within this division. The individual species are grata (50) dis-cussed above and voeltzkowi (51) with postsetal spermathecal pores. The members of the annulataspecies complex, annulata (37) and fakfakensis (38), have presetal spermathecal pores. Thebifaria species-group is recognized by the possession of simple male pores and intersegmentalspermathecal pores. All of the taxa in Division II are assigned to thepolytheca species-group. Included in this species-group are taxa 54-58 the elongata species-complex which are linked by the MST at very highlevels. Table 5 Phenetic classification and checklist of the genus Polypheretima DIVISION I bifaria species- group DIVISION II- wlytheca species-group- DIVISION III- badia species-group- patae species-group- -annulataspecies-complex - bifaria (39)brevis (40)fida (41)gatesi (42)iizukai (43)mertoni (44)moellerimonticola (45)panarana (46)sempolensis (47)sepikensis (48)taprobaenae (49) grata (50)voeltzkowi (51) annamensis (52)aringeana (53) elongataspecies-complex koyana (59)lesonea (60)pentacystis (61)polytheca (62)renschi (63) badia (64)elberti (65)kellneri (66)sibogae (68)swelaensis (67) coplandi (69)huonensiskershawae (70)patae (71) f annulata (37)(fakfakensis (38) elongata (54)everetti (55)kinabaluensis (56)phacellotheca (57)m stelleri (58) Numbers in parentheses indicate taxa assessed in numerical studies (see Figs 6 and 1 3). ACAECATE PHERETIMOID EARTHWORMS 31 The taxa forming Division III can be readily divided into two clusters, indicated by open andclosed square symbols, on the position of the species along the third vector (not shown here) andby application of the MST. The cluster indicated by solid square symbols, the badia species-group,comprises taxa from the Lesser Sunda Islands, these have a single pair of genital markings on eachof several postclitellar segments. While the clusters indicated by open square symbols, the pataespecies-group, contains taxa from New Guinea with numerous genital markings arranged intransverse rows on several postclitellar segments. A summary of the phenetic classification based on this numerical investigation is given inTable 5. Key to the species of the genus Polypheretima 1 Proandric ............ sibogae 1 (P- 58) Holandric 2 Metandric .............. 21 2 Male pores simple ............. 3 Male pores in copulatory pouches .......... 1 3 3 Spermathecal pores segmental 4 Spermathecal pores intersegmental .......... 5 4 Spermathecal pores presetal (vii, viii or vii, viii, ix) 2 . . annulata species-complex (p. 34)Spermathecal pores postsetal (v only) ...... voeltzkowi (p. 47) 5(3) First Spermathecal pores in furrow 4/5 ......... 6 First Spermathecal pores in furrow 5/6 7 First Spermathecal pores in furrow 6/7 ......... 12 First Spermathecal pores in furrow 7/8 (one thecal segment) 3 . . taprobanae (p. 45) 6 Two or three thecal segments 4 ......... fida (p. 37) Five thecal segments moelleri (p. 38) 7(5) Two thecal segments 8 Three thecal segments ............ 10 Four thecal segments 5 ............ 1 1 8 One pair of genital markings per segment (Java) .... sempolensis (p. 39)Two or more pairs of genital markings per segment (New Guinea area) ... 9 9 Glands to genital markings confined to body wall .... mertoni (p. 40)Glands to genital markings stalked, occupy coelom .... seplkensis (p. 40) 10(7) Bithecal 6 brevis (p. 41) Poly thecal bifaria (part) (p. 41) 11(7) Genital markings presetal only (Philippines) monticola (p. 42) Genital markings pre- and postsetal (New Guinea) .... bifaria (part) (p. 41) Genital markings postsetal only (Japan) iizukai (p. 43) 12(5) Spermathecal pores c. 0-3 body circumference apart (genital markings as fig. 20b) panarana (p. 45)[ Spermathecal pores c. 0-5 body circumference apart (genital markings as fig. 20a) gatesi (p. 44) 13 First Spermathecal pores in furrow 4/5 (five thecal segments) . . pentacystis (p. 48)First Spermathecal pores in furrow 5/6 ......... 14 First Spermathecal pores in furrow 6/7 ......... 19 First Spermathecal pores in furrow 7/8 (two thecal segments) . . . renschi (p. 56) 14 One or two thecal segments ........... Four thecal segments ....... .... 17 15 Stalked glands discharge into copulatory pouches; external postclitellar genital markings absent grata (p. 46) Copulatory pouches lack stalked glands; external postclitellar genital markings present. 16 16 Postclitellar genital markings simple, presetal; Spermathecal pores c. 0-25 body circum- ference apart elongata species-complex (part) (p. 52) Postclitellar genital markings complex, occupying whole length of segment; Spermathecal pores c. 0-50 body circumference apart aringeana (p. 55) 17(14) Spermathecal batteries with 6-10 spermathecae in each (Malaya and Borneo) . . 18Spermathecal batteries with 1 spermatheca in 5/6/7/8, 8-10 in 8/9 (Sumatra) lesonea (part) (p. 51) 3218 E. G. E ASTON Male pores c. 0-17 body circumference apart (Borneo)Male pores c. 0-24 body circumference apart (Malaya) 19(13) One thecal segment Three thecal segments ....... 20 Spermathecal batteries with 1 spermatheca in each (Vietnam) koyana (p. 50) polytheca (p. 49) 20 lesonea (part) (p. 51)annamensis (p. 56) Spermathecal batteries with more than 1 spermatheca in each (Indonesia) elongata species-complex (part) (p. 52)21(1) Papuan specimens ............. 22 Specimens from the Lesser Sunda Islands ......... 23 22 Two thecal segments (vi-vii); Spermathecal pores c. 0-33 body circumference apart huonensis (p. 63)Three thecal segments (v-vii); Spermathecal pores c. 0-42 body circumference apart coplandi (p. 62)Four thecal segments (v-viii); Spermathecal pores c. 0-26 body circumference apart kershawae (p. 62)Five thecal segments (v-ix); Spermathecal pores c. 0-55 body circumference apart patae (p. 61) 23(21) First Spermathecal pores in furrow 4/5 24 First Spermathecal pores in furrow 5/6 7 26 m Fig. 14 Spermathecae. (a) Polypheretima annulata; (b) P. fida; (c) P. moelleri; (d) P. sempolensissp. nov.; (e) P. mertoni; (f) P. sepikensis; (g) P. brevis; (h) P. bifaria; (i) P. izzukai; (j) P. gatesisp. nov.; (k) P. panarana; (1) P. taprobanae; (m) P. grata; (n) P. veoltzkom. All scales 0-5 mmunless otherwise indicated. ACAECATE PHERETIMOID EARTHWORMS 24 Bithecal Polythecal 25 Spermathecal pores c. 0-3 body circumference apart .Spermathecal pores c. 0-5 body circumference apart . 26(23) Three thecal segments Four thecal segments ....... 27 Spermathecal pores c. 0-3 body circumference apart . Spermathecal pores c. 0-5 body circumference apart . 33 25 sibogae 1 (p. 58) badia (part) (p. 59) kellneri (p. 57) swelaensis (p. 60) 27 badia (part) (p. 59)elberti (p. 60) 1 It is uncertain whether the unique type of P. sibogae is proandric or metandric. This species has therefore beenkeyed out to allow for either condition. 2 Pheretima cupreae Chen, 1946 (species incertae sedis) will also emerge at this dichotomy. It may be distinguishedfrom annulata by the arrangement of its genital markings (the distribution of this taxon is also different). 3 Pheretima touranensis Michaelsen, 1934c (species incertae sedis) will key put at this point. It may be distinguishedfrom taprobanae by the possession of two pairs of spermathecal pores (in furrows 7/8/9). 4 Planapheretima subulata closely resembles some species of Polypheretima, especially in the form of the genitalmarkings and male pores, so it has been included here to aid differentiation. 5 Archipheretima picta will key out at this point. The male pores and genital markings of this species closely resemblethose of Polypheretima, and confusion may occur when dealing with individuals lacking fully developed clitellaand spermathecal diverticula. 6 Pheretima flabellifera Cognetti, 1911 (species incertae sedis) will key out at this point. It may be distinguishedfrom brevis only by the possession of genital markings and small testes sacs. 7 Although Polypheretima badia is diagnosed as possessing spermathecal pores in furrows 5/6/7/8/9 and occasionally4/5, there are discrepancies between the type series and the original description. The latter reported individualswith spermathecal pores in furrows 6/7/8/9 only, such individuals will emerge at this dichotomy. Fig. 15 Spermathecae. (a) Polypheretima pentacystis; (b) P. polytheca; (c) P. koyana; (d) P. lesoneasp. nov.; (e) P. everetti; (f) P. aringeana; (g) P. annamensis; (h) P. sibogae; (i) P. elberti; (j) P.swelaensis; (k) P. patae sp. nov. ; (1) P. coplandi sp. nov. ; (m) P. kershawae sp. nov. ; (n) P. huonensissp. nov. All scales 0-5 mm. 34 E. G. EASTON Polypheretima annulata species-complex DIAGNOSIS. Polypheretima with simple male pores; paired presetal spermathecal pores on vii andviii or vii, viii and ix. DESCRIPTION. External characters. Length 58-195 mm, diameter 3-7 mm. 56-146 segments.Clitellum xiv-xvi. First dorsal pore 10/11-13/14. Setae, 45-72 on vii, 50-90 on xx, setal ringregular (aa = ab=yz = zz). Male pores on small porophores 0-25-0-28 body circumference apart. Female pore single.Spermathecal pores paired, presetal on vii and viii or vii, viii and ix, 0-45-0-50 body circumferenceapart. Genital markings (Fig. 17a), small, paired, postsetal on vii, viii, ix, two pairs of presetal and twopairs of postsetal markings on xvii-xix, lateral pairs slightly median to the line of the male pores.Internal characters. Septa 5/6/7/8 thickened, 8/9 membranous or slightly thickened, 9/10-12/13thickened. Intestine begins in xv. Lateral hearts in x-xiii. Holandric, testes sacs paired, extending to the dorsal line in x and xi, seminal vesicles small inxi and xii, pseudoseminal vesicles in xiii, large. Spermathecae (Fig. 14a) paired in vii-viii or vii-ix. DISTRIBUTION. (Fig. 16.) West and southwest New Guinea and the islands to the southwest. REMARKS. The P. annulata species-complex is readily recognized by the segmental position of thespermathecal pores. Only one other species of this genus, voeltzkowi, has segmental spermathecalpores but they are postsetal on v. Fig. 16 Polypheretima annulata species complex: geographical distribution of the component species. ACAECATE PHERETIMOID EARTHWORMS 35 The two species included are separable on the number of pairs of spermathecae :P. annulata, characterized by the presence of spermathecae opening onto vii and viii, occurs inthe south-eastern part of the range of the species-complex while P.fakfakensis with spermathecaeopening onto vii, viii and ix, occurs in the northwestern portion of the range. The close affinity of these two species was first recognized by Michaelsen (1910a) when he de-scribed fakfakensis tetratheca, which is here included in the synonymy of annulata together withkochii and its synonyms invisa and schaedleri (Michaelsen, 1938). Polypheretima annulata (Horst, 1883) Megascolex annulatus Horst, 1883 : 195. Perichaeta annulata: Horst, 1890 : 236; Horst, 1893 : 29; Beddard, 1895 : 426. Amynthas annulatus: Beddard, 1900a : 634. Pheretima annulata: Michaelsen, 1900 : 253. Metapheretima annulata: Sims & Easton, 1972 : 233. Pheretima fakfakensis tetratheca Michaelsen, 1910a : 254; Michaelsen, 1922 : 53; Michaelsen, 19306 : 13; Gates, 19366 : 385. Metapheretima fakfakensis tetratheca: Sims & Easton, 1972 : 233.Pheretima kochii Cognetti, 1913 : 293. Pheretima (Pheretima) kochii: (syn. invisa, schaedleri) Michaelsen, 1938 : 167.Metapheretima kochii: Sims & Easton, 1972 : 233.Pheretima invisa Cognetti, 1913 : 294. ['"& "\ / _ 1 "O- "A*, A&'-O" Fig. 17 Anterior ventral surface, diagnostic characters, (a) Polypheretima annulata;(b) P. voeltzkowi, arrows indicate dorsal postsetal spermathecal pores; (c) P. grata. 36 E. G. EASTON Metapheretima invisa: Sims & Easton, 1972 : 233.Pheretima schaedleri Michaelsen, 1922 : 52.Metapheretima schaedleri: Sims & Easton, 1972 : 233. DIAGNOSIS. P. annulata species-complex with spermathecal pores on segments vii and viii.DISTRIBUTION. Southwest New Guinea, Kepulauan Banda, Kepulauan Kai, Kepulauan Aru. MATERIAL EXAMINED. 2C 'Indonesia'; Leiden 1855 (syntypes of annulata). 4C Gt Kai, KepulauanKai; Hamburg v3032 (syntypes of fakfakensis tetratheca). 1C Gt Kai, Kepulauan Kai; BogorAnn058 (fakfakensis tetratheca: Gates, 1936). 2C, 1A Etna Bay, West Irian; Amsterdam Vol. 275(syntypes of kochii). 1C Bivak Island, West Irian; Hamburg vl 1729 (kochii: Michaelsen, 1938,other specimens of this series, Amsterdam Vol. 278, were not examined). 1C Sabang, West Irian;Amsterdam Vol. 270 (syntype of invisa). 1C Skroe, West Irian; Leiden 1822 (holotype of schraed-leri). OTHER RECORDS. Wammer Island, Kepulauan Aru (syntype(s) of fakfakensis tetratheca). KobroorIsland, Kepulauan Aru (syntype(s) of fakfakensis tetratheca). Dobo, Kepulauan Aru; Leiden1815 (fakfakensis tetratheca: Michaelsen, 1922). Kepulauan Aru (fakfakensis tetratheca: Michael-sen 1930). Near river Lorentz, West Irian (syntype of kochii). Bivak Island and north of riverLorentz, West Irian (syntypes of invisa). Polypheretima fakfakensis (Cognetti, 1908) Pheretima fakfakensis Cognetti, 1908 : 1. Pheretima (Pheretima) fakfakensis: Michaelsen, 19306 : 12. Metapheretima fakfakensis: Sims & Easton, 1972 : 233. DIAGNOSIS. P. annulata species-complex with spermathecal pores on segments vii, viii and ix.DISTRIBUTION. Western New Guinea; Misool Island. REMARKS. Preclitellar genital markings are present on viii and ix (vii and viii in P. annulata) in thespecimens examined. MATERIAL EXAMINED. Previously reported. 2C Fakfak, West Irian; BMNH 1908.5.12.1-2 (syn-types of fakfakensis). 1C Misool Islands, West Irian; Hamburg vl!638 (fakfakensis: Michaelsen,1930, reported from a long series but the present location of the other individuals in unknown).New record. 2C, 1A Vogelkop, West Irian; Leiden. Polypheretima bifaria species-groupDIAGNOSIS. Polypheretima with simple male pores ; intersegmental spermathecal pores. Holandric. DISTRIBUTION. Indigenous species occur throughout the Pheretima domain. Three species, brevis,fida and taprobanae, are known only from localities to which they are suspected of being intro-duced. SPECIES INCLUDED, bifaria, brevis, fida, gatesi, iizukai, mertoni, moelleri, monticola, panarana,sempolensis, sepikensis, taprobanae. REMARKS. Several morphological trends may be detected among the species assigned to thisgroup. The Asian representatives have only a single pair of genital markings on each of severalsegments while those from the Papuan region have more numerous genital markings restrictedto one or two segments near the male pores (see also annulata species-complex and the pataespecies-group). The glands associated with the genital markings in all Asian and most Papuanspecies are restricted to the body wall but those of species from the north eastern part of NewGuinea are stalked and conspicuous (see also the Papuan species grata). This species-group isproposed for convenience of identification. Marker characters of the species included in the bifaria species-group are given in Table 6. ACAECATE PHERETIMOID EARTHWORMSTable 6 Marker characters of the members of the Polypheretima bifaria species-group 37 brevisbifaria monticolaiizukaigatesipanarana 5/6/7/8 5/6/7/8 or5/6/7/8/9 5/6/7/8/95/6/7/8/96/76/7 taprobanae 7/8 0-53 ? 0-33 (polythecal) 2 pairs pre- and postsetalxviii, 1 pair xvii, xix(Fig. 19a) ? 1 pair presetal, xvii, xix-xx (Fig. 19b) ? 1 pair postsetal xix-xxiii (Fig. 19c) 0-51 numerous, random on xviii (Fig. 20a) 0-30 numerous in clusters round c? pores stalkedglands present (Fig. 20b) 0-50 1 pair presetal xix-xxii (Fig. 20c) ? Christmas Island(Indian Ocean) North westNew Guinea Philippines Japan East New Guinea West New Guinea Polypheretima fida (Michaelsen, 1913) Pheretimafida Michaelsen, 19136 : 259.Metapheretima fida: Sims & Easton, 1972 : 233. DIAGNOSIS. Polypheretima with simple male pores ; spermathecal pores in furrows 4/5/6 and occa-sionally 6/7. Holandric. DESCRIPTION. External characters. Length 40-60 mm, diameter 4-5 mm. 93-98 segments. Clitel-lum xiv-\xvi. First dorsal pore 10/11. Setae, 40-50 on vii and xx, setal ring regular with ventralgaps (aa=l-5ab=l-5yz=l'5zz). Male pores on circular porophores, occasionally slightly invaginated, c. 0-30 body circum-ference apart. Female pores paired. Spermathecal pores paired, intersegmental in 4/5/6 and occa-sionally 6/7, c. 0-50 body circumference apart. Genital markings (Fig. 18a) simple, paired, presetal on xi-xiii slightly median to the line of thespermathecal pores, pre and postsetal on xvii and xix in line with the male pores.Internal characters. Septa 4/5-6/7 thickened, 7/8-8/9 absent, 9/10-11/12 thickened. Intestinebegins in XD. Lateral hearts in x-xii. 38 E. G. E ASTON .;.'. ^r TQ~7 Fig. 18 bed Anterior ventral surface, diagnostic characters, (a) Polypheretima fida;(b) P. sempolensis sp. nov. ; (c) P. mertoni; (d) P. sepikensis. Holandric, testes sacs annular in jc and xi, enclosing the lateral hearts and in xi the seminalvesicles, seminal vesicles large, reaching the dorsal line in xi and xii. Pseudoseminal vesicles absent.Spermathecae (Fig. 14b) paired in v, vi, and occasionally in vii. DISTRIBUTION. Loyalty Islands. REMARKS. The only record offida is based on the type series collected in the Loyalty Islands whichare only tentatively included within the Pheretima domain (see above). As the five other representa-tives which have been recorded from the Loyalty Islands and nearby New Caledonia (Amynthasdiffringens, A. rodericensis, A. taitensis, Pheretima montana and Polypheretima elongatd) are allperegrine species (Michaelsen, 19136) the occurrence offida in this area is also probably the resultof introduction by man. Possible evidence forfida being indigenous in this area is its low affinities(see numerical studies) with other species of the bifaria species-group. MATERIAL EXAMINED. 5C Lifu, Loyalty Islands; Hamburg v8067 (syntypes offida). 4C Uvea,Loyalty Islands; Hamburg v8068 (syntypes offida). Polypheretima moelleri (Michaelsen, 1921) Pheretima molleri Michaelsen, 1921 : 12.Metapheretima moelleri: Sims & Easton, 1972 : 233. DIAGNOSIS. Polypheretima with simple male pores; paired spermathecal pores in furrows 4/5/6/7/8/9. Holandric. ACAECATE PHERETIMOID EARTHWORMS 39 a b c Fig. 19 Anterior ventral surface, diagnostic characters, (a) Polypheretima bifaria;(b) P. monticola; (c) P. iizukai. DESCRIPTION. External characters. Length over 24mm, diameter c. 1-3 mm. Over 41 segments.(The unique holotype lacks a posterior portion.) Clitellum xiv-xvi. First dorsal pore 12/13. Setae,c. 24 on //, c. 30 on ///', c. 40 on viii, c. 36 on xxvi, setal ring with ventral gaps (aa=l-l-3ab). Male pores simple, on large hemispherical porophores, c. 0-40 body circumference apart.Female pore(s) not recorded. Spermathecal pores paired, intersegmental in 4/5/6/7/8/9, separationnot recorded. Genital markings absent. Internal characters. Anterior septa delicate, 7/8 absent. Beginning of intestine not recorded. Lateralhearts not recorded. Holandric, testes sacs large, paired in x and xi, seminal vesicles in xi and xii. Spermathecae(Fig. 14c) paired in v-ix. Description after Michaelsen (1921). DISTRIBUTION. Java. REMARKS. It has not been possible to locate any examples of this species and moelleri is only tentatively assigned to Polypheretima in the absence of any of the characteristics diagnostic of other acaecate genera (none of which has been recorded from Java). RECORDS. 1C (incomplete) Sand Bay, south coast of Java (holotype of moelleri). Polypheretima sempolensis sp. nov. DIAGNOSIS. Polypheretima with simple male pores; paired spermathecal pores in furrows 5/6/7.Holandric. Postclitellar genital markings simple, postsetal on AT//, presetal on xix. 40 E. G. EASTON DESCRIPTION. External characters. Length 50-62 mm, diameter c. 2 mm. 100-107 segments.Clitellum xiv-xvi. First dorsal pore 13/14. Setae, c. 60-66 on vii, 44-48 on xx, setal ring regular(aa = ab=yz = zz). Male pores simple on porophores, c. 0-33 body circumference apart. Female pore single. Sper-mathecal pores paired, intersegmental in 5/6/7, c. 0-33 body circumference apart. Genital markings (Fig. 18b) simple paired, presetal on ix, xii and occasionally xiii, median tothe line of the spermathecal pores, postsetal on xvii, presetal on xix and occasionally xx, medianto the line of the male pores. The genital markings are exceptionally large, invading the setallines and the intersegmental furrows. Internal characters. Septa 5/6-7/8 thickened, 8/9/10 membranous, 10/11-12/13 thickened. Intes-tine begins in xv. Lateral hearts in x-xii. Holandric, testes sacs on x separated ventrally but linked dorsally, that of xi annular and en-closing the anterior seminal vesicles, seminal vesicles slim, elongate, reaching the dorsal line in xiand xii, pseudoseminal vesicles small in xiv. Spermathecae (Fig. 14d) paired in vi and vii. DISTRIBUTION. East Java, 1400-1 500m. MATERIAL EXAMINED. 3C Primary forest with rich black soil tending to be rather dry, on top ofridge of ancient crater wall, Sempol Crater, East Java, 8 03' S, 114 12' E, 1500 m, coll G ALincoln 29 Jul 1973 British University Dragon Expedition; BMNH 1975.7.48-50 (syntypes ofsempolensis). 1 1C, 7A Loose black soil in middle of coffee plantation, plateau of Gunung Raung,Sempol, East Java, 1400 m, collG A Lincoln 27 Jul 1973 British University Dragon Expedition;BMNH 1975.7.28^7. Polypheretima mertoni (Michaelsen, 1910) Pheretima mertoni Michaelsen, 1910a : 256.Metapheretima mertoni: Sims & Easton, 1972 : 233. DIAGNOSIS. Polypheretima with simple male pores; paired spermathecal pores about two fifths ofthe body circumference apart in furrows 5/6/7. Holandric. Postclitellar genital markings singlepresetal median and paired, pre- and postsetal close to the line of the male pores. DESCRIPTION. External characters. Length 36-58 mm, diameter 2-2-5 mm. 76-82 segments. Clitel-lum xiv-xvi. First dorsal pore 12/13 or 13/14. Setae, c. 44 on vii t c. 40 on xx, setal ring regular(aa = ab=yz = zz). Male pores simple c. 0-30 body circumference apart. Female pore single. Spermathecal porespaired, intersegmental in 5/6/7, c. 0-40 body circumference apart. Genital markings (Fig. 18c), single median, presetal on viii, ix, xvii-xix, paired, pre- and post-setal, close to the line of the male pores on xviii. Internal characters. Septa 5/6/7 slightly thickened, 7/8-13/14 membranous. Intestine begins in xv.Lateral hearts in x-xii. Holandric, testes sacs paired with narrow ventral connections, large, extending to the dorsalline in x and xi, seminal vesicles large, extending to the dorsal line in xi and xii, those of xienclosed in the testes sacs. Spermathecae (Fig. 14e) paired in vi and vii. DISTRIBUTION. Kepulauan Aru. MATERIAL EXAMINED. 3C Wokam, Aru Kepulauan; Hamburg v3035 (syntypes of mertoni). Polypheretima sepikensis (Ude, 1924) Pheretima sepikensis Ude, 1924 : 81. Pheretima (Pheretima) sepikensis: Ude, 1932 : 135. Metapheretima sepikensis: Sims & Easton, 1972 : 233. DIAGNOSIS. Polypheretima with simple male pores; paired spermathecal pores about one third ofbody circumference apart in furrows 5/6/7. Holandric. Postclitellar genital markings simple,randomly arranged on xviii, with stalked glands discharging into them. ACAECATE PHERETIMOID EARTHWORMS 41 DESCRIPTION. External characters. Length 40-60 mm, diameter 2-3 mm. 100-120 segments.Clitellum xiv-xvi. First dorsal pore 5/6. Setae, 48-50 on vii, 44-48 on xx, setal ring regular(aa = ab=yz = zz). Male pores on small circular porophores c. 0-33 body circumference apart. Female pore single.Spermathecal pores paired, intersegmental in 5/6/7, c. 0-33 body circumference apart. Genital markings (Fig. 18d) small, paired, postsetal on v and vi, slightly lateral to the sper-mathecal pores, small, numerous, randomly arranged on xviii. Internal characters. Septa 5/6-13/14 slightly thickened. Intestine begins in xv. Lateral hearts inx-xii. Holandric, testes sacs large, paired, extending to the dorsal line in x and xi, seminal vesiclesextending to the dorsal line in xi and xii, those of xi enclosed in the testes sacs. Spermathecae(Fig. 14f) paired in vi and vii. Stalked glands discharge through the genital markings associated with the male pores andspermathecal pores. DISTRIBUTION. New Guinea. MATERIAL EXAMINED. 9C, 4A Sepik area, Papua New Guinea; Berlin 6471 (syntypes of sepikensis). Polypheretima brevis (Rosa, 1898) Perichaeta brevis Rosa, 1898a : 288.Amynthas brevis: Beddard, 1900# : 636.Pheretima brevis: Michaelsen, 1900 : 257.Metapheretima brevis: Sims & Easton, 1972 : 180, 233. DIAGNOSIS. Polypheretima with simple male pores ; paired spermathecal pores about half bodycircumference apart in furrows 5/6/7/8. Holandric. DESCRIPTION. External characters. Length 15-20 mm, diameter 1-5-2-5 mm. 70-80 segments.Clitellum xiv-xvi. First dorsal pore 12/13 or 13/14. Setae, 48-52 on vii, 40-50 on xx, setal ringregular on preclitellar segments (aa = ab=yz = zz), with ventral gaps on postclitellar segments(aa = \-5ab = 1 -5yz = 1 -5zz). Male pores simple, on small circular porophore c. 0-28 body circumference apart. Female poresingle. Spermathecal pores paired, intersegmental in 5/6/7/8, c. 0-53 body circumference apart. Genital markings absent.Internal characters. Septa 5/6-13/14 membranous. Intestine begins in xv. Lateral hearts in x-xii. Holandric, testes sacs paired, those of ;c large, extending to the dorsal line, those of xi small,ventral, seminal vesicles in xi and xii, extending to the dorsal line. Pseudoseminal vesicles in xiii.Spermathecae (Fig. 14g) paired in vi-viii. DISTRIBUTION. Christmas Island, Indian Ocean. REMARKS. P. brevis is known only from Christmas Island in the Indian Ocean. The oceanicnature of this island suggests that the record of brevis is the result of introduction through theagency of man. The affinities of brevis with the Papuan representatives of the bifaria species-group(see numerical studies) may indicate that it is indigenous in the New Guinea area. None of the three syntypes possess genital markings, but when more material becomes availableit is possible that markings will be found similar to those of bifaria. MATERIAL EXAMINED. 3C Christmas Island, Indian Ocean; BMNH 1898.10.28.1-2 (syntypes ofbrevis). Polypheretima bifaria (Michaelsen, 1924) Pheretima bifaria Michaelsen, 1924 : 18.Pheretima (Polypheretima) bifaria: Michaelsen, 19346 : 16.Pheretima (Polypheretima) bifaria typica: Michaelsen, 1938 : 171.Metapheretima bifaria bifaria: Sims & Easton, 1972 : 233.Pheretima (Polypheretima) bifaria wirzi Michaelsen, 1938 : 171. 42 E. G. EASTON Metapheretima bifaria wirzi: Sims & Easton, 1972 : 233. ? Pheretima polytheca aruensis Michaelsen, 1910a : 252. ? Pheretima (Polypheretima) polytheca aruensis: Michaelsen, 19346 : 16. ? Metapheretima polytheca aruensis: Sims & Easton, 1972 : 233. DIAGNOSIS. Polypheretima with simple male pores; numerous spermathecal pores in paired bat-teries in furrows 5/6/7/8 and usually 8/9. Holandric. Postclitellar genital markings, two pairs ofpresetal and two pairs of postsetal markings on each segment. DESCRIPTION. External characters. Length 27^49 mm, diameter 1-5-2-5 mm. 99-110 segments.Clitellum xiv-xvi. First dorsal pore 11/12 or 12/13. Setae, 33-45 on vii, 32-40 on xx, setal ringregular with dorsal and ventral gaps (aa= l-5-2ab = 2yz=zz). Male pores simple on large porophores 0-30-0-33 body circumference apart. Female poresingle. Spermathecal pores numerous in paired intersegmental batteries of 1-3 pores in 5/6/7/8and usually 8/9, c. 0-30 body circumference apart. Genital markings (Fig. 19a), simple, single median or closely paired pre- or postsetal on v-ix,paired, presetal in line with the male pores, on xvii and xix, two pairs of presetal and two pairs ofpostsetal, on xviii median to the male pores. Internal characters. Septa 5/6-7/8 thickened, 8/9 membranous, 9/10-12/13 thickened. Intestinebegins in xv. Lateral hearts in x-xiii. Holandric, testes sacs paired, extending to the dorsal line in x and xi, seminal vesicles extendingto the dorsal line in xi and xii, those of xi are enclosed in testes sacs. Spermathecae (Fig. 14h)numerous in paired batteries of 1-3 Spermathecae in vi, vii, viii and usually ix. DISTRIBUTION. New Guinea and possibly Kepulauan Aru. REMARKS. Michaelsen (1938) recognized two subspecies of bifaria, one with single and the otherwith paired preclitellar genital markings. It is considered that these differences indicate individualvariation and that they do not provide the means of recognizing subspecies. The type series of polytheca aruensis could not be located during the preparation of this paper,but from the original description it appears to be closely allied to bifaria and differs considerablyfrom the nominate subspecies of polytheca (known only from Malaya). MATERIAL EXAMINED. 3C Doormanpad-biwak, West Irian; Hamburg v9400 (synty.pes of bifariabifaria). 2C Panarana-del, West Irian; Amsterdam Vol. 247 (bifaria typica: Michaelsen, 1938).1C Panarana-del, West Irian; Amsterdam Vol. 246 (holotype of bifaria wirzi). OTHER RECORDS. ?-, Kobroor, Aru Kepulauan (type(s) of polytheca aruensis). Polypheretima monticola (Beddard, 1912) Pheretima monticola Beddard, 1912: 195.Metapheretima monticola: Sims & Easton, 1972 : 233. DIAGNOSIS. Polypheretima with simple male pores; paired spermathecal pores in furrows 5/6/7/8/9.Holandric. Postclitellar genital markings simple, paired, presetal. DESCRIPTION. External characters. Length c. 130mm, diameter c. 7mm. Segment number notrecorded. Clitellum xiv-xvi. Position of first dorsal pore not recorded. Setal numbers not recorded. Male pores 'conspicuous', widely separated. Condition of female pore(s) not recorded. Sperma-thecal pores paired in 5/6/7/8/9, separation not recorded. Genital markings (Fig. 19b) large, circular or oval, presetal, paired markings on ix, xvii,xix-xx, slightly median to the line of the male pores. Internal characters. All anterior septa present, 9/10-12/13 thickened. Intestine begins in xv.Segments with lateral hearts not recorded. Holandric, testes in x and xi, either free or in large delicate sacs, seminal vesicles in xi and xii.Spermatheca paired in vi-ix, duct short, ampulla spherical, diverticulum long and convoluted,terminating in a small spherical ampulla. ACAECATE PHERETIMOID EARTHWORMS 43 Description after Beddard, 1912; Fig. 19b is an interpretation of the genital field based on thewritten description. DISTRIBUTION. Luzon, Philippines. REMARKS. Beddard's original description lacked detailed information and since the type seriescannot be located, this species is tentatively assigned to the genus Polypheretima where it is placedprovisionally in the bifaria species-group. (The clitellum extends over only three segments and thespermathecal diverticula are apparently simple.) At present monticola is unique in being the only indigenous species of Polypheretima from thePhilippines. RECORDS. 2 specimens, Mt Pulong, Luzon, Philippines (syntypes of monticola). Polypheretima iizukai (Goto & Hatai, 1899) Perichaeta iizukai Goto & Hatai, 1899 : 14. Amynthas iizukai: Beddard, 19000 : 625. Pheretima iizukai: Michaelsen, 1900 : 274; Ohfuchi, 1937 : 39; Kobayashi, 1941a : 260, 266; Kobayashi, 19416:380, 381.Metapheretima iizukai: Sims & Easton, 1972 : 233. DIAGNOSIS. Polypheretima with simple male pores; paired spermathecal pores in furrows 5/6/7/8/9.Holandric. Postclitellar genital markings paired, postsetal. DESCRIPTION. External characters. Length c. 235 mm, diameter 12-15 mm. C. 137 segments.Clitellum xiv-xvi. First dorsal pore 12/13. Setae, c. 34 on iv, c. 40 on v, c. 42 on vi, c. 50 on viii,c. 60 on posterior segments. Setal ring regular. Male pores simple, c. 8 setae apart. Female pore(s) not recorded. Spermathecal pores paired,intersegmental in 5/6/7/8/9, separation not recorded. Genital markings (Fig. 19c) paired, postsetal, in line with the male pores on xix-xxiii.Internal characters. Septa 4/5-7/8 thickened, 8/9/10 absent, 10/11-12/13 thickened. Intestinebegins in xv. Last lateral hearts in xiii. Holandric, testes sacs in x and xi, seminal vesicles in xi and xii, no other details recorded.Spermathecae (Fig. 14i) paired in vi-ix. Description after Goto & Hatai (1899). DISTRIBUTION. Japan. REMARKS. P. iizukai is the only representative of Polypheretima recorded from Japan where itoccurs at the northernmost limit of the genus. Two other Japanese species, Amynthas fuscatus(Goto & Hatai, 1898) and Metaphire grossa (Goto & Hatai, 1898), have postsetal genital markingsand spermathecal pores in furrows 5/6/7/8/9 and may be confused with iizukai. However, theyare readily distinguishable by the presence of intestinal caeca. Although the earthworm fauna of Japan has received considerable attention prior to 1940,this species has been recorded only four times. Of these recorded, one (Ohfuchi, 1937) is suspectsince Ohfuchi noted (p. 41) 'intestinal caeca present' although earlier (p. 39) he had accuratelyrepeated the original description. Kobayashi (194 la & b) recorded this species from only twomountainous districts of central Honshu. The absence of other acaecate species from Japan andfrom the adjacent Asian mainland may indicate that iizukai, by now being confined to moun-tainous refuges, is a relict from a time when Polypheretima was more widespread in Asia. RECORDS. 1C Musashi, Japan (holotype of iizukai, at one time contained in the collections of theUniversity of Tokyo but it could not be located during the preparation of this paper: Dr M.Imajima, private communication). Near Tokyo, Japan (? iizukai: Ohfuchi, 1937). Chubu & Kantodistricts, Japan (iizukai: Kobayashi, 194 la & b, it is uncertain whether these are new records sinceboth papers are in Japanese). 44 E. G. E ASTON Polypheretima gatesi sp. nov.? Pheretima panarana: Gates, 1948 : 159 (non Michae'.sen, 1938 : 167). DIAGNOSIS. Polypheretima with simple male pores; paired spermathecal pores about half bodycircumference apart in furrow 6/7. Holandric. Postclitellar genital markings numerous in irregularpresetal and postsetal rows. DESCRIPTION. External characters. Length 49-54 mm - the two syntypes of this species are bothaclitellate, mature specimens may be considerably larger - diameter c. 2mm. 63-71 segments.Clitellum not recognizable. First dorsal pore 12/13. Setae, 20-24 on vii, 36-4Q on xx, setal ringregular with dorsal and ventral gaps (aa = 2ab = 2yz = zz). Male pores simple on circular porophores c. 0-35 body circumference apart. Female pore(s)not detected. Spermathecal pores paired, intersegmental in 6/7, c. 0-51 body circumference apart. Genital markings (Fig. 20a) numerous, irregularly arranged, pre and postsetal on xviii, presetalon xix.Internal characters. Septa 5/6-13/14 membranous. Intestine begins in xv. Lateral hearts in x-xiii. Holandric, testes sacs paired, those of x extending to the dorsal line, those of xi small, ventral,seminal vesicles large, extending to the dorsal line in xi and xii. Pseudoseminal vesicles in xiii.Spermathecae (Fig. 14j) paired in vii. DISTRIBUTION. New Guinea. a b c Fig. 20 Anterior ventral surface, diagnostic characters, (a) Polypheretima gatesi sp. nov., arrowsindicate furrows with dorsal spermathecal pores; (b) P. panarana; (c) P. taprobanae. ACAECATE PHERETIMOID EARTHWORMS 45 REMARKS. The specimen identified as panarana by Gates (1948) has been tentatively assigned tothis taxon principally because of the greater separation described between the spermathecalpores than is found in panarana sensu stricto. MATERIAL EXAMINED. 2A Local government piggery, Wabag, Mt Hagen, District, Western High-lands, Papua New Guinea, 5 28' S, 143 40' E, coll J W Copland; BMNH 1976.3.184-185(syntypes of gatesi). OTHER RECORDS. ? 1C Mt Wilhelmina, West Irian (panarana: Gates, 1948). Polypher etima panarana (Michaelsen, 1938) Pheretima (Pheretimd) panarana Michaelsen, 1938 : 167.[non Pheretima panarana: Gates, 1948 : 159 (?=P. gatesi)]Metapheretima panarana: Sims & Easton, 1972 : 233. DIAGNOSIS. Polypher etima with simple male pores; paired spermathecal pores about one thirdbody circumference apart in furrow 6/7. Holandric. Postclitellar genital markings in pairedclusters associated with the male pores. DESCRIPTION. External characters. Length c. 31 mm, diameter c. 2-5 mm. c. 69 segments. Clitellumxiv-xvi. First dorsal pore 13/14. Setae, c. 43 on vii, c. 50 on xx, setal ring regular (aa = ab=yz = zz). Male pores simple on conical porophores c. 0-30 body circumference apart. Female pore single.Spermathecal pores paired, intersegmental in 6/7, c. 0-30 body circumference apart. Genital markings (Fig. 20b), medium sized simple papillae arranged in paired clusters of 2-3papillae, postsetal on vii and presetal on viii, median to the spermathecal pores, clusters of up to5 papillae incorporating the male pores on xviii. Internal characters. Septa 5/6-7/8 membranous, 8/9 absent, 9/10-13/14 membranous. Intestinebegins in xv. Lateral hearts in x-xii. Holandric, testes sacs large, paired, those of x extending to the lateral line and those of xiextending to the dorsolateral line, seminal vesicles in xi and xii, those of xi enclosed in the testessacs, those of xii extending to the dorsolateral line. Spermathecae (Fig. 14k) paired in vii. Large glandular masses in vi and vii adjacent to the genital markings, similar masses in xviiiaround the ectal end of the prostatic duct. DISTRIBUTION. New Guinea. MATERIAL EXAMINED. 1C Panarana-del, West Irian; Amsterdam Vol. 292 (holotype of panarana). Polypheretima taprobanae (Beddard, 1892) Perichaeta taprobanae Beddard, 1892 : 163; Beddard, 1895 : 411; Michaelsen, 1897 : 140. Amynthas taprobanae: (= pauli) Beddard, 1900a : 648. Pheretima taprobanae typica: Michaelsen, 1900 : 308. Pheretima taprobanae: Michaelsen, 1903o : 12; Michaelsen, 1907 : 46; Stephenson, 1923 : 312; Michael-sen, 1927 : 371; Aiyer, 1929 : 15, 72; Gates, 1937a : 371; Gates, \937b : 209; Gates, 1945 : 87; Gates,1972a : 220. Metapheretima taprobaena: Sims & Easton, 1972 : 181, 233. Perichaeta pauli Michaelsen, 1897 : 243. Pheretima taprobanae pauli: Michaelsen, 1900 : 309; Moreira, 1903 : 132. Metapheretima pauli: Sims & Easton, 1972 : 233. DIAGNOSIS. Polypheretima with simple male pores; paired spermathecal pores in furrow 7/8.Holandric. DESCRIPTION. External characters. Length 80-145 mm, diameter 4-7 mm. 95-136 segments.Clitellum xiv-xvi. First dorsal pore 12/13. Setae, 70-80 on vii, 60-80 on xx, setal ring regular withventral gaps on preclitellar segments (aa= \-5ab = \-5yz-\-5zz) and with dorsal and ventral gapson postclitellar segments (aa = 2ab = 2yz = 0-7zz). Male pores simple on small porophores c. 0-29 body circumference apart. Female pore single.Spermathecal pores paired, intersegmental in 7/8, c. 0-50 body circumference apart. 46 E. G. EASTON Genital markings (Fig. 20c), small, simple, paired, presetal on vi-ix, slightly median to thespermathecal pores, presetal on xviii-xxii, slightly median to the line of the male pores.Internal characters. Septa 5/6-7/8 thickened, 8/9 membranous, 9/10 absent, 10/1 1/12 membranous,12/13/14 thickened. Intestine begins in xv. Lateral hearts x-xii. Holandric, testes sacs annular in jc and xi, enclosing the lateral hearts and, in xi the seminalvesicles, seminal vesicles in xi and xii, extending to the lateral line. Spermathecae (Fig. 141) pairedin viii. DISTRIBUTION. Introduced records. Brazil, Madagascar, Seychelles, India, Sri Lanka, Queensland,Fiji, Hawaii. REMARKS. P. taprobanae has been reported several times from outside of the Pheretima domain(Gates, 1970c). Its homeland is unknown but the species may come from southeast Asia since thenumerical studies (see above) reveal that taprobanae has higher affinities with iizukai (from Japan)and sempolensis (from Java) than with representatives from New Guinea where it has been sug-gested that this taxon may have originated (Gates, 1972a). MATERIAL EXAMINED. Previously reported. 1C Sri Lanka; BMNH 1904.10.5.165 (syntype of tapro-banae). 6A Sri Lanka; BMNH 1972.1.6-11 (syntypes of taprobanae). 3C Northeast Madagascar;Hamburg v6935 (taprobanae: Michaelsen, 1907). 2C Sri Lanka; BMNH 1904.10.5.163-164(taprobanae: Sims & Easton, 1972). 1C Brazil; Hamburg v9681 (taprobanae Michaelsen, 1927).New records. 15C, 8A Sri Lanka; BMNH 1904.10.5.1286-1296. 12C, 3A Queensland, Australia;BMNH 1972.11.67-73, 1973.14.272-279. 3C, 1A Suva point, Fiji; BMNH 1968.4.85-88. 1CSeychelles; BMNH 1977.21.4. OTHER MATERIAL REPORTED. 1 specimen Sri Lanka (taprobanae: Michaelsen, 1903). 3 specimensTravencore, India (taprobanae: Aiyer, 1929). 6C Sri Lanka (taprobanae: Gates, 1945). 6 specimensSri Lanka; Hamburg v4662 (syntypes ofpauli) although this series is listed in the catalogue of theHamburg Museum it could not be located during the preparation of this paper. 2C, 4A Brazil(taprobanae pauli: Moreira, 1903). Oahu, Hawaii (taprobanae: Gates, 1972) this material wasidentified by Dr G. E. Gates who included the record in his monograph on Burmese earthworms,although it was not noted as a new record (Gates, private communication). Polypheretima grata (Cognetti, 1914) Pheretima (Parapheretima) grata Cognetti, 1914 : 362; Ude, 1932 : 164.Metapheretima grata: Sims & Easton, 1972 : 180, 233. DIAGNOSIS. Polypheretima with male pores within copulatory pouches; spermathecal pores infurrows 5/6/7. Holandric. Stalked glands discharge into copulatory pouches and through papillaeassociated with spermathecal pores. DESCRIPTION. External characters. Length 110-140 mm, diameter c. 4mm. 83-100 segments.Clitellum xiv-xvi. First dorsal pore 13/14. Setae, c. 53 on vii, c. 68 on xx, setal ring regular(aa = ab=yz = zz). Male pores on squat conical penes within copulatory pouches c. 0-30 body circumference apart.Female pore single. Spermathecal pores paired, intersegmental in 5/6/7, c. 0-50 body circumferenceapart. Genital markings (Fig. 17c), small, simple papillae in paired clusters of up to 6, median to thespermathecal pores, postsetal on vi. Internal characters. Septa 5/6-9/10 membranous, 10/11-13/14 thickened. Intestine begins in xv.Lateral hearts in x-xiii. Holandric, testes sacs paired, extending to the dorsal line in jc and xi, seminal vesicles in xiand xii, extending to the lateral line, those ofxi enclosed in the testes sacs. Pseudoseminal vesicleslarge, xiii. Copulatory pouches large, well developed occupying the coelom. Male pores on squatconical penes. Up to 12 stalked glands discharge through small papillae with the copulatorypouches. Spermathecae (Fig. 14m) paired in vi and vii. Stalked glands discharge through the genital markings on vi and into the copulatory pouches. ACAECATE PHERETIMOID EARTHWORMS 47 DISTRIBUTION. New Guinea. REMARKS. The results of the numerical investigations (see above) could be interpreted as indicatingthat this species is closely allied to the bifaria species-group. If this is so then the copulatorypouches would have evolved independently of their development of other species of Polypheretima(polytheca, patae and badia species-groups). MATERIAL EXAMINED. Previously reported. 2C Sepik river, Papua New Guinea (Cognetti alsoprovided the following co-ordinates 4 4' 18" S, 140 7' 15" E. These lie a considerable distancefrom the Sepik river but it has not been possible to establish which data are correct); Leiden 1819(syntypes of grata). 8C Sepik river, Papua New Guinea; Berlin 6466, 6467 (grata: Ude, 1932).New record. 1C Mt Wilhelmina, West Irian; Bogor Ann 065. Polypheretima voeltzkowi (Michaelsen, 1907) Pheretima voeltzkowi Michaelsen, 1907 : 45.Metapheretima voeltzkowi: Sims & Easton, 1972 : 233. DIAGNOSIS. Polypheretima with simple male pores; paired spermathecal pores on the postsetalregion of v. Holandric. DESCRIPTION. External characters. Length 40-68 mm, diameter 2-5-3-5 mm. 85-88 segments.Clitellum xiv-xvi. First dorsal pores 12/13. Setae, 55-60 on vii, 50-70 on xx, setal ring regular(aa = ab=yz = zz). Male pores simple on large circular porophores c. 0-30 body circumference apart. Female porespaired. Spermathecal pores paired, segmental on the postsetal region of v, close to the interseg-mental furrow, c. 0-66 body circumference apart. Genital markings (Fig. 17b) simple, paired, postsetal on xvii, pre- and postsetal on xviii,median to the male pores. Internal characters. Septa 5/6/7 thickened, 7/8-13/14 membranous. Intestine begins in xv. Lateralhearts in x-xii. Holandric, testes sacs paired, extending to the dorsal line in x and xi, seminal vesicles slim,extending to the dorsal line in xi and xii. Spermathecae (Fig. 14n) paired in v, occasionally absent. DISTRIBUTION. Comoro Islands. REMARKS. P. voeltzkowi is known only from the type series. Michaelsen (1907) recorded that thespermathecal pores are intersegmental in furrow 5/6 but re-examination of the type series revealedthat they are on the postsetal portion of segment v close to the intersegmental furrow. The Comoro Islands are outside of the presently accepted range of Polypheretima and indeedof the Pheretima domain. Numerical studies (see above) revealed that this species has highaffinities with the Papuan representatives of the P. bifaria species-group and it is possible that theoccurrence of voeltzkowi in the Comoro Islands is the result of accidental introduction by man. MATERIAL EXAMINED. 3C Great Comoro, Comoro Islands; Hamburg v6936 (syntypes of voeltz-kowi). 5C Data as above; Berlin 4946 (syntypes of voeltzkowi). Polypheretima polytheca species-group DIAGNOSIS. Holandric species of Polypheretima with male pores within copulatory pouches whichlack stalked glands discharging into them. DISTRIBUTION. Indochina, Malaya, Borneo, Western Indonesia. SPECIES INCLUDED, annamensis, aringeana, elongata species-complex (elongata, everetti, kina-baluensis, phacellotheca, stelleri), koyana, lesonea, pentacystis, polytheca, renschi. REMARKS. With the exception of P. grata all the holandric species of Polypheretima with specializedmale pores are included in this species-group. P. grata may be distinguished by the possession of Buru, Balabac Is.,Borneo, ? Madura,East Java, Bali,Lombok, Sumbawa,Komodo, Gt BastardIs. 1 Species with paired spermathecae are coded as 1. 2 aringeana may also be recognized by the form of its genital markings (see Figs 4e and 21 b). stalked glands discharging into the copulatory pouches and the small, numerous genital markingsassociated with the spermathecal pores. Marker characters of the species included in the polytheca species-group are given in Table 7. Polypheretima pentacystis (Rosa, 1891) Perichaeta pentacystis Rosa, 1891 : 400; Beddard, 1895 : 422.Amynthas pentacystis: Michaelsen, 1899 : 95; Beddard, 1900a : 614.Pheretima pentacystis: Michaelsen, 1900 : 293.Metapheretima pentacystis: Sims & Easton, 1972 : 233. DIAGNOSIS. Polypheretima with male pores in copulatory pouches; paired spermathecal poresabout three fifths of the body circumference apart in furrows 4/5/6/7/8/9. Holandric. DESCRIPTION. External characters. Length 110-124 mm, diameter 5-6 mm. 82-113 segments.Clitellum xiv-xvi. First dorsal pore 13/14. Setae, 65-75 on vii, 80-86 on XX, setal ring regularwith ventral gaps (aa = lab 2yz = 2zz). Male pores on squat conical penes within copulatory pouches c. 0-27 body circumference apart.Female pores paired. Spermathecal pores small, paired, intersegmental in 4/5/6/7/8/9, more widelyseparated anteriorly than posteriorly, c. 0-82 body circumference apart at 4/5, c. 0-62 body cir-cumference apart at 8/9. Genital markings (Fig. 21 a) large, simple, paired, presetal on viii, xvii and xix slightly medianto the line of the male pores. Internal characters. Septa 5/6-7/8 thickened, 8/9 membranous, 9/10-12/13 thickened. Intestinebegins in xiv. Lateral hearts in x-xiii. Holandric, testes sacs paired in x and xi but linked dorsally by a narrow connection, seminalvesicles large, reaching the dorsal line in xi and xii. Copulatory pouches extending into the coelom.Spermathecae (Fig. 15a) paired in v-ix. DISTRIBUTION. Seychelles, Madagascar. ACAECATE PHERETIMOID EARTHWORMS 49 REMARKS. The only records of pentacystis, the Seychelles and Madagascar, are from outside of theclassical domain of the Pheretima group of genera. Presumably the species has been introducedinto these islands by the agency of man. It is interesting to note that the variations in sizes anddistributions of the spermathecal batteries among the other species of the polytheca species-groupare clinal and if these trends were to be projected southwestwards from the range of the group, aform with five thecal segments and paired spermathecae would be expected to occur in the Sey-chelles-Madagascar area. At present, there are no explanations available to provide a mechanismfor the dispersal of the polytheca species-group into this region. Due to the extreme dorsal situation of the spermathecal pores in pentacystis, during copulationtorsion of the anterior portion of the body may be necessary by both partners so as to apply theventral region possessing the male pores to the region of the spermathecal pores. Possibly thisbehavioural requirement may act as a barrier preventing successful copulation between pentacystisand its siblings in the polytheca species-group. MATERIAL EXAMINED. 1C Mahe Island, Seychelles; Wein 3996 (holotype of pentacystis). 1C Nossi-be, Madagascar; Hamburg v5113 (pentacystis: Michaelsen, 1899). Polypheretima polytheca (Beddard, 1900) Amynthas polythecus Beddard, 19006 : 897. Pheretima polytheca: Stephenson, 1932 : 229; ( = minuta) Gates, 1935 : 89. Pheretima (Polypheretima) polytheca: Michaelsen, 19346: 16. Metapheretima polytheca: Sims & Easton, 1972 : 181, 233. [non Pheretima polytheca aruensis Michaelsen, 1910a : 252. Pheretima (Polypheretima) polytheca aruensis: Michaelsen, 19346 : 16, 29. Metapheretima polytheca aruensis: Sims & Easton, 1972 : 233 (= ? Polypheretima bifaria).] Amynthas minutus Beddard, 19006: 906. [non Pheretima minuta Gates, 1929: 18 ( = Amynthas exiguus).]Pheretima minuta: Stephenson, 1932 : 222.Pheretima (Polypheretima) minuta: Michaelsen, 19346 : 16.Metapheretima minuta: Sims & Easton, 1972 : 233. DIAGNOSIS. Polypheretima with male pores in shallow copulatory pouches about one quarter ofthe body circumference apart; numerous spermathecal pores in paired batteries about one thirdof the body circumference apart in furrows 5/6/7/8/9. Holandric. DESCRIPTION. External characters. Length 44-50 mm, diameter 1-5-2 mm. 84-105 segments.Clitellum xiv-xvi. First dorsal pore 12/13. Setae, 45-50 on vii, 40-50 on xx, setal ring regular withdorsal and ventral gaps (aa = 2ab = 2yz = zz). Male pores on large circular porophores within shallow copulatory pouches c. 0-24 bodycircumference apart. Female pore single. Spermathecal pores small, numerous in paired batteriesof 6-10 pores intersegmental in 5/6/7/8/9 c. 0-28 body circumference apart. Genital markings (Fig. 21 b), simple paired, presetal on vi and viii slightly median to the sper-mathecal batteries, on xvii, xix-xxi slightly median to the line of the male pores.Internal characters. Septa 5/6-7/8 thickened, 8/9/10 absent, 10/11-12/13 thickened. Intestinebegins in xv. Lateral hearts in x-xii. Holandric, testes sacs large, paired in x and xi, extending to the dorsal line and in xi enclosingthe lateral hearts and seminal vesicles, seminal vesicles large, extending to the dorsal line in xiand xii. Pseudoseminal vesicles well developed in xiii. Copulatory pouches shallow, confined tothe body wall. Spermathecae (Fig. 15b) numerous, arranged in paired, batteries of 6-10 sper-mathecae in vi-ix. DISTRIBUTION. Kelantan, Malaya. REMARKS. The taxon polytheca aruensis, described by Michaelsen (1910) from material collectedin the Aru Islands, is tentatively placed in the synonymy of Polypheretima bifaria mainly onthe arrangement of genital markings. MATERIAL EXAMINED. 1C Kelantan, Malaya; BMNH 1924.3.1.249 (holotype of polytheca). 1CKelantan, Malaya; BMNH 1924.3.1.219 (holotype of minuta). 50 E. G. EASTON .>.. . m abed Fig. 21 Anterior ventral surface, diagnostic characters. (For ontogenetic variation of the malepores, see Fig. 3.) (a) Polypheretima pentacystis, arrows indicate furrows with dorsal spermathecalpores; (b) P. polytheca; (c) P. koyana; (d) P. lesonea sp. nov. Polypheretima koyana (Michaelsen, 1934) Pheretima (Polypheretima) koyana Michaelsen, 19346 : 29.Metapheretima koyana: Sims & Easton, 1972 : 180, 233. DIAGNOSIS. Polypheretima with male pores within large copulatory pouches about one fifth of thebody circumference apart ; numerous spermathecal pores in paired batteries about one fifth of thebody circumference apart in furrows 5/6/7/8/9. Holandric. DESCRIPTION. External characters. Length 125-230 mm, diameter 3-5-5 mm. 162-175 segments.Clitellum xiv-xvi. First dorsal pore 12/13. Setae, 40-45 on vii and xx, setal ring regular on pre-clitellar segments (aa = ab=yz=zz), and with dorsal and ventral gaps on postclitellar segments(aa = I'Sab = l-5yz = zz). Male pores on squat conical penes within crescentic copulatory pouches c. 0-17 body circum-ference apart. Female pore single or paired. Spermathecal pores small, numerous, in pairedbatteries of up to 9 pores, intersegmental in 5/6/7/8/9, c. 0-20 body circumference apart. Genital markings (Fig. 21c) simple, paired, presetal on vii-ix, and postsetal on viii, slightlymedian to the spermathecal batteries, presetal on xvii, xix-xx, slightly median to the male pores.Internal characters. Septa 5/6-7/8 thickened, 8/9/10 absent, 10/11-13/14 thickened. Intestinebegins in xv. Lateral hearts in x-xiii. Holandric, testes sacs small, paired, ventral in x and xi, seminal vesicles large, reaching thedorsal line in xi and xii. Pseudoseminal vesicles in xiii. Copulatory pouches large, extending into ACAECATE PHERETIMOID EARTHWORMS 51 a b Fig. 22 Anterior ventral surface, diagnostic characters. (For ontogenetic variation of themale pores see Fig. 3.) (a) Polypheretima elongata; (b) P. aringeana. the coelom. Spermathecae (Fig. 1 5c), numerous, arranged in paired batteries of up to 9 sper-mathecae in vi-ix. DISTRIBUTION. Mt Dulit, Sarawak. MATERIAL EXAMINED. 2C, 6A Mt Dulit, Sarawak; BMNH 1933.10.6.21-25 (syntypes of koyand).3C, 2A Data as above; Hamburg vl!954, vl!952 (syntypes of koyand). Polypheretima lesonea sp. nov. DIAGNOSIS. Polypheretima with male pores within copulatory pouches about one third of thebody circumference apart ; paired spermathecal pores in furrows 6/7/8 and often 5/6, numerous,spermathecal pores in paired batteries in 8/9. Holandric. DESCRIPTION. External characters. Length 73-88 mm, diameter 2-3 mm. 112-131 segments.Clitellum xiv-xvi. First dorsal pore 11/12. Setae, 34-40 on vii, 30-36 on xx, setal ring regularwith ventral gaps on preclitellar segments (aa = lab = 2yz = 2zz), and with dorsal and ventralgaps on postclitellar segments (aa 2ab = 2yz = zz). Male pores on squat conical penes within copulatory pouches, c. 0-33 body circumferenceapart. Female pore single. Spermathecal pores small, intersegmental, in 6/7/8/9 and occasionally5/6 also, pores paired in 5/6/7/8, c. 0-42 body circumference apart and in paired batteries of 8-10pores in 8/9 where the ventrahnost pores are c. 0-42 body circumference apart and the dorsalmostare close to the dorsal line, additional spermathecal pores in 7/8 occasionally. 52 E. G. EASTON Genital markings (Fig. 2 Id) paired, presetal on xix-xxii and occasionally xvii in line with themale pores. Internal characters. Septa 5/6-7/8 thickened, 8/9 absent, 9/10 membranous, 10/1 1-12/13 thickened.Intestine begins in xvi. Lateral hearts in x-xiii. Holandric, testes sacs large, paired, reaching the dorsal line in x and xi, enclosing the lateralhearts and, in xi, the seminal vesicles, seminal vesicles small in xi, large, reaching the dorsal linein xii. Coelomic pouches small, invading the coelom. Spermathecae (Fig. 15d) in vii-ix andoccasionally vi, paired in vi-viii, in paired batteries of 8-10 spermathecae in ix, additional sper-mathecae in viii occasionally. DISTRIBUTION. Sumatra. REMARKS. All of the syntypes of this species have three thecal segments (vii-ix) and are bithecal inthe first two and polythecal in the last segment. The single individual from Maurarupit has anadditional pair of spermathecae in vi and is polythecal in viii (2 spermathecae in each battery). MATERIAL EXAMINED. 8C Flat plain mostly covered with sedge grass and scrub trees and with fewcultivations or villages, soil damp, loamy, shallow, Sungaikolong, Central Sumatra, 107'S,101 48' E, altitude c. 50 m, coll G Lincoln 28 May 1973 British University Dragon Expedition;BMNH 1975.7.3-12 (syntypes of lesonea). 1C Flat ground beside river, moist black soil and mud,c 5 miles south of Maurarupit, beside road to Lapat, central Sumatra, 2 45' S, 102 54' E,altitude c. 160m, coll G Lincoln 5 Jun 1973 British University Dragon Expedition; BMNH1975.7.2. Polypheretima elongata species-complexMetapheretima elongata species-complex Sims & Easton, 1972 : 252; Easton, 1976 : 38. DIAGNOSIS. Polypheretima with male pores in shallow copulatory pouches lacking stalked glands ;numerous spermathecal pores in paired batteries in furrows 5/6 and/or 6/7. Holandric, post-clitellar genital markings one pair per segment, simple presetal near to the line of the male pores. DESCRIPTION. External characters. Length 40-360 mm, diameter 1-5-10 mm. 100-220 segments.Clitellum xiv-xvi. First dorsal pore 12/13. Setae 20-130 on vii, 36-86 on xx, occasionally setaea and b enlarged, setal ring regular with ventral gaps (aa= l-5ab = \-5yz = l-5zz). Male pores on squat penes within shallow copulatory pouches c. 0-25 body circumferenceapart. Female pore single. Spermathecal pores small, numerous arranged in paired ventrolateralbatteries, of up to 28 pores, intersegmental in 5/6 and/or 6/7, occasionally absent. Genital markings (Fig. 22a) simple, large, paired presetal on xix and successive segments inline with or slightly median to the male pores, occasionally on vi, vii and xvii.Internal characters. Septa 4/5-7/8 thickened, 8/9 membranous, 9/10 absent, 10/1 1-13/14 thickened.Intestine begins in xv. Lateral hearts in x-xii and usually xiii. Holandric, testes sacs large, paired, extending to the dorsal line in x and xi, seminal vesiclespaired in xi and xii, the anterior pair enclosed in the testes sacs. Pseudoseminal vesicles in xiiiand xiv. Copulatory pouches shallow, confined to the body wall. Spermathecae (Fig. 1 5e) numer-ous in paired batteries of up to 28 spermathecae in vi and/or vii, occasionally absent. DISTRIBUTION. Indigenous records. Kepulaud Taulaud; Sangihe; Celebes; Buru; Balabac Island,Palawan; Borneo; ? Madura; east Java; Bali; Lombok; Sambawa; Komoda; Gt Bastard Island,Flores. Four of the five species included in this species-complex are known only from the indigenousrange. The fifth, elongata, has been introduced into may parts of the world. REMARKS. The species elongata, everetti, kinabaluensis, phacellotheca and stelleri form a singlespecies-complex. They may be distinguished from one another by comparisons of the number ofsetae on vii and the size of the spermathecal batteries (Fig. 23). The spermathecal index may becalculated by substituting the mean size of the anterior and posterior spermathecal batteries of anindividual for a and b in the formula x=\/(a 2 + b 2 ). The four species, everetti, phacellotheca, ACAECATE PHERETIMOID EARTHWORMS 53 16O-1 MO- 100-80- elongata 70- everetti & phacellotheca kinabaluensis & stelleri Spermathecal index Fig. 23 Polypheretima elongata species-complex : correlation between the number of setae on segmentvii and the spermathecal index, \/(a z + b z ). (a and b are the mean number of spermathecae in abattery in furrows 5/6 and 6/7 respectively.) stelleri and kinabaluensis, need additional characters to be assessed for differentiation. In the firstpair everetti has spermathecal pores in furrows 5/6 and 6/7 while phacellotheca has spermathecaein furrow 5/6 only ; in the second stelleri has numerous setae on vii (up to 1 30) while kinabaluensishas few setae (less than 40). Full details of the variation in the setal and spermathecal systems ofthe members of the elongata species-complex are given by Easton (1976). Polypheretima elongata (Perrier, 1872) Perichaeta elongata Perrier, 1872 : 124.Metapheretima elongata'. Easton, 1976 : 40.Perichaeta biserialis Perrier, 1875 : 1044.Perichaeta acystis Beddard, 1895: 423.(For full synonomy see Easton, 1976.) DIAGNOSIS. P. elongata species-complex with numerous setae (usually about 80 on vii in clitellatespecimens but up to 1 30 in large individuals) ; small spermathecal batteries (rarely more than 3spermathecae in each battery) in furrows 5/6/7 or 5/6 or 6/7 only or absent. Spermathecal batteriesusually present in about 50 % of the clitellate portion of indigenous populations to only 1 5 % ofthe clitellate portion of introduced populations (Easton, 1976). DISTRIBUTION. Indigenous records. ? Madura; east Java; Bali; Lombok; Sumbawa; Komodo;? Gt Bastard Island, Flores; ? southeast Celebes. Introduced records. South and central America (type locality, Peru), Madagascar, Comoros,Sri Lanka, India, Pakistan, Bangladesh, Burma, Andaman Islands, Thailand, Malaya, Sumatra,west and central Java, Kepulaud Taulaud, Philippines, Taiwan, Kei Islands, Australia, PapuaNew Guinea, New Britain (new record), New Caledonia, Caroline Islands, Ryukyu Islands,Hawaii, Tahiti, West Indies, Africa. (See Gates, 19720 : 182 for further details.) 54 E. G. EASTON REMARKS. Individuals of this species often lack spermathecae. Athecate individuals are especiallynumerous in introduced populations in which, presumably, specimens without spermathecaereproduced parthenogenetically (Gates, \912a : 182). The incidence of thecate individuals can beused to establish the indigenous range of the species by analysing the composition of long series(Easton, 1976). Polypheretima everetti (Beddard & Fedarb, 1895) Perichaeta everetti Beddard & Fedarb, 1895 : 69. Perichaeta papillata Beddard & Fedarb, 1895 : 71. Perichaeta sarawacensis Beddard & Fedarb, 1895: 71. Perichaeta bar ami Michaelsen, 1896 : 203. Amynthas stelleri seriatus Michaelsen, 1899 : 44. Amynthas stelleri klabatensis Michaelsen, 1 899 : 46. Amynthas stelleri bonensis Michaelsen, 1899 : 45 [non Pheretima (Pheretima) stelleri bonensis: Michaelsen, 1934a : 108 (=P. phacellothecd)].Pheretima stelleri koroensis Michaelsen, 19106 : 109.Pheretima stelleri mahakkami Michaelsen, 1922 : 25.Pheretima (Pheretimd) beranensis Michaelsen, 1928a : 23.Pheretima (Polypheretima) beranensis tinjarana Michaelsen, 19346 : 25.Pheretima (Pheretima) baritoensis Michaelsen, 1932 : 9.Metapheretima everetti: Easton, 1976 : 41. (For full synonomy see Easton, 1976.) DIAGNOSIS. P. elongata species complex with numerous setae (up to 130 on vii in large individuals);intermediate sized spermathecal batteries (usually 6-12 spermathecae in each battery of largeindividuals) in furrows 5/6/7. Spermathecal batteries present in aclitellate as well as clitellateindividuals (Easton, 1976). DISTRIBUTION. Balabac Island, Palawan (type locality); north and west Celebes; Borneo (up to2400 m); Lombok (c. 350-450 m only).This species is unknown outside its indigenous range. REMARKS. On Lombok this species has been recorded only from localities at altitudes between350 and 450 m. Samples from lower altitudes contained the species elongata which is rare at higheraltitudes. No samples of earthworms are known from above 450 m on Lombok. Although alti-tudes would appear to be the primary factor governing the distribution of everetti (and elongata),it should be noted that, on Lombok, the samples of everetti were from natural woodland (those ofelongata being from cultivated land). All the records of everetti (also stelleri and phacellothecd)from Celebes are from the northern and western region, an area of forest. On Mt Kinabalu,Borneo, the species everetti occurs at altitudes up to 2400 m, being sympatric from 2100 m withthe high altitude species kinabaluensis. Although on both Lombok and Mt Kinabalu everetti issympatric with other members of the elongata species-complex, there is no indication of hybridi-zation among them. Beddard & Fedarb (1895) reported that the type locality of Perichaeta everetti is Mt Kinabalu,Sabah but Easton (1976) redesignated Balabac Island, Palawan as the type locality under Recom-mendation 72E of the International Code of Zoological Nomenclature. Polypheretima kinabaluensis (Beddard & Fedarb, 1895) Perichaeta kinabaluensis Beddard & Fedarb, 1895 : 71.Metapheretima kinabaluensis: Easton, 1976 : 41.(For full synonomy see Easton, 1976.) DIAGNOSIS. P. elongata species-complex with few setae (less than 40 on vii); intermediate sizedspermathecal batteries (usually 6-12 spermathecae in each battery of large individuals) in furrows5/6/7. Spermathecal batteries present in aclitellate as well as clitellate individuals (Easton, 1976). DISTRIBUTION. Mt Kinabalu, Sabah. 2100-2750 m (type locality Tamburgare, 2350 m).This species has not been recorded outside its indigenous range. ACAECATE PHERETIMOID EARTHWORMS 55 REMARKS. This species is known only from high altitudes on Mt Kinabalu where there is a special-ized montane fauna and flora. Although samples collected on Mt Kinabalu at 2100 and 2400 mcontained both everetti and kinabaluensis, there is no indication of hybridization. Polypheretima phacellotheca (Michaelsen, 1899) Amynthas phakellotheca (sic) Michaelsen, 1899 : 47.Metapheretima phacellotheca: Easton, 1976 : 44.(For full synonomy see Easton, 1976.) DIAGNOSIS. P. elongata species-complex with numerous setae (up to 80 on vii in large individuals);large spermathecal batteries (9-12 spermathecae in each battery of large individuals) in furrow5/6 only. Spermathecal batteries present in aclitellate as well as clitellate individuals (Easton, 1976). DISTRIBUTION. Northeast Celebes (type locality; Mt Masarang, near Tomohon), Buru. REMARKS. This species is the only member of the elongata species-complex known from Buruwhich is the most easterly indigenous record of the complex. Morphologically it closely resemblesstelleri from which it may be distinguished by the restriction of spermathecal batteries to furrow 5/6. Polypheretima stelleri (Michaelsen, 1891) Perichaeta stelleri Michaelsen, 1891 : 39.Amynthas stelleri annectens Michaelsen, 1899 : 42.Metapheretima stelleri: Easton, 1976 : 44.(For full synonomy see Easton, 1976.) DIAGNOSIS. P. elongata species-complex with numerous setae (up to 130 on vii in large individuals) ;very large spermathecal batteries (up to 28 spermathecae in each battery of large individuals) infurrows 5/6/7. Spermathecal batteries present in aclitellate as well as clitellate individuals (Easton,1976). DISTRIBUTION. Sangihe (type locality), Kepulaud Taulaud, Celebes (Bone valley and Matinangrange).This species has not been encountered outside its indigenous range. REMARKS. In Celebes stelleri has been recorded from Bone valley (c. 400 m) and the Matinangrange (c. 1500 m) together with everetti. Polypheretima aringeana (Beddard, 1900) Amynthas aringeanus Beddard, 19006 : 899. Pheretima argineana: Stephenson, 1932 : 203. Pheretima (Polypheretima) aringeana: Michaelsen, 19346 : 16. Metapheretima aringeana: Sims & Easton, 1972 : 180, 233. DIAGNOSIS. Polypheretima with male pores in shallow copulatory pouches lacking stalked glands;numerous spermathecal pores arranged in paired batteries, in furrows 5/6/7. Holandric, post-clitellar genital markings, 1 pair per segment, central portion of each marking differentiated intoseveral small pigmented areas (Fig. 4e, 22b). DESCRIPTION. External characters. Length 60-200 mm, diameter 3-5 mm. 100-150 segments.Clitellum xiv-xvi. First dorsal pore 12/13. Setae, 60-70 on vii, and xx, setal ring slightly crowdedventrally with ventral gaps on preclitellar segments (aa = I- Sab = 2yz = 2zz), evenly spaced on post-clitellar segments (aa = ab=yz = zz). Male pores on large conical penes within copulatory pouches c. 0-27 body circumferenceapart. Female pore single. Spermathecal pores numerous, arranged in paired, lateral batteries of7-10 pores, intersegmental in 5/6/7, c. 0-50 body circumference apart. 56 E. G. EASTON Genital markings (Fig. 22b) simple paired presetal on v-vii and postsetal on v and vi, slightlymedian to the spermathecal batteries ; large paired markings differentiated central areas, occupy-ing the whole length of the segment, in line with the male pores on xvii and xix.Internal characters. Septa 4/5-7/8 thickened, 8/9/10 absent, 10/11-12/13 thickened. Intestinebegins in xv. Lateral hearts in x-xiii. Holandric, testes sacs annular in x and xi, enclosing the lateral hearts and, in xi, the seminalvesicles, seminal vesicles small in xi, large in xii. Pseudoseminal vesicles large in xiii. Copulatorypouches shallow, confined to the body wall. Spermathecae (Fig. 15f), numerous, arranged inpaired batteries of 7-10 spermathecae in vi and vii. DISTRIBUTION. Malaya. MATERIAL EXAMINED. Previously reported. 3C, 4A Kelantan, Malaya; BMNH 1904.10.5.1000-1001, 1924.3.1.232-234 (syntypes of aringeana), other specimens from this series are deposited atCambridge, England, they were not examined.New record. 11C, 6A, Kelantan, Malaya; BMNH 1972.12.9-11, 1977.9.1-9. Polypheretima annamensis (Stephenson, 1931) Pheretima annamensis Stephenson, 1931 : 60.Metapheretima annamensis: Sims & Easton, 1972 : 233. DIAGNOSIS. Polypheretima with male pores in copulatory pouches; paired spermathecal poresabout one fifth of the body circumference apart in furrow 6/7 only. Holandric. DESCRIPTION. External characters. Length 84-87 mm - both of the specimens on which thisdescription is based are immature, adult individuals may be expected to be considerably larger -diameter c. 6mm. c. 177 segments. Clitellum xiv-xvi. First dorsal pore 11/12. Setae, 82-86 onvii, c. 94 on xx, setal ring regular on preclitellar segments (aa ab=yz = zz), with ventral gaps onpostclitellar (aa=l-5ab= l-5yz= l-5zz). Male pores on squat penes within large copulatory pouches c. 0-23 body circumference apart.Female pores not detected. Spermathecal pores paired, intersegmental in 6/7, c. 0-20 body cir-cumference apart. Genital markings absent. Internal characters. Septa 5/6-7/8 thickened, 8/9/10 absent, 10/11-13-14 thickened. Intestinebegins in xv. Lateral hearts in x-xiii. Holandric, testes sacs of x annular, those of xi small, paired lateral, seminal vesicles large in xiand xii, reaching the dorsal line. Copulatory pouches shallow, confined to the body wall. Sper-mathecae (Fig. 15g) paired in vii. DISTRIBUTION. South Vietnam. MATERIAL EXAMINED. 1C, 1A Lang Bian Peaks, South Vietnam; BMNH 1930.2.7.10-11 (syntypesof annamensis). Polypheretima renschi (Ude, 1932) Pheretima (Pheretima) renschi Ude, 1932 : 141.Metapheretima renschi: Sims & Easton, 1972 : 233. DIAGNOSIS. Polypheretima with male pores in copulatory pouches ; paired spermathecal pores infurrows 7/8/9. Holandric. DESCRIPTION. External characters. Length 220-250 mm, diameter 8-1 2 mm. C. 160 segments.Clitellum xiv-xvi. Position of first dorsal pore not recorded. Setae, c. 72 on vii, c. 80 on xiii,small, widely spaced. Male pores within copulatory pouches separated by 18 setae (estimated to be c. 0-25 bodycircumference apart). Female pores not recorded. Spermathecal pores paired, intersegmental in7/8/9, separated by 18 setae (estimated to be c. 0-25 body circumference apart). Genital markings absent. ACAECATE PHERETIMOID EARTHWORMS 57 Internal characters. Septa 7/8 membranous, 8/9 and probably 9/10 absent, 10/1 1-14/15 thickened.Intestine begins in xv. Disposition of lateral hearts not recorded. Holandric, testes sacs paired, median in x and xi, seminal vesicles in xi and xii. Copulatorypouches confined to body wall, penes conical. Spermathecal, paired in viii and ix, ampulla sacshaped with a distinct, long, narrow duct. Diverticula three times as long as main duct with a beanshaped ampulla. Description after Ude (1932). DISTRIBUTION. Flores. RECORDS. 2 specimens, west Flores (syntypes of renschi). Polypheretima badia species-group DIAGNOSIS. Polypheretima with a pair of simple presetal genital markings on each of severalpostclitellar segments. Metandric. DISTRIBUTION. Lombok, Flores. SPECIES INCLUDED, badia, elberti, kellneri, ? sibogae, swelaensis. REMARKS. The metandric species of Polypheretima form two species-groups. Those from Papuaare placed in the patae species-group, while those from the Lesser Sunda Islands comprise thebadia species-group. The numerical investigation carried out during this revision indicate thatthese two groups are closely related in spite of their separate distributions. The oligochaete faunaof the area between these two species-groups is poorly known and it is uncertain whether the twogroups are the end members of a continuous group of metandric species. One species, sibogae, can be only tentatively assigned to the badia-group since data regarding itsanterior male organs are deficient but the high affinities of this species with the other members ofthe species-group (see numerical studies) indicate that it is probably metandric. The relationships among the taxa assigned to this group have not been studied in detail. Twoof the species, badia and swelaensis, are certainly closely allied and possibly conspecific since theregions of their male pores are modified in the form of slight ridges which extend from xvii to xix. Marker characters of the species assigned to the badia species-group are given in Table 8. Table 8 Marker characters of the members of the Polypheretima badia species-group Polypheretima kellneri (Ude, 1932) Pheretima (Metapheretimd) kellneri Ude, 1932 : 177.Metapheretima kellneri: Sims & Easton, 1972 : 233. DIAGNOSIS. Polypheretima with paired Spermathecal pores about one half of the body circum-ference apart in furrows 4/5/6/7/8/9. Metandric. DESCRIPTION. External characters. Length c. 180mm, diameter c. 4mm. Segment number notrecorded. Clitellum xiv-xvi. Setae, c. 42 on viii, c. 60 on ix, c. 62 on xvi, c. 65 on xxi, setal ringregular (aa = ab=yz=zz). 58 E. G. E ASTON Male pores simple, c. 0-40 body circumference apart. Female pore single. Spermathecal porespaired, intersegmental in 4/5/6/7/8/9, c. 0-50 body circumference apart. Genital markings absent. Internal characters. Anterior septa present and those anterior to 13/14 slightly thickened. Intestinebegins in xv. Disposition of lateral hearts not recorded. Metandric, testes sacs paired in xi, seminal vesicles large in xii. Spermathecae, paired in v-ix,ampulla sac shaped with a short, poorly differentiated duct, diverticular slightly longer than mainportion and with a cylindrical end chamber. Description after Ude (1932). DISTRIBUTION. Lombok. REMARKS. P. kellneri is known only from the type series whose members lacked genital markings.It is probable that when more (mature) material becomes available individuals will be found withgenital markings resembling the markings of other members of the badia species-group. RECORDS. Lombok (type(s) of kellneri). Ude (1932) recorded this material as being in the BerlinMuseum but no record of it could be found during the preparation of this paper; Dr G. Hart-wich, personal communication. Polypheretima sibogae (Michaelsen, 1922) Pheretima sibogae Michaelsen, 1922 : 23. Pheretima (Polypheretima) sibogae: Michaelsen, 19346 : 16. Ephemitra sibogae: Sims & Easton, 1972 : 180, 232. -r . #! abed Fig. 24 Anterior ventral surface, diagnostic characters. (For ontogenetic variation of themale pores see Fig. 3.) (a) Polypheretima sibogae', (b) P. badia; (c) P. swelaensis; (d) P. elberti. ACAECATE PHERETIMOID EARTHWORMS 59 DIAGNOSIS. Polypheretima with numerous spermathecal pores arranged in paired batteries abouttwo fifths of the body circumference apart in furrows 4/5/6/7/8/9. Meroandric. One pair of presetalgenital markings on each of several postclitellar segments. DESCRIPTION. External characters. Length c. 50 mm, diameter c. 3 mm. C. 73 segments. Clitellumxiv-xvi. First dorsal pore 12/13. Setae, c. 47 on vii, c. 58 on xx, setal ring regular with ventralgaps (aa = lab = 2yz = 2zz). Male pores simple, c. 0-30 body circumference apart. Female pores paired. Spermathecal poresnumerous, arranged in paired batteries of 5-1 1 pores, intersegmental in 4/5/6/7/8/9, c. 0-40 bodycircumference apart. Genital markings (Fig. 24a), simple paired, presetal, slightly median to the spermathecal poresin ix, postsetal, close to the median line on vii, presetal, in line with the male pores on xvii.Internal characters. Anterior septa posterior to 5/6 present, unthickened. Beginning of the intes-tine not recognized. Disposition of the lateral hearts unknown. Meroandric (proandric or metandric), testes sacs paired, no other details of the anterior malereproductive system known. Spermathecae (Fig. 15h) numerous in paired batteries of 5-11spermathecae in v-ix. DISTRIBUTION. Lombok. REMARKS. P. sibogae is known only from the holotype which is poorly preserved. Due to itscondition the position of the testes, whether it was proandric or metandric, cannot be established.The species is tentatively included in the badia species-group since its genital markings and distri-bution resemble those of other members of the group. This species was included within the genus Ephemitra ( = Metapheretima SS) by Sims & Easton(1972) but their decision was based on the assessment of the few characters observable from theholotype. In the present numerical studies sibogae has high affinities with the metandric species ofPolypheretima from Lombok and Flores. MATERIAL EXAMINED. 1C Lombok; Leiden 1823 (holotype of sibogae). Polypheretima badia (Ude, 1932) Pheretima (Metapheretima) badia (? part) Ude, 1932 : 171.Metapheretima badia: Sims & Easton, 1972 : 233. DIAGNOSIS. Polypheretima with paired spermathecal pores about one third of the body circum-ference apart in furrows 5/6/7/8/9 and often 4/5. Metandric. One pair of presetal genital markingson each of sevetal postclitellar segments. DESCRIPTION. External characters. Length 85-160 mm, diameter 3-7mm. 68-105 segments.Clitellum xiv-\xvi. First dorsal pore 11/12 or 12/13. Setae 33-42 on vii, 50-70 on xx, setal ringregular (aa = ab=yz = zz). Male pores simple, superficial or slightly invaginated, c. 0-33 body circumference apart. Femalepores paired. Spermathecal pores paired, intersegmental in 4/5/6/7/8/9, anterior pair (? and nextpair) often absent, c. 0-33 body circumference apart. Genital markings (Fig. 24b) simple, paired, presetal on vi-ix slightly median to the spermathe-cal pores, postsetal on viii close to the median line, presetal on xvii-xxiii median to the male pores.Body wall of xvii-xix bearing male pores and genital markings elevated to form paired ridges.Internal characters. Anterior septa posterior to 5/6 present and membranous or slightly thickened.Intestine begins in xv. Lateral hearts in x-xii. Metandric, testes sacs paired in xi with narrow dorsal processes, seminal vesicles in xii, reachingthe dorsal line. Pseudoseminal vesicles in xiv. Spermathecae very similar to those of swelaensis(Fig. 15j) paired in v-ix, anterior pair (? and the next pair) often absent. DISTRIBUTION. West Flores and (possibly) east Lombok. REMARKS. P. badia was described originally from two series, one collected on Lombok and theother on Flores. The species is now known only from the four extant specimens of the series from 60 E. G. EASTON Floras since Easton (1976) found that the single extant specimen from Lombok was the polythecal,holandric species Polypheretima everetti (Beddard & Fedarb, 1895). None of these individualshave been dissected so it must be assumed that Ude had other material at his disposal when hedescribed the internal anatomy. The above description now differs somewhat from the original. In the original account of badiathe spermathecal pores were reported as being in furrows 5/6/7/8/9 or 6/7/8/9. Of the specimensre-examined from Flores two have spermathecae opening into furrows 5/6/7/8/9 while the othertwo have spermathecae opening into furrows 4/5/6/7/8/9. It appears that the original descriptionis unreliable, and it is therefore uncertain whether the species occurs on Lombok. MATERIAL EXAMINED. 4C West Flores; Berlin 7213 (syntypes of badia). Polypheretima elberti (Ude, 1932) Pheretima (Metapheretimd) elberti Ude, 1932 : 175.Metapheretima elberti: Sims & Easton, 1972 : 233. DIAGNOSIS. Polypheretima with paired spermathecal pores about half the body circumferenceapart in furrows 5/6/7/8/9. Metandric. One pair of presetal genital markings on each of severalpostclitellar segments. DESCRIPTION. External characters. Length 50-70 mm, diameter 3-4 mm. C. 80 segments. Clitellumxiv-xvi. First dorsal pore 12/13. Setae, c. 44 on vii, c. 72 on xx, setal ring slightly crowded dorsallyon preclitellar segments (2aa = 2ab=yz = zz), regular on postclitellar segments (aa = ab=yz=zz). Male pores on short, conical penes within shallow copulatory pouches c. 0-35 body circum-ference apart. Female pore single. Spermathecal pores paired, intersegmental in 5/6/7/8/9, c. 0-45body circumference apart. Genital markings (Fig. 24d), small, paired, presetal, in line with the spermathecal pores onvi-ix, slightly median to the male pores on xvii, xix-xxi. Internal characters. Anterior septa posterior to 5/6 present and membranous. Intestine begins inxv. Lateral hearts in x-xii. Metandric, testes sacs paired, ventral in xi, seminal vesicles large, extending to the dorsal linein xii. Pseudoseminal vesicles absent. Copulatory pouches confined to body wall. Spermathecae(Fig. 15i) paired in vi-ix. DISTRIBUTION. Lombok. REMARKS. The type series could not be located during the preparation of this paper. New materialreported here represent the second record for this species. MATERIAL EXAMINED. New record. 2C Lombok; BMNH 1975.7.314.OTHER RECORDS. Lombok (syntypes of elberti). Polypheretima swelaensis (Ude, 1932) Pheretima (Metapheretima) swelaensis Ude, 1932 : 178. Amynthas swelaensis: Sims & Easton, 1972 : 237. ? Pheretima (Metapheretima) badia (part) Ude, 1932 : 171. DIAGNOSIS. Polypheretima with paired spermathecal pores about one third of the body circum-ference apart in furrows 5/6/7/8. Metandric. One pair of presetal genital markings on each ofseveral postclitellar segments. DESCRIPTION. External characters. Length c. 147 mm, diameter c. 5 mm. c. 132 segments. Clitellumxiv-\xvi. First dorsal pore 12/13. Setae, c. 80 on vii, c. 100 on xx, setal ring regular (aa = ab=yz =zz). Male pores on squat penes within shallow copulatory pouches c. 0-23 body circumference apart.Female pores paired. Spermathecal pores paired, intersegmental in 5/6/7/8, c. 0-37 body cir-cumference apart. ACAECATE PHERETIMOID EARTHWORMS 61 Genital markings (Fig. 24c) paired, presetal, slightly median to the spermathecal pores onvii-ix\ postsetal, median to the spermathecal pores on vii-viii; presetal, slightly median to themale pores on xvii-xx. Body wall of xvii-xix bearing male pores and genital markings elevatedto form paired ridges. Internal characters. Septa 5/6-13/14 present and slightly thickened. Intestine begins in xv. Lateralhearts in x-xii. Metandric, testes sacs small, paired ventral in xi, seminal vesicles extending to the dorsal linein xii. Copulatory pouches shallow, confined to the body wall. Spermathecae (Fig. 15j) paired invi-viii. DISTRIBUTION. Lombok. REMARKS. P. swelaensis closely resembles badia in the form of the male pores and the spermathecaebut it may be distinguished by the separation and arrangement of the spermathecal pores and thehigher setal numbers of swelaensis. MATERIAL EXAMINED. New record. 1C, 1A Lombok; BMNH 1975.7.13-14. OTHER RECORDS. Lombok (type(s) of swelaensis). The two extant members of the type series,Berlin 7215, are here reidentified as Amynthas sp. (Both are athecate and precise identification isimpractical.) Lombok; (? badia: Ude, 1932). Polypheretima patae species-group DIAGNOSIS. Polypheretima with numerous genital markings arranged in transverse rows.Metandric. DISTRIBUTION. New Guinea. SPECIES INCLUDED, coplandi, huonensis, kershawae, patae. REMARKS. The patae species-group contains the metandric Polypheretima^ from New Guinea. Itsmembers may be recognized by the distributions and separations of the spermathecal pores and,in mature individuals ( ?), the distribution of genital markings. P. coplandi, for example, is knownonly from four aclitellate specimens which lack genital markings. Marker characters of the speciesincluded in the patae species-group are given in Table 9. It is noteworthy that in species with lessthan the full complement of spermathecae, reduction has occurred principally in the posteriorthecal segments and not, as is common in other species-groups, in the anterior segments. The affinities of the patae group are with the badia species-group which includes the metandricforms from the Lesser Sunda Islands (see numerical studies). Polypheretima patae sp. nov. DIAGNOSIS. Polypheretima with paired spermathecal pores about half body circumference apart infurrows 4/5/6/7/8/9. Metandric. Genital markings numerous, presetal in transverse rows. DESCRIPTION. External characters. Length c. 75 mm, diameter c. 3 mm. 86-94 segments. Clitellumxiv-xvi. First dorsal pore 12/13. Setae 44-48 on vii, 46-51 on xx, setal ring regular on preclitellarsegments (aa = ab=yz = zz), with dorsal gaps on postclitellar segments (aa = ab=yz = \zz). Male pores on squat penes within copulatory pouches c. 0-24 body circumference apart. Femalepores paired spermathecal pores paired, intersegmental in 4/5/6/7/8/9, c. 0-55 body circumferenceapart. Genital markings (Fig. 25a), transverse rows of c. 10 small oval papillae, presetal on ix, xvii-xxii, lateral limits of rows median to the male pores.Internal characters. Septa 5/6-13/14 membranous. Intestine begins in xv. Lateral hearts in x-xii. Metandric, testes sacs paired, extending to the dorsal line in xi, seminal vesicles extending to thedorsal line in xii. Pseudoseminal vesicles in xiv. Copulatory pouches small, only just invading thecoelom, penes conical and short. Spermathecae (Fig. 15k) paired in v-ix. DISTRIBUTION. North east New Guinea. 62 E. G. EASTON Table 9 Marker characters of the members of the Polypheretima patae species-group MATERIAL EXAMINED. 1C, 2A In moist soil of dark sandy loam with a high organic matter contentand covered with grass and ferns, c. 200 m from sea, just north of Bunu village, 50 km northalong coast road from Madang, Papua New Guinea, 4 52' S, 145 49' E, coll J W Copland14 Nov 1971; BMNH 1976.3.186-188 (syntypes of patae). 3C, 3A Upper Kaironk valley, Simbairegion, Madang district, Papua New Guinea 1900-2100 m, coll R N H Bulmer 14 Nov 1973;BMNH 1976.2.22-27. Polypheretima kershawae sp. nov. DIAGNOSIS. Polypheretima with paired spermathecal pores about one quarter of the body cir-cumference apart in furrows 4/5/6/7/8. Metandric. Genital markings numerous, pre- and postsetal in transverse rows. DESCRIPTION. External characters. Length 35-45 mm, diameter c. 3 mm. C. 85 segments. Clitellumxiv-xvi. First dorsal pore 12/13. Setae c. 45 on vii, c. 41 on xx, setal ring regular (aa = ab=yz = zz). Male pores on short conical penes within copulatory pouches c. 0-24 body circumference apart.Female pores paired. Spermathecal pores paired, intersegmental in 4/5/6/7/8, 0-26 body circum-ference apart. Genital markings (Fig. 25b) small, numerous, arranged in pre- and postsetal rows on xvii-xx,lateral limits of rows slightly median to male pores. Internal characters. Septa 5/6-12/13 slightly thickened. Intestine begins in xv. Lateral hearts inx-xii. Metandric, testes sacs paired, large, extending to the dorsal line in xi, seminal vesicles in xii.Copulatory pouches confined to the body wall. Spermathecae (Fig. 15m) paired in v-viii. DISTRIBUTION. North east New Guinea. MATERIAL EXAMINED. 4C, 1A Top 15cm of alluvial clay soil (derived from Gabbro), organiccontent 15-30% C/N ratio 8 or 9, gentle ridge with mixed montane forest with Podocarpus,Eleocarpacae, Lauacae, Cumoniaceae (dominant), Bismark range, East Highland district, PapuaNew Guinea, 2500 m, 5 57' S, 145 15' E, rainfall 900 cm/year, coll D R Kershaw 20 Jul 1971 ;BMNH 1975.5.167-171 (syntypes of kershawae). 2C Data as above, coll 14 Jul 1971; BMNH1976.5.172-173. 1C Wau, North east New Guinea, 1200 m, coll J Sedlacer 13 Feb 1965; Honolulu. Polypheretima coplandi sp. nov. DIAGNOSTIC. Polypheretima with paired spermathecal pores about two fifths of the body cir-cumference apart in furrows 4/5/6/7. Metandric. DESCRIPTION. External characters. Length 70-92 mm; the four specimens are aclitellate, maturespecimens may be considerably larger. Diameter c. 3 mm. C. 1 16 segments. Clitellum not recogniz-able. Dorsal pores not recognizable anterior to 19/20. Setae 36-38 on vii, 28-32 on xx, setal ringregular with ventral and dorsal gaps on preclitellar segments (aa=l-5ab=l-5yz=zz), dorsal andventral gaps slightly larger on postclitellar segments (aa = 2ab = 2yz=zz). ACAECATE PHERETIMOID EARTHWORMS 63 00033GOOQOO a b c Fig. 25 Anterior ventral surface, diagnostic characters. (For ontogenetic variation of the malepores see Fig. 3.) (a) Polypheretima patae sp. nov.; (b) P. kershawae sp. nov. ; (c) P. huonensissp. nov. Male pores on squat conical penes within copulatory pouches c. 0-19 body circumference apart.Female pores paired. Spermathecal pores paired, intersegmental in 4/5/6/7, c. 0-42 body circum-ference apart. Genital markings not detected.Internal characters. Septa 5/6-13/14 membranous. Intestine begins in xv. Lateral hearts in x-xii. Metandric, testes sacs paired but linked by a superoesophageal connection, in xi, seminalvesicles in xii, extending to the dorsal line. Pseudoseminal vesicles in xiii. Copulatory pouchesconfined to the body wall. Spermathecae (Fig. 151) paired in v-vii. DISTRIBUTION. North east New Guinea. REMARKS. The four specimens on which this species is described lack genital markings. It is prob-able that mature individuals will possess markings of the type present in other members of thepatae, species-group. MATERIAL EXAMINED. 2A Bank of creek, D. A. S. F. Piggery, 3 miles from Goroka township,Eastern Highlands, Papua New Guinea, 6 02' S, 145 22' E, coll J W Copland; BMNH1976.3.182-183 (syntypes of coplandi). 2A Data as above; BMNH 1977.1.213-214. Polypheretima huonensis sp. nov. DIAGNOSIS. Polypheretima with paired Spermathecal pores about one third of the body circum-ference apart in furrows 5/6/7. Metandric. Genital markings numerous, presetal in transverserows. 64 E. G. E ASTON DESCRIPTION. External characters. Length c. 50 mm, diameter c. 3 mm. C. 96 segments. Clitellumxiv-xvi. First dorsal pore 12/13. Setae, c. 39 on vii and xx, setal ring with dorsal and ventralgaps on preclitellar segments (aa = lab = 2yz = zz). Male pores on squat penes within copulatory pouches c. 0-20 body circumference apart.Female pores paired. Spermathecal pores paired, intersegmental in 5/6/7, c. 0-33 body circum-ference apart. Genital markings (Fig. 25c), transverse rows of c. 4 small oval papillae, presetal on vii-ix,paired pre- and postsetal papillae on xvii and xix in line with the male pores.Internal characters. Septa 5/6-13/14 membranous. Intestine begins in xv. Lateral hearts in x-xii. Metandric, testes sacs paired, extending to the dorsal line in xi, seminal vesicles extending tothe dorsolateral line in xii. Pseudoseminal vesicles in xiv. Copulatory pouch small, restricted to thebody wall, penes conical and short. Spermathecae (Fig. 15n) paired in vi and vii. DISTRIBUTION. North east New Guinea. MATERIAL EXAMINED. 1C Garden soil. Timbe valley, Huon Peninsula, Papua New Guinea, 1500 m,6 00' S, 147 02' E, coll I L Owen, Aug 1976; BMNH 1977.21.1 (holotype of huonensis). PLANAPHERETIMA Michaelsen, 1934 Megascolex (part): Vaillant, 1889 : 80. Perichaeta (part): Beddard, 1895 : 388. Amynthas (part): Beddard, 1900a : 612. Pheretima (part): Michaelsen, 1900 : 234. Pheretima (Archipheretima) (part) Michaelsen, 1928a : 7. Pheretima (Planapheretima) Michaelsen, 19346 : 15. Planapheretima: Sims & Easton, 1972 : 209, 233. TYPE SPECIES. Pheretima moultoni Michaelsen, 1913, original designation. DIAGNOSIS. Megascolecidae with an oesophageal gizzard in viii. Intestinal caeca sometimes pre-sent, intestinal walls often with glandular areas, intestinal gizzards absent. Body mainly flatteneddorsoventrally, setae usually crowded ventrally, creeping sole often present. Male pores simple,never within copulatory pouches. Spermathecal diverticular simple, usually ectal in origin. DESCRIPTION. Body cylindrical or flattened dorsoventrally, often with a glandular ventral surface(creeping sole) on the anterior region of the body. Clitellum annular, extending over three or moresegments (xiii, xiv-xvi, xvii). First dorsal pore between 6/7 and 12/13. Setae perichaetine, evenlydistributed round each segment or crowded, often densely, on the ventral surface. Lateral heartsin x-xii and sometimes xiii. Oesophagus with a well-developed gizzard in viii; calciferous glands and dorsal pouches absent.Intestine begins in xiv, xv or xvi, often modified by the development of glandular walls or a pairof lateral caeca, intestinal gizzards absent. In the absence of externally recognizable adaptationsto arboreal life, the presence of glandular intestinal walls may be used to recognize Chinesemembers of this genus. Holandric. The testes of each segment are enclosed in single or paired stout sacs which usuallyoccupy most of the coelom and often enclose the anterior seminal vesicles and the lateral hearts ofjc and xi. Seminal vesicles paired in xi and xii. Prostates racemose. Paired combined male andprostatic pores on the ventral surface of xviii in the setal ring. Male pores usually simple or oncircular porophores, rarely on slim superficial penes (Fig. 29a), on penes carried on circular poro-phores (Fig. 3g) or on a raised area (Fig. 29b). Copulatory pouches absent. Ovaries free in xiii.Oviducts lead to single or closely paired, midventral, equatorial pore(s) on xiv. Spermathecaeeach differentiated into duct and ampulla; diverticula simple, usually ectal in origin and usuallyas long as or longer than the main duct and ampulla. Spermathecae arranged in pairs in one tofive adjacent segments between v and ix. Spermathecal pores small or small slitlike openings,always intersegmental. Genital markings of the discrete type or annular ridges ; diffuse markings absent. Discrete genitalmarkings may be single or paired, segmental or intersegmental, they are never random or ACAECATE PHERETIMOID EARTHWORMS 65 numerous (cf. Polypheretima bifaria and patae species-group). The glandular tissue associatedwith the genital markings is usually restricted to the body wall and only rarely invades the coelomin the form of a stalked gland. The area around the male pores may be infrequently elevated abovethe body surface. DISTRIBUTION. (Fig. 7.) In areas of high humidity in China, Burma, Sumatra, Borneo, Celebesand New Guinea. NUMERICAL STUDIES. The taxa of the genus Planapheretima listed in Table 1 (72-85) were sub-jected to a numerical analysis utilizing the characters listed in Table 2. The configuration of taxawith the first and third vectors of the principle co-ordinate analysis employed as axes producedthe greatest degree of clustering. The use of the first and second vectors produced similar but morediffuse clusters. Recognition of the clusters is considerably enhanced by the addition of the MSTwith graded linkages (Fig. 26). Two divisions, indicated by circular and square symbols, may be recognized. The taxa of Divi-sion I from the Indo-Australasian archipelago (indicated by circular symbols) all have simpleintestines while those of Division II from Asia (square symbols) have intestines modified by thedevelopment of glandular walls and/or intestinal caeca. 82 84 83' 76" 81 Fig. 26 Principal co-ordinates analysis of 14 species here assigned to Planapheretima (72-85 of Table1): the configuration of species with the vectors corresponding to the first and third latent roots. The linkages of the added MST are graded to indicate percentage similarities; , +90%; , 85-90%, , -85%. Two major assemblages are recognized: Division I - circular and triangular symbols (circles - subulata species-group, triangles - species allied to the subulata species- group).Division II - square symbols (bambophila species-group). 66 E. G. E ASTON Division I contains five taxa (indicated by solid circular symbols), they are situated closetogether on the first and third vectors and possess relatively high mutual MST linkages. Mor-phologically these taxa are similar in having simple male pores on circular porophores and (whenpresent) paired genital markings; all are assigned to the subulata species-group. The other fourtaxa of Division I (indicated by open circular symbols) have, with the exception of 83 and 85,lower MST linkages. Unlike the taxa of the subulata species-group, they exhibit considerablediversity in the form of the male pores and the genital markings. It is proposed to consider eachas a separate species. It has not been possible to examine any representatives of the taxa of Division II before thenumerical studies were undertaken so assessments were derived from the original descriptions(Gates, 1972 : 169 in the case of arboricold). All are now assigned to the continens species-group. A summary of the phenetic classification based on this numerical investigation is given inTable 10. Table 10 Phenetic classification and checklist of the genus Planapheretima DIVISION I subulata species-group celebensis (77)moultoni (78)pallenscens (79)rufomaculata (80)subulata (81) -ambulatrix (82)-hasselti (83)-maculata (84)-nieuwenhuisi (85)-sera DIVISION II -bambophila species-grou{ arboricola (76)bambophila (75)continens (72)lacertina (73)tenebrica (74) Numbers in parentheses indicate taxa assessed in numerical studies (see Figs 6 and 26). REMARKS. It is clear from the general numerical study (see above) that the acaecate and caecatespecies included in this genus form a single phenetic group, distinct from all of the other acaecatespecies assessed. However, in the absence of representatives of the caecate genera from thesecomputations, no information is available about the affinities of the caecate members of Plana-pheretima with the caecate genera of the Pheretima group. Unfortunately the two representativesof Planapheretima which were included in the general appraisal of the Pheretima group by Sims& Easton (1972) were both acaecate. In P. moultoni and celebensis, paired, intersegmental markings are closely associated with themale pores and superficially resemble the crescentic markings found in Metapheretima andPleionogaster. Key to the species of the genus Planapheretima 1 First spermathecal pores in furrow 4/5First spermathecal pores in furrow 5/6First spermathecal pores in furrow 6/7First spermathecal pores in furrow 7/8 2 Three thecal segments ....Five thecal segments .... 3 Intestinal caeca absent (Borneo) Intestinal caeca present (rudimentary) (China) 258 103 subulata (p. 69) 4 continens (part) (p. 75) 5(1) 8(1) 10(1) ACAECATE PHERETIMOID EARTHWORMS Spermathecae as Fig. 27a ...... Spermathecae as Fig. 27b ....... One thecal segment ........ Two thecal segments ....... Three thecal segments ....... Four thecal segments ....... Intestinal caeca absent ....... Intestinal caeca simple, rudimentary ..... Intestinal caeca multiple ....... Spermathecal pores lateral ; intestinal wall simple (Celebes) . 67 moultoni (p. 68) pallescens (p. 68) rufomaculata (p. 71) hasselti (p. 71) continens (part) (p. 75) 6 7 lacertina (p. 77)arboricola (p. 76)celebensis (p. 70) Spermathecal pores ventrolateral ; intestinal wall glandular in segments xx-xc (China) tenibrica (p. 78)One thecal segment ............. 9 Two thecal segments ......... ambulatrix (p. 71) Postclitellar genital field as Fig. 29c maculata (p. 73) Postclitellar genital field as Fig. 30c ........ sera (p. 73) Males pores c. 0-15 body circumference apart; postclitellar genital markings (Fig. 29d) single, median presetal (Borneo) meuwenhuisi (p. 74) Male pores c. 0-25 body circumference apart; postclitellar genital markings not of this form or absent (China) ......... bambophila (p. 78) Planapheretima subulata species-group DIAGNOSIS. Planapheretima with simple intestines lacking glandular walls and caeca. Male poreson simple porophores, genital markings paired. i j k I m Fig. 27 Spermathecae. (a) Planapheretima moultoni; (b) P. pallescens; (c) P. subulata; (d) P.celebensis; (e) P. ambulatrix; (f) P. hasselti; (g) P. maculata; (h) P. nieuwenhuisi; (i) P. continens;(j) P. arboricola; (k) P. lacertina; (1) P. tenebrica; (m) P. bamophilia. All scales 0-5 mm unlessotherwise indicated. (See also Fig. 30f.) 68 E. G. EASTON DISTRIBUTION. Borneo, Celebes, New Guinea. SPECIES INCLUDED, celebensis, moultoni, pallescens, rufomaculata, subulata. REMARKS. Most of the species included within the subulata species-group are readily distinguish-able on the distribution of their spermathecal pores ; subulata 5 pairs 4/5/6/7/8/9, celebensis 4pairs 5/6/7/8/9, moultoni and pallescens 3 pairs 4/5/6/7 and rufomaculata 1 pair 5/6. The affinitiesof moultoni and pallescens are discussed below (see remarks of moultoni). Planapheretima moultoni (Michaelsen, 1913) Pheretima moultoni Michaelsen, 19136 : 90; Michaelsen, 1914 : 59.Pheretina (Archipheretima) moultoni: Michaelsen, 1928a : 14.Pheretima (Planapheretima) moultoni: Michaelsen, 19346 : 15.Planapheretima moultoni: Sims & Easton, 1972 : 209, 233. DIAGNOSIS. Planapheretima with a simple intestine; spermathecal pores in furrows 4/5/6/7.Spermathecae as Fig. 27a. DESCRIPTION. External characters. Length 45-55 mm, diameter 2-2-5 mm 93-100 segments.Body depressed, concave ventrally, with creeping sole. Colouration; light yellowish grey with upto 20 small dark violet-brown or nearly black spots around each dorsal pore, the spots fusing toform a ring with the pore marked by a white spot, the rings fuse to form a median line whichbecomes larger posteriorly, the number of irregular spots diminish posteriorly as well. Clitellum^xiii-xvi. First dorsal pore 9/10. Setae c. 100 on each segment, setal ring crowded ventrally withoutdorsal or ventral gaps (5aa = 5ab=yz = zz). Male pores on slightly raised conical porophores c. 0-30 body cirumference apart. Femalepore single. Spermathecal pores small in 4/5/6/7, c. 0-33 body circumference apart. Genital markings (Fig. 28a) paired, pre- and postsetal, slightly median to the male pores onxviii. Internal characters. Anterior septa delicate, some in the region of the gizzard possibly absent.Intestine simple, begins in xv. Lateral hearts in x-xiii. Holandric, testes sacs paired, large in ;c and xi, seminal vesicles small, extending to the lateralline in xi and xii. Spermathecae (Fig. 27<z) paired in v-vii. DISTRIBUTION. Borneo. REMARKS. P. moultoni and pallescens may be distinguished only by the form of the Spermathecaeand the absence of genital markings in pallescens. Since the holotype of pallescens has been dis-sected nearly to destruction, it is difficult to assess the validity of these distinctions and possiblywhen more material becomes available for study, pallescens may prove to be a junior synonym ofmoultoni. MATERIAL EXAMINED. 2C Mt Poi, Sarawak; Hamburg v8090 (syntypes of moultoni). 3C, 2A MtPoi, Sarawak; Hamburg v!0510 (moultoni: Michaelsen, 1928). Planapheretima pallescens (Michaelsen, 1928) Pheretima (Archipheretima) pallescens Michaelsen, 1928or : 15.Pheretima (Planapheretima) pallescens: Michaelsen, 19346 : 15.Planapheretima pallescens: Sims & Easton, 1972 : 231. DIAGNOSIS. Planapheretima with a simple intestine; spermathecal pores in furrows 4/5/6/7.Spermathecae as Fig. 27b. DESCRIPTION. External characters. Length c. 60 mm (aclitellate), diameter c. 2-2 mm. C. 96 seg-ments. Body depressed ventrally, creeping sole on xvi-xx. Colouration; bright yellow with areddish, mother of pearl lustre and a sparsely developed brown, irregularly defined line on theanterior segments of the body. Clitellum not developed. First dorsal pore at either 10/11 or 11/12.Setae, c. 122 on v, c. 141 on ix, c. 134 on xvii. ACAECATE PHERETIMOID EARTHWORMS 69 M 3 " "\ n 0---\ 0o cO abed Fig. 28 Anterior ventral surface, diagnostic characters, (a) Planapheretima moultoni;(b) P. subulata; (c) P. celebensis; (d) P. rufomaculata. Male pores on small porophores outside the region of the creeping sole, c. 0-33 body circum-ference apart. Female pore(s) not recorded. Spermathecal pores in 4/5/6/1, c. 0-33 body circum-ference apart. Genital markings not detectable. Internal characters. Anterior septa delicate, 8/9/10 not detected and probably absent. Beginningof intestine not recorded. Intestine simple. Disposition of lateral hearts not recorded. Holandric, testes sacs large, paired in x and xi, seminal vesicles small in xi and xii. Spermathe-cae (Fig. 27b), paired in v-vii. Description after Michaelsen (1928); and the author after examination of the remains of theholotype. DISTRIBUTION. Borneo. REMARKS. This species is similar to moultoni with which it may be conspecific (see above). MATERIAL EXAMINED. 4 spermathecae, gizzard, oesophagus, part of anterior intestine and anteriormale reproductive system, Mt Penrissen, Sarawak; Hamburg v 10522 (remains of holotype ofpallescens). Planapheretima subulata (Michaelsen, 1899) Amynthas subulatus Michaelsen, 1899 : 29; Beddard, 19000 : 641.Pheretima subulata: Michaelsen, 1900 : 307.Metapheretima subulata: Sims & Easton, 1972 : 233. 70 E. G. EASTON DIAGNOSIS. Plcmapheretima with a simple intestine ; spermathecal pores in furrows 4/5/6/7/8/9. DESCRIPTION. External characters. Length 60-70 mm, diameter c. 3 mm. 105-106 segments.Body flattened, concave ventrally, creeping sole poorly developed. Colouration; (preservedspecimen), brownish dorsally, light yellowish white ventrally, clitellum yellowish grey. Clitellumxiv-xvi. First dorsal pore 6/7. Setae, c. 80 on vii, c. 60 on xx, setal ring crowded ventrally withdorsal gaps on preclitellar segments (4aa = 4ab=yz = Q-5zz), without dorsal or ventral gaps onpostclitellar segments (4aa = 4ab=yz = zz). Male pores at the centre of large circular porophores c. 0-30 body circumference apart. Femalepores paired. Spermathecal pores large in furrows 4/5/6/7/8/9, c. 0-30 body circumference apart. Genital markings (Fig. 28b) paired, in line with the male pores, presetal on xix and xx, postsetalon x, xi and xvii. Internal characters. Anterior septa present and delicate. Intestine simple, begins in xvi. Lateralhearts in x-xii. Holandric, testes sacs large, paired, extending to the dorsal line, in x and xi, seminal vesicleslarge, extending to the dorsal line in xi and xii. Spermathecae (Fig. 27c), paired in v-ix. DISTRIBUTION. Celebes. REMARKS. Sims & Easton (1972) placed this species in Metapheretima on the basis of its originaldescription but the subsequent examination of the type series revealed the depressed body,crowded ventral setae and creeping sole which characterize the genus Planapheretima. MATERIAL EXAMINED. 1C Central Celebes; Hamburg v5192 (syntypes of subulatd). 2C 1A CentralCelebes; Hamburg v5193 (syntypes of subulata). The original description of this species was based on two series of specimens, both collected byP. & U. Sarasin in February 1895 from central Celebes. The localities were: Hill country in theregion of the Kalaena river, c. 400 m, 5 Feb 1895 and southern foothills of Takalekadjo, c. 1000 m,7 Feb 1895. Although the labels clearly indicate that these specimens were collected in centralCelebes by P. and M. Sarasin, they do not indicate from which locality each series originated. Planapheretima celebensis (Michaelsen, 1899) Amynthas celebensis Michaelsen, 1899 : 32; Beddard, 1900a : 642.Pheretima celebensis : Michaelsen, 1900 : 261.Planapheretima celebensis: Sims & Easton, 1972 : 233. DIAGNOSIS. Planapheretima with simple intestine ; spermathecal pores in furrows 5/6/7/8/9. DESCRIPTION. External characters. Length c. 60 mm, diameter c. 2 mm, C. 90 segments. Shape ofbody and form of ventral surface not recorded. Colouration; (preserved specimen) bright brownishyellow dorsally, grey ventrally, clitellum dark violet grey. Clitellum $xiii-xvi. First dorsal pore6/7. Setae, c. 49 on vi, c. 48 on x, c. 40 on xvii, c. 44 on xxvi, setal ring crowded ventrally (lab =yz). Male pores on oval porophores c. 0-29 body circumference apart. Female pore(s) not recorded.Spermathecal pores in furrows 5/6/7/8/9, c. 0-50 body circumference apart. Genital markings (Fig. 28c) paired, in line with the male pores, presetal on xix-xxi, postsetalon viii, intersegmental at 17/18, 18/19. Internal characters. Anterior septa present and delicate. Beginning of intestine not recorded.Intestine simple. Lateral hearts in x-xiii. Holandric, testes sacs paired, large in x and xi, seminal vesicles in xi and xii. Spermathecae(Fig. 27d) paired in vi-ix. Description based on Michaelsen, 1899, 1900; Fig. 28c is an interpretation of the genital fieldbased on the written description. DISTRIBUTION. Celebes. RECORDS. 1C Takalekadjo range, central Celebes; Hamburg v5188 (holotype of celebensis).Although this specimen is listed in the catalogue of the Hamburg Museum it could not be locatedduring the preparation of this paper: Dr M. Dzwillo, personal communication. ACAECATE PHERETIMOID EARTHWORMS 71 Planapheretima rufomaculata (Gates, 1948) Planapheretima rufomaculata Gates, 1948 : 162.Planapheretima rufomaculata'. Sims & Easton, 1972 : 233. DIAGNOSIS. Planapheretima with a simple intestine; spermathecal pores in furrow 5/6 only. DESCRIPTION. External characters. Length 43-45 mm, diameter c. 4 mm. Segment number notrecorded. Body depressed, creeping sole not recognized. Colouration; pigmentation restricted tothree longitudinal, irregular stripes, a median dorsal dark red stripe and two lateral light redstripes. Clitellum ^xiii-xvi. First dorsal pore 11/12. Setal numbers not recorded, setal ringcrowded ventrally. Male pores on circular, widely spaced, porophores separated by 25-26 setae. Female poresingle. Spermathecal pores in 5/6, c. 0-50 body circumference apart. Genital markings (Fig. 28d) closely paired, intersegmental at 9/10, 16/17 and 19/20, segmental,slightly median to male pores on xviii. Internal characters. Anterior septa present and delicate. Intestine simple, begins in xv. Lateralhearts in ix-xiii. Holandric, testes sacs single, U-shaped, extending to the dorsal line in x, those of xi not seenbut assumed to be similar, seminal vesicles in xi and xii, details not recorded. Spermathecae,paired in vi, duct as long as main ampulla, diverticulum ental, tubular, nearly as long as mainaxis. Stalked glands associated with the genital markings. Description after Gates, 1948; Fig. 28d is an interpretation of the genital field based on thewritten description. DISTRIBUTION. New Guinea. RECORDS. 2C Near Idenburg river, West Irian (holotype and paratype of rufomaculata). The typeseries of this species is absent from the collections of the Museum Zoologicum Bogoriense whereReynolds & Cook (1976) stated it had been deposited: Dr S. Kadarsan, personal communication. Planapheretima ambulatrix (Michaelsen, 1934) Pheretima (Planapheretima) ambulatrix Michaelsen, 19346 : 22.Planapheretima ambulatrix: Sims & Easton, 1972 : 233. DIAGNOSIS. Planapheretima with a simple intestine; spermathecal pores in furrows 6/7/8. DESCRIPTION. External characters. Length c. 55 mm, diameter c. 2-5 mm. C. 100 segments. Bodydepressed with a creeping sole occupying the whole ventral surface. Colouration; (preserved speci-men) yellowish to yellowish grey without pigmentation. Clitellum \xiii-xvii. First dorsal pore notrecognized. Setae, c. 120 on vii, c. 130 on xx, setal ring crowded ventrally without dorsal or ventralgaps (5aa = 5ab=yz = zz). Male pores on minute elongate penes c. 0-25 body circumference apart (Fig. 29a). Female pore(s)not recognized. Spermathecal pores small in 6/7/8, c. 0-25 body circumference apart. Genital markings not recognized. Internal characters. Anterior septa present and delicate. Intestine simple, begins in xvi. Lateralhearts in x-xii. Holandric, testes sacs simple, U-shaped and large in x and xi, seminal vesicles extending to thedorsal line in xi and xii. Spermathecae (Fig. 27e) paired in vii and viii. DISTRIBUTION. Borneo. MATERIAL EXAMINED. 1C 5A Mt Dulit, Sarawak; BMNH 1933.10.6.6 (holotype and paratypes ofambulatrix). 2A Data as above; Hamburg vl!955 (paratypes of ambulatrix). Planapheretima hasselti (Horst, 1883) Megascolex hasselti Horst, 1883 : 190; Vaillant, 1889 : 80.Perichaeta hasselti: Horst, 1885 : 5; Beddard, 1895 : 426. 72 E. G. EASTON a Fig. 29 bed Anterior ventral surface, diagnostic characters, (a) Planapheretima ambulatrix;(b) P. hasselti; (c) P. maculata; (d) P. nieuwenhuisi. Amynthas hasselti: Beddard, 1900a : 638. Pheretima hasselti: Michaelsen, 1900:271 [non Michaelsen, 1922:30 (= Amynthas morrisi species-group)]. Planapheretima hasselti: Sims & Easton, 1972 : 180, 233.Pheretima (Planapheretima) frondicola Michaelsen, 19346 : 17.Planapheretima frondicola: Sims & Easton, 1972 : 233. DIAGNOSIS. Planapheretima with a simple intestine; spermathecal pores in furrows 5/6/7. DESCRIPTION. External characters. Length 50-54 mm, diameter 2-3 mm. 90-95 segments. Bodydepressed with a creeping sole occupying the ventral surface. Colouration ; (preserved specimen),pale yellowish grey or grey with lighter intersegmental furrows. Clitellum xiii-xvi. First dorsalpore 12/13. Setae, c. 1 10 on vii, c. 70 on xx, setal ring crowded ventrally without dorsal or ventralgaps (6aa = 6ab=yz=zz). Male pores simple, c. 0-13 body circumference apart on large, oval porophores extending ontoxvii and xix (Fig. 29b). Female pore single. Spermathecal pores large in 5/6/7, c. 0-22 body cir-cumference apart. Genital markings absent. Internal characters. Anterior septa present and delicate. Intestine simple, begins in xv. Lateralhearts in x-xiii. Holandric, testes sacs paired, large, extending to the dorsal line in x and xi, seminal vesicles ofxi small, extending to the lateral line, those of xii larger, extending to the dorsal line. Spermathecae(Fig. 27f) paired in vi and vii, ACAECATE PHERETIMOID EARTHWORMS 73 DISTRIBUTION. Sumatra and Borneo. REMARKS. The material identified as hasselti by Michaelsen (1922) is here assigned to the Amynthasmorrisi species-group since it lacks a depressed body, has crowded ventral setae and pairedintestinal caeca confirmed by examination of Michaelsen's material: Leiden, 1854. The species frondicola has been included within the synonymy of hasselti since the two typeseries differ from each other only in that the clitellum is longer and the raised areas bearing themale pores are more fully developed in frondicola. This is the only representative of Planapheretima recorded from Sumatra. MATERIAL EXAMINED. 2C Lebang, Sumatra; Leiden 1853 (holotype of hasselti). 1C, 1A Mt Dulit,Sarawak; BMNH 1933.10.6.9 (syntypes of frondicola). 2A Locality as above; Hamburg vl!957(syntypes of frondicola). Planapheretima sera sp. nov. DIAGNOSIS. Planapheretima with a simple intestine ; spermathecal pores in furrow 6/7 only. Malepores on elongate porophores (Fig. 30c). DESCRIPTION. External characters. Length c. 78 mm, diameter c. 3 mm. C. 115 segments. Bodydepressed, creeping sole present on postclitellar segments. Colouration; yellowish brown withdark brown or red spots on dorsal and lateral surfaces, clitellum purple. Clitellum %xiii-xvi.First dorsal pore 8/9 or 9/10. Setae c. 70 on vii and xx, setal ring crowded ventrally without dorsalor ventral gaps (5aa = 5ab=yz=zz). Male pores postsetal on large oval posteriorly directed porophores which occupy the wholelength of the segment, c. 0-20 body circumference apart. Female pore(s) not seen. Spermathecalpores small in 6/7, c. 0-40 body circumference apart. Genital markings (Fig. 30c) paired, presetal, in line with the male pores on xix and xx.Internal characters. Anterior septa present and delicate. Intestine simple, begins in xv. Lateralhearts in x-xiii. Holandric, testes sacs single, U-shaped, extending to the dorsolateral line in x and xi, seminalvesicles in xi and xii, those of xi enclosed in the testes sacs. Spermathecae (Fig. 30f) paired in vii,diverticulum very long, convoluted. DISTRIBUTION. Borneo. MATERIAL EXAMINED. 1C On ivy-like leaf of 20m tall shrub, near old campsite, Royal Geo-graphical Society camp 4, ridge top forest, Gunong Mulu, Sarawak, altitude 1970 m, 4 02'N,114 54' E, coll J Dring 2030 hrs, 22 Aug 1977; BMNH 1977.21.2 (holotype of sera). 1C On leafof herb, 1 m up bank of dried up temporary stream, Royal Geographical Society camp 3, GunongMulu, Sarawak, altitude 1450 m, coin Dring 2100 hrs, 9 Sep 1977; BMNH 1977.212 (paratype ofsera). Planapheretima maculata (Ude, 1925) Pheretima maculata Ude, 1925 : 104. Pheretima (Archipheretimd) maculata: Michaelsen, 19280 : 18; Ude, 1932 : 120. Pheretima (Planapheretima) maculata: Michaelsen, 19346 : 15. Planapheretima maculata: Sims & Hasten, 1972 : 233. Pheretima (Archipheretimd) scandens Michaelsen, 1928a : 18. Pheretima (Planapheretima) scandens: Michaelsen, 19346 : 15. Planaphertima scandens: Sims & Easton, 1972 : 233. DIAGNOSIS. Planapheretima with a simple intestine; spermathecal pores in furrow 6/7 only. Malepores surrounded by annular ridges (Fig. 29c). DESCRIPTION. External characters. Length 30-40 mm, diameter 2-3 mm. 50-77 segments. Bodydepressed with creeping sole on the ventral surface. Colouration; whole body highly iridescent,yellowish brown with, on the dorsal surface, irregularly arranged rust-red or dark brown spots 74 E. G. E ASTON which form a ring-shaped pattern around each dorsal pore, clitellum violet brown. Clitellumxiii-xvi. First dorsal pore 9/10 or 10/11. Setae, 40-59 on vii and xx, setal ring crowded ventrallywithout dorsal or ventral gaps (5aa = 5ab=yz = zz). Male pores simple, c. 0-33 body circumference apart. Female pore single. Spermathecal poressmall in 6/7, c. 0-33 body circumference apart. Genital markings (Fig. 29c) in the form of a ridge surrounding each male pore.Internal characters. Anterior septa delicate, 8/9 absent. Intestine simple, begins in xv. Lateralhearts in xi-xiii and possibly x. Holandric, testes sacs paired, large in x and xi; seminal vesicles in xi and xii, those of xienclosed in the testes sacs of that segment. Spermathecae (Fig. 27g) paired in vii. DISTRIBUTION. Borneo. REMARKS. The type series of scandens differs from the original description of maculata in the formof the spermathecal diverticulum, this difference is considered insufficient to justify the separationof two forms. MATERIAL EXAMINED. 1C Mt Penrissen, Sarawak; Hamburg v!0515 (holotype of scandens).OTHER RECORDS. Mt Murud, Brunei; (type(s) of maculata). Planapheretima nieuwenhuisi (Michaelsen, 1922) Pheretima nieuwenhuisi Michaelsen, 1922 : 47.Pheretima (Archipheretima) nieuwenhuisi: Michaelsen, 1928a : 22.Pheretima (Planapheretima) nieuwenhuisi: Michaelsen, 19346 : 15.Planapheretima nieuwenhuisi: Sims & Easton, 1972 : 181, 233. DIAGNOSIS. Planapheretima with a simple intestine; spermathecal pores in furrows 7/8/9. DESCRIPTION. External characters. Length c. 44 mm, diameter c. 2 mm. C. 92 segments. Bodydepressed with a distinct creeping sole. Colouration; body an intense chestnut brown or maroonbecoming more greyish at the anterior and posterior ends, clitellum a bright bluish slate-grey.Clitellum xiii-xvi. First dorsal pore 9/10. Setae, c. 75 on vii and xx. Setal ring crowded ventrallywithout dorsal or ventral gaps (5aa = 5ab=yz = zz). Male pores simple, c. 0-15 body circumference apart. Female pore single. Spermathecal poressmall in 7/8/9, c. 0-20 body circumference apart. Genital markings (Fig. 29d) single, median, intersegmental at 17/18. Internal characters. Anterior septa present and delicate. Intestine simple, begins in xiv. Lateralhearts in x-xiii. Holandric, testes sacs paired, extending to the dorsal line in x and xi, seminal vesicles of xismall, enclosed in the testes sacs of that segment, those of xii larger, extending to the dorsal line.Spermathecae (Fig. 27h) paired in viii and ix. DISTRIBUTION. Borneo. MATERIAL EXAMINED. 1C (lacking most of the internal anterior anatomy and parts of the bodywall), Mt Damoes, 'Borneo' ( ? Kalimanton) ; Leiden 1811 (part of holotype of nieuwenhuisi).Gizzard, oesophagus, anterior portion of intestine, anterior male reproductive system and twofragments of body wall, data as above ; Hamburg v9306 (part of holotype of nieuwenhuisi). Planapheretima bambophila species-group DIAGNOSIS. Planapheretima with an intestine modified in the anterior region by the presence ofcaeca or glandular walls or both. DISTRIBUTION. Burma, China. SPECIES INCLUDED, arboricola, bambophila, continens, lacertina, tenebrica. REMARKS. The members of this species-group have caeca and/or glandular areas on the walls ofthe intestine; all occur on the mainland of Asia. In contrast, species outside of this species-group ACAECATE PHERETIMOID EARTHWORMS 75 (P. subulata species-group and its allies) have unmodified intestines and occur in the Indo-Australasian Archipelago. As discussed above (see numerical studies) the five species comprising this species-group appearto be closely related although there are both caecate and acaecate forms from edaphic and arbori-colous habitats. Despite the five species having apparently only convergent features in commonwith the other members of the genus, the generic diagnosis of Planapheretima has been widenedto accommodate them, since I do not propose to elevate the group to generic status on currentevidence. More morphological information is required while the genus Amynthas, with whichthis group seemingly has affinities, needs to be thoroughly revised. In addition to the species included in the bambophila species-group, two others, acidophila andjaoi, have been recorded from arboricolous habitats in Szechwan. As neither is adapted mor-phologically to an arboreal mode of life nor is either apparently related to any of the species ofthe bambophila species-group, it is proposed that they should remain in Amynthas where theywere placed by Sims & Easton (1972). Knowledge of the Chinese members of the bambophila species-group derives from the originaldescriptions of the species (Chen, 1946). Several discrepancies in the separation of the male andspermathecal pores exist in these accounts so caution needs to be taken when identifying speciesof this group. Marker characters of the species assigned to the bambophila species-group are given in Table 1 1 . Table 11 Marker characters of the members of the Planapheretime bambophilaspecies-group Species Spermathecal furrows Intestinal caeca Distribution Planapheretima continens (Chen, 1946) Pheretima continens Chen, 1946 : 95.Amynthas continens: Sims & Easton, 1972 : 235. DIAGNOSIS. Planapheretima with rudimentary intestinal caeca; spermathecal pores in furrows4/5/6/7 or 5/6/7/8. DESCRIPTION. External characters. Length 33-38 mm, diameter c. 2 mm. 94-102 segments. Bodycylindrical, creeping sole absent. Colouration ; grey on dorsal surface, pale ventrally, clitellum lightchocolate red. Clitellum ^xiii-xvii. First dorsal pore 1 1/12. Setae, 30-40 on Hi, 54-58 on vii, 52-55on xxv, setal ring slightly crowded ventrally with slight dorsal and ventral gaps (aa= l-2ab=l-5yz=zz\ Male pores on small penes which arise from circular porophores c. 0-33 body circumferenceapart. Female pore(s) not recorded. Spermathecal pores small in 5/6/7/8 or occasionally 4/5/6/7,c. 0-40 body circumference apart. Genital markings (Fig. 306) paired, presetal on ix slightly median to the line of the sperma-thecal pores. Internal characters. Septa 5/6-7/8 thickened, 8/9/10 absent, 10/11 membranous, 11/12-14/15thickened. Intestine begins in xvi with paired rudimentary caeca about one segment long (originnot recorded) and with glandular walls posterioriad to the caeca. Disposition of lateral heartsnot recorded. 76 E. G. E ASTON .'J. a 2mm f Fig. 30 Anterior ventral surface, diagnostic characters, (a) Planapheretima arboricola; (b) P.continens; (c) P. sera sp. nov. Dorsal pigmentation, (d) P. lacertina; (e) P. tenebrica. Spermatheca.(0 P- sera sp. nov. Holandric, testes sacs paired, those of x extending to the dorsal line, those of xi smaller, seminalvesicles small in xi and xii. Spermathecae (Fig. 27i) paired in vi-viii or occasionally v-vii.Description after Chen (1946). DISTRIBUTION. Szechwan, China. RECORDS. 2 specimens Mt Omei, Szechwan, China (types of continens). 2 specimens under moss,Changking, Szechwan, China (continens: Chen, 1946). Planapheretima arboricola (Rosa, 1890) Perionyx arboricola Rosa, 1890 : 119; Beddard, 1895 : 438; Michaelsen, 1900 : 209; Michaelsen, 19036 : 89; Stephenson, 1923 : 326; Gates, 1936a : 465; Gates, 1961 : 57; Gates, \912a : 141.Pheretima arboricola Gates, 1936a : 399; Gates, 1972a : 169.Planapheretima arboricola: Sims & Easton, 1972 : 233. DIAGNOSIS. Planapheretima with multiple intestinal caeca; spermathecal pores in furrows5/6/7/8/9. DESCRIPTION. External characters. Length c. 70 mm, diameter c. 5 mm. C. 1 10 segments. Bodydepressed, creeping sole on postclitellar segments becoming narrower posteriorly. Colouration ;dark green or reddish dorsally, pale yellow ventrally, clitellum violet grey. Clitellum xiv-xvi.First dorsal pore ? 5/6 or 11/12. Setae c. 72 on vii, c. 60 on xx. Setal ring crowded ventrally,lab=yz. ACAECATE PHERETIMOID EARTHWORMS 77 Male pores on large hemispherical porophores c. 0-18 body circumference apart. Female poresingle. Spermathecal pores small paired, intersegmental in 5/6/7/8/9, c. 0-26 body circumferenceapart. Genital markings (Fig. 30a) single, median, xviii. Internal characters. Anterior septa delicate, 8/9/10 absent. Intestine begins in xv with paired,lateral multiple caeca originating in xxvii, details of intestinal wall not recorded. Lateral heartsin x-xiii. Holandric, testes sacs single, ventral in x and xi, seminal vesicles large in xi and xii. Spermathe-cae (Fig. 27j) paired in vi-ix. Fig. 30a is an interpretation of the genital field based on the written description of Gates(1936). The holotype lacks genital markings. DISTRIBUTION. Burma. REMARKS. The holotype of Pheretima arboricola Gates (1936) was recorded as being in the MuseoCivico di Storia Naturale 'Giacomo Doria', Genoa (Reynolds & Cook, 1976). However, the speci-men (44017) proved to be the holotype of Perionyx arboricola Rosa (1890) which had originallybeen reported as having a gizzard in v and a holonephric excretory system. On re-examination itwas found that Rosa's description was inaccurate since the gizzard is in viii and the excretorysystem is micronephric, characters of the Pheretima group. Unfortunately the intestine waspoorly preserved so preventing the recognition of any intestinal structures important for specificdiagnosis within Planapheretima. It is assumed that caeca were once present in the holotype sinceGates (1936) described an otherwise identical earthworm, destroyed in Burma between 1942 and1945, which possessed these structures. [The paratype of Perionyx arboricola, Berlin 2270 (Rey-nolds & Cook, 1976 : 71) is a juvenile Perionyx of uncertain specific identity.] MATERIAL EXAMINED. 1C Lacking anterior intestine and most of oesophagus, on trees, especiallyin the axils of leaves, Cobapo, Mt Carin, Cheba or Biapo district, Burma, coll L Fea; Genoa44017 (holotype of arboricola Rosa, 1890). OTHER RECORDS. 1C Toungoo district, Burma (holotype of arboricola Gates, 1936). Planapheretima lacertina (Chen, 1946) Pheretima lacertina Chen, 1946 : 109.Planapheretima Sims & Easton, 1972 : 233. DIAGNOSIS. Planapheretima with rudimentary caeca; Spermathecal pores in furrows 5/6/7/8/9. DESCRIPTION. External characters. Length c. 81-82 mm, diameter 4-4-5 mm. 90-100 segments.Body depressed and concave ventrally, creeping sole not recorded. Colouration; dark chestnut orbrownish black pattern (Fig. 30d) on a bluish background. Clitellum xiv-xvi. First dorsal pore10/11. Setae, c. 72 on Hi, c. 78 on vi, c. 81 on ix, c. 72 on xxv, setal ring crowded ventrally(3-4ab=yz) dorsal and ventral gaps not recorded. Male pores in large glandular, circular depressions c. 0-33 body circumference apart. Femalepore(s) not recorded. Spermathecal pores small in 5/6/7/8, separation uncertain [either 0-33 or0-44 body circumference apart (see remarks under bambophila species-group)]. Genital markings, none recorded. Internal characters. All anterior septa present and delicate except for 6/7-8/9 which are slightlythickened. Intestine begins in xv with paired rudimentary lateral caeca restricted to xxvi, intes-tinal wall posterioriad to caeca glandular. Disposition of lateral hearts not recorded. Holandric, testes sacs single in x and xi, seminal vesicles large in xi, those of xii extending pos-teriorly to xiv. Spermathecae (Fig. 27k) paired in vi-ix. Description after Chen (1946). DISTRIBUTION. Szechwan, China. RECORDS. 2 specimens, among moss on bark of trees, Mt King-Fu, Szechwan, China, 2000 ft(types of lacertina). 78 E. G. EASTON Planapheretima tenebrica (Chen, 1946) Pheretima tenebrica Chen, 1946 : 93.Planapheretima tenebrica; Sims & Easton, 1972 : 233. DIAGNOSIS. Planapheretima with an intestine lacking caeca but with thickened walls in xxvi-xxxvi;spermathecal pores in furrows 5/6/7/8/9. DESCRIPTION. External characters. Length 35-60 mm, diameter 2-2-8 mm. C. 82 segments. Shapeof body and creeping sole not recorded. Colouration; three longitudinal reddish brown dorsalstripes (Fig. 30e) on a chocolate-coloured background, clitellum dark chocolate to brick red.Clitellum xiv-xvi, encroaching onto xiii and xvii. First dorsal pore 9/10. Setae, 46-50 on in,52-60 on ix, 50-52 on xix and xxv, setal ring crowded ventrally with dorsal and slight ventralgaps (aa=\-\-\ab\ zz = 2-2-5yz~). Male pores on circular porophores, separation uncertain [either 0-20 or 0-33 body circumferenceapart (see remarks under bambophila species-group)]. Female pore(s) not recorded. Spermathecalpores small in 5/6/7/8/9, separation uncertain (either 0-20 or 0-33 body circumference apart). Genital markings, none recorded. Internal characters. All anterior septa present and delicate. Intestine begins in xv, caeca absent,intestinal walls of xxvi-xxxvi thickened. Disposition of lateral hearts not recorded. Holandric, testes sacs of x paired but meeting ventrally, that of xi single ventral, seminal vesicleslarge in xi and xii extending posteriorly 5-7 segments. Spermathecae (Fig. 271) paired in vi-ix. Description after Chen (1946). DISTRIBUTION. Szechwan, China. RECORDS. 9 specimens, Mt Omei, Szechwan, China, 5000 ft (holotype and paratypes of tenebrica');1 specimen in sandy ground under stone near creek, Nan-Chuan-Hsein, Szechwan, China (para-type of tenebrica). Planapheretima bambophila (Chen, 1946) Pheretima bambophila Chen, 1946 : 86.Planapheretima bambophila: Sims & Easton, 1972 : 233. DIAGNOSIS. Planapheretima with an intestine lacking caeca but with thickened walls in xxii-xxxviii; spermathecal pores in furrows 7/8/9. DESCRIPTION. External characters. Length 40-55 mm, diameter 3-4 mm. 88-94 segments. Bodydepressed with a glandular creeping sole on viii-ix and from the male pores to the posterior end ofthe body. Colouration; purplish brown dorsally, pale ventrally. Clitellum xiv-xvi. First dorsalpore 10/11. Setae, c. 84 on x, c. 54 on xix, c. 52 on xxv, c. 44 on xl, setal ring crowded ventrally,especially on the creeping sole (ab = 0-6yz on xix). Male pores simple within the creeping sole, c. 0-25 body circumference apart. Female pore single.Spermathecal pores small in 7/8/9, c. 0-25 body circumference apart. Genital markings, none recorded. Internal characters. All anterior septa present and delicate ; intestine begins in xv, caeca absentbut walls thickened and forming pouches in xxii-xxix and less conspicuously in xxx-xxxviii.Disposition of lateral hearts not recorded. Holandric, testes sacs small single ventral in x and jci, seminal large in xi and xii, extendinganteriorly to we and posteriorly to xvii. Spermathecae (Fig. 27m) paired in viii and ix. Description after Chen (1946). DISTRIBUTION. Szechwan, China. RECORDS. 3 specimens on bushy bamboos, Kiu-Lac-Tung, Mt Omei, Szechwan, China (types ofbambophila). METAPHERET1MA Michaelsen, 1928 Perichaeta (part): Beddard, 1895 : 388.Amynthas (part): Beddard, 1900a : 612. 79 Pheretima (part): Michaelsen, 1900 : 234.Pheretima (Pheretima) (part): Michaelsen, 19280 : 8.Pheretima (Metapheretima) (part) Michaelsen, 1928a : 8.Metapheretima (part): Sims & Easton, 1972 : 205, 233.Pheretima (Polypheretimd) (part): Michaelsen, 19346 : 15.Ephemitra Sims & Easton, 1972 : 203, 232. TYPE SPECIES. Perichaeta neoguinensis Michaelsen, 1892, original designation. DIAGNOSIS. Megascolecidae with an oesophageal gizzard in viii, intestinal caeca and gizzardsabsent. Body cylindrical, setae never excessively crowded ventrally, creeping sole absent. Malepores lacking porophores, occasionally on slim penes which may be within copulatory pouches.Crescentic genital markings associated with the male pores on mature individuals of most species.Spermathecal pores small or large, spermathecal diverticula variable in structure and origin. DESCRIPTION. Body cylindrical, creeping sole absent. Clitellum annular, usually restricted to threesegments (xiv-xvi), rarely extending over more (xiii, xvii). First dorsal pore between 8/9 and 13/14.Setae perichaetine, never excessively crowded ventrally, dorsal and ventral gaps small (aa = l-2ab,zz= \-2yz). Lateral hearts in x-xii and sometimes xiii. Oesophagus with a well-developed gizzard in viii and occasionally a pair of dorsal pouches inx-xi, calciferous glands absent. Intestine usually begins in xv or xvi but may begin more posteriorlyin xx ; simple, lacking caeca, gizzards and glandular walls. Usually holandric, occasionally metandric, rarely proandric. The testes of each segment areenclosed in a single or paired sacs which are usually small and discrete, occasionally enclosingthe anterior seminal vesicles. One pair of seminal vesicles in the segment directly posterior toeach pair of testes. Prostates racemose. Paired, combined male and prostatic pores on the ventralsurface of xviii in the setal ring. Male pores occasionally on slim penes, often within copulatorypouches; porophores absent. Ovaries free in xiii. Oviducts lead to single or closely paired, midventral, equatorial pore(s) onxiv. Spermathecae differentiated into duct and ampulla, diverticula variable in structure andorigin. Spermathecae usually arranged in pairs, infrequently in paired batteries of up to 8 Sperma-thecae ; in one to five adjacent segments between v and ix. Spermathecal pores small or slit-like,always intersegmental. Genital markings of the discrete type or annular ridges; diffuse markings absent. In mostspecies crescentic markings are closely associated with the male pores. In those species where theyare absent the male pore may be surrounded by a pigmented annulus. The genital markings areusually arranged in pairs, they are never random or numerous (cf. Polypheretima bifaria andpatae species-groups). The glandular tissue associated with the genital markings is restricted to thebody wall and never invades the coelom. DISTRIBUTION. (Fig. 7.) North and south east New Guinea, New Britain, Lombok. Species may beindigenous in the Carolines, Solomon Islands and New Hebrides. NUMERICAL STUDIES. The taxa of the genus Metapheretima listed in Table 1 (7-36) were investi-gated numerically utilizing characters 3-29 in Table 2. Distributional data (characters 1 and 2)were not employed since the majority of taxa of Metapheretima are known only from New Guineaand the autochthony or otherwise of populations from elsewhere is uncertain. The configuration of the taxa with the first and second vectors of the principal co-ordinatesanalysis as axes to which the MST with graded linkages has been added is shown in Fig. 31. Threedivisions, indicated by circular, triangular and square symbols, may be recognized together withan isolated taxon jocchana (36) indicated by a star-shaped symbol. Unlike the divisions recognized within the other acaecate genera reviewed above, those ofMetapheretima form more diffuse configurations. Most of the taxa with simple male pores areaccommodated in Division I. Species of this division usually have four to five thecal segments,ectal spermathecal diverticula and the male pores never possess annular ridges. Taxa with male pores on penes are assigned to Divisions II and III ; those with several thecalsegments and ectal spermathecal diverticula form Division II while those with one or two thecal 80 E. G. E ASTON J 24 .15 28 ///.35 26 4 - ' ,27 Fig. 31 Principal co-ordinates analysis of 30 species here assigned to Metapheretima (7-36 ofTable 1): the configuration of species with the vectors corresponding to the first and second latent roots. The linkages of the added MST are graded to indicate percentage similarities; , +95%; , 90-95%; , -90%. Three major assemblages and an isolated species are recognized: Division I - circular symbols (closed circles - bulmeri species-group, open circles - neoguinensis species-group). Division II - triangular symbols (durendali species-group).Division III -square symbols (pinakensis species-group).Metapheretima jocchana - star-shaped symbol. segments and ental spermathecal diverticula form Division III. Annular ridges are often associ-ated with the male pores of taxa included in Division III. The isolated taxon jocchana (36) hassimple male pores encircled by annular ridges, a single thecal segment and numerous entaldiverticula on the spermathecae. Division I comprises two clusters, the members of each are denoted by closed or open circularsymbols. Species 1 1 (pallens) has been included in the cluster with closed circular symbols becausefive of its six nearest neighbours belong to this group although it is linked by the MST to the othercluster. Species forming the two clusters may be distinguished by the form of the spermathecaldiverticula. The cluster formed by closed circular symbols comprise taxa with simple diverticula,the bulmeri species-group ; the other cluster with open circular symbols consist of the species withmultiocular spermathecal diverticula, the neoguinensis species-group. The inclusion of the speciessembaluensis (15) in Division I needs comment. Although its nearest neighbours belong to DivisionIII (square symbols) it is assigned to Division I (circular symbols) since it lies intermediatelybetween the two divisions and possesses the marker characters of Division I. The two species of Division II form the durendali species-group while those of Division IIIcomprise the oinakensis species-group. ACAECATE PHERETIMOID EARTHWORMSTable 12 Phenetic classification and checklist of the genus Metapheretima 81 DIVISION I bulmeri species-group \jieoguinensis species-group DIVISION II iurendali species-group DIVISION III oinakensis species-group- arensi (7)bulmeri (8)carolinensis (9)elrondi (10)lindiaepollens (11)pickfordi (12)queribunda (13)quinqueremis (14)sembaluensis (15)sentanensis (16)simsi (17)sola (18)speiseri (19)triciae (20)Jrukensis (21) deirdriaeloriae (22)neoguinensis (23)septocta (24).sucklingensis (25) \durendali (26)-[ excalaberi (26) andurili (28)<fori7 (29)glamdringi (30) oinakensis (32)orcrista (33)parmata (34)jri>z/ (35)tawarinensis 'jocchana (36) Numbers in parentheses indicate taxa assessed in numerical studies (see Figs 6 and 31). Metandry or Holandry appears to be of little taxonomic value in the recognition of the species-groups within the genus Metapheretima. The importance of the number and distribution of testesin members of this genus is in contrast to the numerical study of the genus Polypheretima wherethese characters proved to be valuable indicators. A summary of the phenetic classification based on this numerical study is given in Table 12. Key to the species of the genus Metapheretima 1 First spermathecal pores in furrow 4/5First spermathecal pores in furrow 5/6First spermathecal pores in furrow 6/7First spermathecal pores in furrow 7/8 2 Two thecal segmentsFour thecal segmentsFive thecal segments 3 Holandric; genital markings as Fig. 42aMetandric; genital markings as Fig. 34a 2 12 19 21 3 durendali (part) (p. 105)4 excalaberi (p. 104)arensi (p. 83) 82 E. G. EASTON 4(2) Proandric or holandric ............ 5 Metandric ............... 8 5 Setal numbers very low (less than 40 on vii even in large specimens) polythecal bulmeri (p. 84)Setal numbers intermediate (bithecal) ......... 6 Setal numbers very high (more than 100 on vii even in small specimens) bithecal sentanensis (p. 88) 6 Preclitellar genital markings single, spermathecal pores c. 0-50 body circumference apart pickfordi 1 (p. 91) Preclitellar genital markings paired, spermathecal pores 0-26-0-40 body circumferenceapart .............. 7 7 Testes in x only queribunda (p. 90) Testes in x and xi speiseri (part) (p. 92) 8(4) Spermathecal diverticulum simple 9 Spermathecal diverticula multilocular loriae (p. 99) 9 Spermathecal diverticulum short and ental in origin . . . quinquerimis (p. 85) Spermathecal diverticulum long and ectal in origin . . . . . . . 10 10 Bithecal; preclitellar genital markings single or absent . . . . . . 11 Polythecal; preclitellar genital markings paired ...... Undue (p. 89) 1 1 Postclitellar genital markings single (preclitellar genital markings absent; . simsi (p. 87)Postclitellar genital markings paired (preclitellar genital markings single) pickfordi 1 (p. 91) 12(1) One or two thecal segments andurili (p. 109) Three thecal segments ............ 13 Four thecal segments ............ 15 13 Spermathecal pores numerous on dorsal surface .... carolinensis (p. 96)Spermathecal pores paired on ventral surface . . . . . . . . 14 14 Male pores simple: genital markings as Fig. 39a ..... trukensis (p. 96)Male pores on penes within copulatory pouches ; genital markings as Fig. 42b durendali (part) (p. 105)15(2) Holandric 16 Metandric .............. 17 16 Preclitellar genital markings on vii-ix ...... speiseri (part) (p. 92) Preclitellar genital markings on ix-xi ....... elrondi (p. 93) 17(5) Spermathecal diverticulum simple .......... 18 Spermathecal diverticulum multilocular ...... neoguinensis (p. 99) 18 Setal numbers low (less than 40 on vii even in large specimens) . . . sola (p. 93) Setal numbers high (more than 100 on vii even in small specimens) . . triciae (p. 94)19(1) One or two thecal segments durendali (part) (p. 105) Three thecal segments ............ 20 20 Spermathecal diverticulum simple speiseri (part) (p. 92) Spermathecal diverticulum multilocular sucklingensis (p. 102) 21(1) One thecal segment 22 Two thecal segments 26 22 Spermathecal diverticulum simple 23 Spermathecal diverticulum multilocular ....... septocta (p. 103) Spermathecal diverticulum numerous (Fig. 33p) ..... jocchana(p. 113) 23 Proandric glamdringi (p. 113) Holandric 24 Metandric .............. 25 24 Postclitellar genital field as Fig. 43a tawarinensis (p. 106) Postclitellar genital field as Fig. 44b stingHp. 109) Postclitellar genital field as Fig. 44c oinakensis (p. Ill) Postclitellar genital field as Fig. 45a orcrista (p. 1 1 2) Postclitellar genital field as Fig. 45b parmata (p. 112) 25(23) Genital markings as Fig. 43b (spermathecal pores c. 0-20 body circumference apart) kilii (p. 107)Genital markings as Fig. 43c (spermathecal pores c. 0-37 body circumference apart) dorii(p. 108)26(21) Holandric sembaluensis (p. 98) ACAECATE PHERETIMOID EARTHWORMS 83 27 Spermathecal diverticulum simple ........ pollens (p. 98) Spermathecal diverticulum multilocular ....... deirdrae (p. 102) 1 The unique holotype of pickfordi is damaged and may be holandric or metandric, it has therefore been keyed outtwice to allow for either condition. Metapheretima bulmeri species-group DIAGNOSIS. Metapheretima with simple male pores lacking associated glandular ridges. Sperma-thecal diverticula simple. SPECIES INCLUDED, arensi, bulmeri, carolinensis, elrondi, lindiae, pallens, pickfordi, queribunda,quinqueremis, sembaluensis, sentanensis, simsi, sola, speiseri, triciae, trukensis. DISTRIBUTION. Species occur in all parts of the generic range. REMARKS. The bulmeri species-group includes all the species of the genus Metapheretima possess-ing simple male pores with the exception of those which additionally have multilocular ornumerous Spermathecal diverticula. The latter are assigned to the neoguinensis species-group andtojocchana respectively. The results of the numerical studies failed to reveal any subassemblageswith high percentage similarities indicative of subdivisions within the bulmeri species-group. The inter-relationships of the species recorded from the New Hebrides and Solomon Islandsare far from certain. Although each taxon is treated here as a separate species, it is probable thatwhen further material becomes available they will be found to be conspecific. Several of the species included in this group have the oesophagus modified in x and/or xi toform dorsal or dorsolateral pouches. Considerable variation in the degree of development of thesestructures may be encountered within individuals of a species. The presence of these pouches wasutilized as a diagnostic generic character (Ephemitra Sims & Easton, 1972). The development ofoesophageal pouches among the species of this group may to some extent be functionally cor-related with the development of metandry since the enlargement of the oesophagus in jc limits thespace available for testes and testes sacs. Marker characters of the species included in the bulmeri species-group are given in Table 13. Metapheretima arensi (Ude, 1932) Pheretima (Metapheretima) arensi Ude, 1932 : 168.Metapheretima arensi: Sims & Easton, 1972 : 233. DIAGNOSIS. Metapheretima with simple male pores; paired Spermathecal pores about one thirdof the body circumference apart in furrows 4/5/6. Metandric. DESCRIPTION. External characters. Length 90-110 mm, diameter, 3-5-4 mm. 125-154 segments.Clitellum xiv-xvi. First dorsal pore 11/12. Setae, 140-150 on vii, 75-95 on xx, setal ring regularwith ventral gaps (aa = 2ab = 2yz = 2zz). Male pore simple, c. 0-20 body circumference apart. Female pores paired. Spermathecal poressmall, paired in 4/5/6, c. 0-30 body circumference apart. Genital markings (Fig. 34a) single, median presetal on ix and x, paired, presetal in line with themale pores on xvii and xix. Internal characters. Septa 5/6/7/8 thickened, 8/9 membranous, 9/10 absent, 10/11 thickened.Oesophagus with small dorsal pouches in x-xii. Intestine begins in xv. Lateral hearts in x-xiii. Metandric, testes sacs small, paired ventral in xi, seminal vesicles large, extending to the dorsalline in xii. Spermathecae (Fig. 32a) paired in v and vi. DISTRIBUTION. New Britain. MATERIAL EXAMINED. Previously reported. 3C, 1A Mejin bay, New Britain; Hamburg v3429(syntypes of arensi) 2 other specimens from this series have been re-identified as Pithemera pacifica(Beddard, 1899); Hamburg v!0032. 1A Aid river, New Britain; Hamburg v3458 (syntype ofarensi). 1C Lieblide Island, New Britain; Hamburg v!0031 (syntype of arensi). 84 E. G. EASTON k I m n o Fig. 32 Spermathecae. (a) Metapheretima arensi; (b) M. bulmeri; (c) M. lindiae sp. nov.; (d) M.quinqueremis sp. nov.; (e) M. simsi sp. nov.; (f) M. sentanensis; (g) M. queribunda', (h) M, speiseri;(i) M. elrondi sp. nov.; (j) M. so/a sp. nov.; (k) M. fr/c/ae sp. nov.; (1) M. trukensis', (m) M.carolinensis\ (n) M. sembaluensis; (o) M. pollens. All scales 0-5 mm. record. 1C Tu Island, New Britain. This specimen was removed from a series of Pithemerasedgewicki typica: Ude, 1932; Hamburg v3470. Metapheretima bulmeri (Gates, 1970) Pheretima bulmeri Gates, 19706 : 386.Metapheretima bulmeri: Sims & Easton, 1972 : 233. DIAGNOSIS. Metapheretima with simple male pores; numerous spermathecal pores in pairedbatteries about one quarter of the body circumference apart in furrows 4/5/6/7/8/9. Holandric.Setal numbers low (cf. kinabaluensis Fig. 2) diverticula simple, ectal. DESCRIPTION. External characters. Length 200-340 mm, diameter 10-14 mm. 105-129 segments.Clitellum xiv-xvi. First dorsal pore 12/13. Setae, c. 42 on vii, c. 50 on xx, setal ring regular withdorsal gaps (aa = ab=yz = Q-5zz). Male pores simple, c. 0-20 body circumference apart. Female pore single. Spermathecal poressmall, numerous in paired batteries of up to 7 pores in 4/5/6/7/8/9, c. 0-28 circumference apart. Genital markings (Fig. 34b), only those diagnostic of the genus. Internal characters. Septa 4/5-7/8 membranous, 8/9/10 absent, 10/11 membranous, 11/12-14/15slightly thickened. Oseophagus unmodified. Intestine begins in xv. Lateral hearts in x-xii. Holandric, testes sacs small, paired in x and xi, seminal vesicles extending to the dorsal line inxi and xii. Pseudoseminal vesicles in xiii. Spermathecae (Fig. 32b), numerous, arranged in pairedbatteries of up to 7 spermatheca in v-ix. ACAECATE PHERETIMOID EARTHWORMS 85 k I m n o p Fig. 33 Spermathecae. (a) Metapheretima loriae; (b) M. neoguinensis\ (c) M. sucklingensis sp. nov.;(d) M. dierdrae sp. nov.; (e) M. septocta sp. nov.; (f) M. excalaberi sp. nov.; (g) M. durendalisp. nov.; (h) M. tawarinensis; (i) M. kilii sp. nov.; (j) M. dorii sp. nov.; (k) M. andurili sp. nov.;(1) M. stingi sp. nov.; (m) M. oinakensis; (n) M. orcrista sp. nov.; (o) M. glamdringi sp. nov.; (p)M. jocchana. All scales 0-5 mm. DISTRIBUTION. North east New Guinea. MATERIAL EXAMINED. Previously reported. 2C Schrader range, Papua New Guinea; Sydney v4259(syntypes of bulmeri). I am indebted to Dr B. G. M. Jamleson, University of Queensland, forexamining the types and for making drawings on which the figures of the genital markings andspermathecae are based.New record. 1C, 1A Schrader range, Papua New Guinea; BMNH 1976.2.1-2. Metapheretima quinqueremis sp. nov. DIAGNOSIS. Metapheretima with simple male pores; paired spermathecal pores about one fifth ofthe body circumference apart in furrows 4/5/6/7/8/9. Metandric. Setal numbers intermediate(cf. elongata, Fig. 2). Spermathecal diverticula simple, ectal. DESCRIPTION. External characters. Length 86-122 mm, diameter 4-5 mm. 73-97 segments.Clitellum xiv-xvi. First dorsal pore 12/13. Setae, 40-44 on vii, 41-44 on xx, setal ring regularwith dorsal and ventral gaps (aa=l-5ab=l-5yz = zz). Male pores simple c. 0-20 body circumference apart. Female pores paired. Spermathecal poressmall, paired, in 4/5/6/7/8/9, c. 0-20 body circumference apart. Genital markings (Fig. 35a), large, paired, presetal slightly median to the spermathecal pores onvi-ix, in line with the male pores on xvii, xix-xx. 86 E. G. EASTON ACAECATE PHERETIMOID EARTHWORMS 87 a b c Fig. 34 Anterior ventral surface, diagnostic characters, (a) Metapheretima arensi; (b) M. bulmeri; (c) M. lindiae sp. nov. Internal characters. Septa 4/5-12/13 present and membranous. Intestine begins in xv. Lateralhearts in x-xii. Metandric, testes sacs small, paired, ventral in xi, seminal vesicles large, extending to the dorsalline in xii. Pseudoseminal vesicles prominent in xiv . Spermathecae (Fig. 32d) paired in v-ix. DISTRIBUTION. South east New Guinea. MATERIAL EXAMINED. 25C, 1A Mt Suckling, Papua New Guinea, 9 46' S, 149 00' E, coll W HEwer 1972; BMNH 1976.4.30-54 (syntypes of quinqueremis}. 1C Gentle ridge, Bismarck range,Eastern Highland district, Papua New Guinea, 5 57' S, 145 15' E, 2500 m, coll D R Kershaw14 Jul 1971; BMNH 1976.5.116. Metapheretima simsi sp. nov. DIAGNOSIS. Metapheretima with simple male pores; spermathecal pores about one third of thebody circumference apart in furrows 4/5/6/7/8/9. Metandric. Setal numbers intermediate (cf.elongata, Fig. 2). Postclitellar genital markings single, median, presetal. Spermathecal diverticulasimple, ectal. DESCRIPTION. External characters. Length c. 36mm, diameter c. 1-5 mm. C. 118 segments.Clitellum xiv-xvi. First dorsal pore not detectable in preclitellar furrows. Setae, c. 41 on vii, c. 30on xx, setal ring regular (aa = ab=yz = zz). 88 E. G. EASTON Male pores simple, c. 0-24 body circumference apart. Female pores paired. Spermathecal poressmall, paired, in 4/5/6/7/8/9, c. 0-35 body circumference apart. Genital markings (Fig. 35b) oval, single, presetal, median on xvii-xx. Internal characters. Septa 6/7/8 thickened, 8/9-13/14 membranous. Oesophagus simple. Intestinebegins in xv. Lateral hearts in x-xii. Metandric, testes sacs large, paired with dorsal link in xi, seminal vesicles extending to thelateral line in xii. Spermathecae (Fig. 32e) paired in v-ix. DISTRIBUTION. New Guinea. REMARKS. The possession of single median postclitellar genital markings distinguishes this speciesfrom all other members of the genus Metapheretima with five thecal segments. MATERIAL EXAMINED. 1C Woitape, Goilala, Papua New Guinea, 8 22' S, 147 03' E, altitude1500 m, coll Griffiths 2 Jul 1972; BMNH 1976.10.19 (holotype of simsi). Metapheretima sentanensis (Cognetti, 1911) Pheretima sentanensis Cognetti, 1911 : 5; Cognetti, 1912 : 551. Ephemitra sentanensis: Sims & Easton, 1972 : 181, 204, 232. Pheretima myritchasta (sic) Cognetti, 1911 : 4. Pheretima myriochaeta: Cognetti, 1912 : 549. Ephemitra myriochaeta: Sims & Easton, 1972 : 181, 232. Pheretima ardita Cognetti, 1914 : 353. Pheretima (Pheretima) ardita: Ude, 1932 : 145. Ephemitra ardita: Sims & Easton, 1972 : 180, 232. Pheretima tamiensis Ude, 1924 : 84. Pheretima (Pheretima) tamiensis: Ude, 1932 : 136. Metapheretima tamiensis: Sims & Easton, 1972 : 233. DIAGNOSIS. Metapheretima with simple male pores ; paired Spermathecal pores about one quarterof the body circumference apart in furrows 4/5/6/7/8/9. Holandric. Setal numbers high (Fig. 2).Spermathecal diverticula simple, ectal. DESCRIPTION. External characters. Length 25-145 mm, diameter 1-5-5 mm. 90-212 segments.Clitellum xiv-xvi. First dorsal pore occasionally 8/9/10 but usually 12/13. Setae, 100-300 on vii,50-128 on xx, setal ring regular but occasionally with displaced setae forming double rings(aa =ab=yz = zz). Male pores simple, c. 0-20-0-27 body circumference apart. Female pore single, rarely paired.Spermathecal pores small, paired, 4/5/6/7/8/9, c. 0-20-0-29 body circumference apart. Genital markings (Fig. 35c, d) paired, median to the line of the Spermathecal pores, presetalon viii-x and occasionally postsetal on viii and ix, in line with or slightly median to the male pores,presetal on xvii, xix-xxv. Internal characters. Septa 5/6/7/8 thickened, 8/9 membranous, 9/10 membranous or absent, 10/11membranous, 11/12 membranous or absent, 12/13/14 membranous. Paired dorsal oesophagealpouches in x. Intestine begins in xvi. Lateral hearts in x-xii. Holandric, testes sacs paired in jc, single in xi, extending to the dorsal line, seminal vesicles inxi and xii, those of xi enclosed in the testes sacs. Pseudoseminal vesicles in xiii and occasionallyxiv. Spermathecae (Fig. 32f) paired in v-ix. DISTRIBUTION. New Guinea. REMARKS. The types of ardita, myriochaeta and tamiensis differ from the type series of sentanensisprincipally in segment size and setal numbers. The species tamiensis was originally described ashaving four pairs of Spermathecae but a re-examination of the single extant syntype revealed thepresence of five pairs. In view of the correlation between setal and segmental development thesedifferences do not appear to be taxonomically significant. ACAECATE PHERETIMOID EARTHWORMS 89 Most specimens examined had only presetal genital markings associated with the spermathecalpores, both pre- and postsetal markings were present in a minority which additionally appeared tohave slightly lower setal numbers, but no conclusive correlations could be established. MATERIAL EXAMINED. Previously reported. 13C, 3 A Near lake Sentani, Jaga (Jocchana), WestIrian; Amsterdam Vol. 301 (syntypes of sentanensis). 3 other specimens from this series are atTurin (01. 193), they were not examined. 1C Near Tawarin river, west of Mt Cyclops, West Irian;Amsterdam Vol. 289 (holotype of myriochaetd). 1C Bivouac 'Zoutbron' on river Begowre, WestIrian, 3 1' 13" S, 140 57' 30" E; Leiden 1827 (holotype of arditd). 2C, 3A Tami, Papua NewGuinea; Berlin 6464 (ardita: Ude, 1932). 1C Tami, Papua New Guinea; Berlin 6462 (syntype oftamiensis). New records. 1C, 12A Kaironk valley, Simbai region, Madang district, Papua New Guinea,1750-1950 m, coll R N H Bulmer 8-12 Nov 1973; BMNH 1976.2.8-20. 6A Dense clay with denseorganic matter and thin grass cover, side of road adjacent to coffee plantation, Amahab villagec. 16 km west of Maprik, Sepik district, Papua New Guinea, coll J W Copland 12 Nov 1971;BMNH 1976.3.100-105. 2A Dry to moist loam covered by grass and small trees, bank of river,Sepik Plains Livestock Station, Urimo, Sepik district, Papua New Guinea, coll J W Copland1971 ; BMNH 1976.3.106-107. 10A Moist medium to heavy dark loam with considerable organiccontent covered by a mat of paspalum, bank of small creek running through No. 12 paddock,Sepik Plains Livestock Station. Urimo, Sepik district, Papua New Guinea, coll J W Copland11 Nov 1971; BMNH 1976.3.108, 109-118. 13C, 8A 15 cm layer of black soil over sandy soilcultivated for gardens, halfway down hill to creek, Department of Agriculture, Stock and FisheriesPiggery, Goroka, Eastern Highlands, Papua New Guinea, coll J W Copland 13 Oct 1971 ; BMNH1976.3.87-96, 119-129. 1C, 2A Dark sandy loam covered by light vegetation, 120-150 m aboveNupa village, c. 24 km east of Goroka, Eastern Highlands, Papua New Guinea, coll J W Copland1971; BMNH 1976.1.97, 98-99. 6C, 8A DASF Piggery, Goroka, Papua New Guinea, coll J WCopland 13 Oct 1971; BMNH 1977.1.78-81, 141-150. 1C, 1A Bank of creek, DASF Piggery,Goroka, Eastern Highlands, Papua New Guinea, coll J W Copland 23 Aug 1972; BMNH1977.1.100-101. 7C, 1A Locality as above; coll J W Copland 1 Sep 1971; BMNH 1977.1.68-75.1C Nupa village, c. 24 km east of Goroka, Eastern Highlands, Papua New Guinea, coll J W Cop-land 13 Oct 1971 ; BMNH 1977.1.60. 14C, 25A Locality as above, coll J W Copland 31 Aug 1971 ;BMNH 1977.1.102-140. 3C, 1A Moist dense mixture of peat and soil, very rich in humus, LandResettlement Scheme (area drained 3 years prior to collection), Kendig, Mt Hagen, WesternHighlands, Papua New Guinea, coll J W Copland 1971; BMNH 1976.3.73-76. 3C, 1A DASFstation, Kendig, Mt Hagen, Western Highlands, Papua New Guinea, coll J W Copland 15 Nov1971; BMNH 1977.1.61-63. 3C Moist dark loam of moderate to high organic content, slopingplot being prepared for Kaukau, on boundary of Webag, Mt Hagen, Western Highlands, PapuaNew Guinea, coll J W Copland 16 Nov 1971 ; BMNH 1976.3.77-78, 79. 9C, 2A Local governmentcouncil piggery, west of Webag, Mt Hagen, Western Highlands, Papua New Guinea, coll J WCopland 16 Nov 1971; BMNH 1976.3.80-86, 1977.1.64-67. 2C Webag, Mt Hagen, WesternHighlands, Papua New Guinea, coll J W Copland 16 Nov 1971; BMNH 1977.1.76-77. 15C, 3AKasena, Papua New Guinea, coll J W Copland 25 Aug 1972; BMNH 1977.1.82-99. 2C, 1AMadang district, Papua New Guinea, coll R. Phipps; BMNH 1976.8.33-35. Metapheretima lindiae sp. nov. DIAGNOSIS. Metapheretima with simple male pores; numerous spermathecal pores in pairedbatteries about one fifth of the body circumference apart in furrows 4/5/6/7/8/9. Setal numbershigh (cf. sentanensis, Fig. 2). Spermathecal diverticula simple, ectal. DESCRIPTION. External characters. Length 54-60 mm, diameter c. 1-5 mm. C. 105-143 segments.Clitellum xiv-xvi. First dorsal pore 11/12. Setae, 94-100 on vii, 34-49 on xx, setal ring regular Male pores simple c. 0-22 body circumference apart. Female pore(s) not detected. Spermathecalpores small, numerous, arranged in paired batteries of 1-4 in 4/5/6/7/8/9, batteries c. 0-23 bodycircumference apart. 90 E. G. EASTON .< -i- abed Fig. 35 Anterior ventral surface, diagnostic characters, (a) Metapheretima quinqueremis sp. nov. ;(b) M. 5/W5/ sp. nov.; (c) M. sentanensis, syntypic individual; (d) M. sentanensis, varient individual. Genital markings (Fig. 34c) paired, presetal on ix median to the line of the spermathecal pores,on xvii, xx-xxiii in line with the male pores. Internal characters. Septa 5/6/7/8 thickened, 8/9 membranous, 9/10 not detected, 10/11-13/14slightly thickened. Oesophagus simple. Intestine begins in xv. Lateral hearts in x-xii. Metandric, testes sacs large, paired, extending to the dorsal line in xi, seminal vesicles large,extending to the dorsal line in xii, Pseudoseminal vesicles small in xiii and xiv. Spermathecae(Fig. 32c) numerous in paired batteries of 1-4 Spermathecae in v-ix. DISTRIBUTION. New Guinea. MATERIAL EXAMINED. 2C Madang district, Papua New Guinea 5 14' S, 145 45' E, coll R Phipps;BMNH 1976.8.1-2 (syntypes oUindiae). Metapheretima queribunda (Gates, 1958) Pheretima queribunda Gates, 1958 : 25.Metapheretima queribunda: Sims & Easton, 1972 : 233. DIAGNOSIS. Metapheretima with simple male pores ; paired spermathecal pores about one third ofthe body circumference apart in furrows 4/5/6/7/8/9. Proandric. DESCRIPTION. External characters. Length 75-80 mm, diameter 4-6 mm. 120-135 segments.Clitellum xiv-xvi. First dorsal pore 12/13. Setae, 96-120 on vii, c. 86 on xx, setal ring regular withventral gaps on postclitellar segments (aa ACAECATE PHERETIMOID EARTHWORMS 91 a b c Fig. 36 Anterior ventral surface, diagnostic characters, (a) Metapheretima queribunda;(b) M. pickfordi; (c) M. speiseri. Male pores simple, c. 0-24 body circumference apart. Female pores paired. Spermathecal poressmall, paired in 4/5/6/7/8/9, c. 0-35 body circumference apart. Genital markings (Fig. 36a) paired, presetal, slightly lateral to the spermathecal pores onvi-ix, in line with the male pores on xvii, xix-xxii. Internal characters. Septa 5/6/7/8 thickened, 8/9 membranous or absent, 9/10 absent, 10/11/12/13membranous. Intestine begins in xv. Lateral hearts in x-xii. Proandric, testes sacs paired, extending to the lateral line in x, single, extending to the dorsalline in xi (but lacking testes), seminal vesicles small, in xi enclosed in the testes sacs and xii.Pseudoseminal vesicles absent. Spermathecae (Fig. 32g) paired in v-ix. DISTRIBUTION. Solomon Islands. REMARKS. M. queribunda is noteworthy in that, although the posterior pair of testes are absent,the testes sacs of xi and the seminal vesicles of xii remain. Because of this condition it may beconfused with the holandric species of the bulmeri species-group. MATERIAL EXAMINED. Previously reported. 1C Gaudalcanal, Solomon Islands; New York 3505(holotype of queribunda). New record. 1C Under log, Russell Island, Solomon Islands, 15 m; coll R A Lever Feb 1934;BMNH 1935.1.18.1. Metapheretima pickfordi (Gates, 1957)Pheretima pickfordi Gates, 1957 : 18; Lee, 1969 : 4. 92 E. G. EASTON Metapheretima pickfordi: Sims & Easton, 1972 : 231.IPerichaeta loriae: Beddard, 1899 : 185 (non Rosa, 18986 : 61). DIAGNOSIS. Metapheretima with simple male pores; paired spermathecal pores about half of thebody circumference apart in furrows 4/5/6/7/8/9. Setal numbers high (cf. sentanensis, fig. 2).Spermathecal diverticula simple, ectal. DESCRIPTION. External characters. Length c. 26-28 mm, diameter c. 3 mm. C. Ill segments.Clitellum xiv-^xvi. Dorsal pores not recognized in preclitellar furrows. Setae, 80-90 on vi, c. 40on xx, setal ring with small dorsal and ventral gaps. Male pores simple, 'well lateral to the midventral line'. Female pores paired. Spermathecalpores paired in 4/5/6/7/8/9, c. 0-50 body circumference apart. Genital markings (Fig. 36b) presetal, single, median on vii-ix, paired, extending laterally as faras the male pores on xvii, xix-xxiii. Internal characters. Anterior septa delicate, 8/9 present, 9/10/11 not recognized. Intestine beginsin xv. Last lateral hearts in xii. Probably metandric, testes sacs single in xi, seminal vesicles small in xii. Spermathecae, pairedin v-ix, ampulla elongate, duct short, diverticula slightly longer than main chamber. Description after Gates (1957); Fig. 36b is an interpretation of the genital field based on Gates'swritten description. DISTRIBUTION. Solomon Islands. REMARKS. It is uncertain whether M. pickfordi is holandric or metandric. Gates (1957) could notrecognize the testes in x because of the decomposed condition of the type series and Lee (1969)did not comment on the condition of the testes in the specimens he examined. RECORDS. 1C, 1A Coconut grove, Lavanggu, Rennell Island, Solomon Islands (types of pickfordi).Guadalcanal (pickfordi: Lee, 1969). Metapheretima speiseri (Michaelsen, 1913) Pheretima speiseri Michaelsen, 19136 : 263.Pheretima (Pheretima) speiseri: Pickford, 1929 : 493.Planapheretima speiseri: Sims & Easton, 1972 : 233. DIAGNOSIS. Metapheretima with simple male pores; spermathecal pores about one third of thebody circumference apart in furrows (4/5/6) 6/7/8/9. Holandric. Setal numbers intermediate(cf. elongata, fig. 2). Spermathecal diverticula simple, ectal. DESCRIPTION. External characters. Length 26-80 mm, diameter 2-3 mm. 78-96 segments.Clitellum xiv-xvi. First dorsal pore 12/13. Setae, 32-54 on vii, 36-56 on xx, setal ring regular,occasionally with slight ventral gaps (aa= \-\-5ab=yz=zz). Male pores simple, c. 0-22 body circumference apart. Female pores paired. Spermathecalpores small, paired in 6/7/8/9 and usually 5/6 and 4/5, c. 0-26-0-40 body circumference apart. Genital markings (Fig. 36c), paired, presetal, median or slightly lateral to the line of the sper-mathecal pores on vii-ix, in line with the male pores on xvii, xix-xx. Internal characters. Septa 5/6/7/8 slightly thickened, 8/9 membranous or absent, 9/10-13/14slightly thickened. Intestine begins in xv. Lateral hearts in x-xii. Holandric, testes sacs paired, small, ventral in jc and xi, seminal vesicles extending to the dorsalline in xi and xii. Spermathecae (Fig. 32h) paired, usually in v-ix, those of v and vi may be absent. DISTRIBUTION. New Hebrides. REMARKS. The type series of speiseri and the specimens identified by Pickford (1929) display con-siderable variation in the development of the posterior male organs and Spermathecae. Michael-sen (1913) recognized two conditions (A and B) and Pickford (1929) a third (C) to which sheprovided the following diagnosis : ACAECATE PHERETIMOID EARTHWORMS 93 A-form without prostates and male pores but with fully developed spermathecae. B-form with prostates and male pores but with reduced spermathecae. C-form with prostates, male pores and fully developed spermathecae. Variation of this kind is often encountered among the species of the Pheretima group, especiallyin introduced populations where it has been utilized to establish the indigenous range of somespecies (Gates, 1956; Easton, 1976). It is not considered to have any taxonomic significance.Nevertheless, the single example examined of form A has more widely paired spermathecal pores(c. 0-40) than individuals of both forms B and C (c, 0-26), and more closely paired preclitellargenital markings. MATERIAL EXAMINED. Previously reported. 2C Espiritu Santo, New Hebrides; Hamburg v8071(syntypes of speiseri). 8A Summit of Tabwe Masana, Espiritu Santo, New Hebrides; BMNH1929.6.11.1-7 (speiseri: Pickford, 1929). 1C, 2A Near shore of lake, Gaua, New Hebrides; BMNH1928.3.22.11 (speiseri: Pickford, 1929). Fragments of 1C, data as above; Hamburg vl!966(speiseri: Pickford, 1929).New record. 6C Tatarii, west Santo, New Hebrides; BMNH 1934.3.6.24-26. Metapheretima elrondi sp. nov. DIAGNOSIS. Metapheretima with simple male pores ; paired spermathecal pores about one quarterof the body circumference apart in furrows 5/6/7/8/9. Holandric. Setae numerous (cf. sentanensis,Fig. 2). Spermathecal diverticula simple. DESCRIPTION. External characters. Length 50-133 mm, diameter c. 5 mm. C. 106 segments.Clitellum xiv-xvi. First dorsal pore 12/13. Setae, 88-220 on vii, 40-60 on xx, setal ring regular(aa = ab=yzzz). Male pores simple, c. 0-25 body circumference apart. Female pores paired. Spermathecal poressmall, paired in 5/6/7/8/9, c. 0-25 body circumference apart. Genital markings (Fig. 37a) paired, presetal, slightly median to the line of the spermathecalpores on ix-xi, slightly median to the line of the male pores on xvii, xx-xxiii.Internal characters. Septa 5/6/7/8 thickened, 8/9 slightly thickened, 9/10 and succeeding septadelicate. Intestine begins in xvi. Lateral hearts in x-xii. Holandric, testes sacs paired, ventral with dorsal connections over the oesophagus in x and xi;seminal vesicles small, those of xi enclosed in the testes sacs. Pseudoseminal vesicles in xiv.Spermathecae (Fig. 32i) paired in vi-ix. DISTRIBUTION. New Guinea. MATERIAL EXAMINED. 6C, 3A Soil of alluvial clay derived from gabbro, pH 5-5-6-3, highly humidi-fied, organic content 15-30%, C/N ratio 8-9. Gentle ridge covered in mixed lower montane forestwith Podocarpus, Eleocarpace, Lauracae, Cunoniaceae dominant, Bismark range, Eastern High-land district, Papua New Guinea, 5 58' S, 145 15' E, rainfall 890 cm/year, altitude 2500 m, collD R Kershaw 20 Jul 1971; BMNH 1976.5.116-124 (syntypes of elrondi). 13C, 18A Locality andcollector as above; BMNH 1976.5.125-156. 2C, 4A Locality and collector as above; Papua NewGuinea. Metapheretima sola sp. nov. DIAGNOSIS. Metapheretima with simple male pores ; closely paired spermathecal pores in furrows5/6/7/8/9. Metandric. Setae sparse (cf. kinabaluensis, Fig. 2). Spermathecal diverticula simple, ectal. DESCRIPTION. External characters. Length c. 96 mm, diameter c. 4 mm. C. 76 segments. Clitellumxiv-xvi, first dorsal pore 12/13. Setae, c. 27 on vii, c. 41 on xx, setal ring slightly crowded ventrally(2aa = 2ab=yz = zz). Male pores simple, c. 0-08 body circumference apart. Female pores paired. Spermathecal poreslarge, paired, in 5/6/7/8/9, c. 0-08 body circumference apart. Genital markings (Fig. 37b), paired, presetal, in line with the spermathecal pores on vi-ix, inline with the male pores on xvii, xix-xxi. 94 E. G. EASTON C*v .... C*^/ f / <S) <^-.\ ' M* !^1 a b c Fig. 37 Anterior ventral surface, diagnostic characters, (a) Metapheretima elrondi sp. nov.;(b) M. sola sp. nov. ; (c) M. triciae sp. nov. typical individual. Internal characters. Septa 5/6/7/8 membranous, 8/9 absent, 9/10-12/13 slightly thickened. Oeso-phagus with slight, dorsolateral pouches in xi. Intestine begins in xv. Lateral hearts in x-xii. Metandric, testes sacs large, paired, ventral in xi, seminal vesicles large, extending to the dorsalline in xii. Pseudoseminal vesicles absent. Spermathecae (Fig. 32j) paired in vi-ix. DISTRIBUTION. New Guinea. MATERIAL EXAMINED. 1C Mt Suckling, Papua New Guinea, 9 46' S, 149 00' E, coll W H EwerJun 1972; BMNH 1976.4.63 (holotype of sola). Metapheretima triciae sp. nov. DIAGNOSIS. Metapheretima with simple male pores; paired spermathecal pores one third to onesixth of the body circumference apart in furrows 5/6/7/8/9. Metandric. Setal numbers high (Fig.2). Spermathecal diverticula simple, ectal. DESCRIPTION. External characters. Length 65-114 mm, exceptionally 235 mm, diameter 3-5 mm,exceptionally 8 mm. 110-156 segments. Clitellum xiv-xvi. First dorsal pore 11/12 or 12/13. Setae,100-135 (188) on vii, 41-60 (140) on xx, setal ring usually single, occasionally double on iv-xi;regular with dorsal and ventral gaps on postclitellar segments (aa = 2ab = 2yz = zz). Male pores simple, 0-17-0-26 body circumference apart. Female pores single or paired. Sperma-thecal pores small, paired, in 5/6/7/8/9, 0-14-0-35 body circumference apart. Genital markings highly variable (Figs 37c, 38) paired, presetal on vi-x, postsetal on vi-ix,one or more pairs, presetal on xvi-xxiii, postsetal on xvii. ACAECATE PHERETIMOID EARTHWORMS 95 Fig. 38 Metapheretima triciae sp. nov. Ventral markings: geographical variations, (a) Madang(type locality); (b) Langemak Bay; (c) Mt Suckling; (d) Milne Bay; (e) Trobriand Islands.Numerals indicate numbers of clitellate individuals examined. Closed circles - markings invariablypresent; open circles - markings occasionally present. 96 E. G. EASTON Internal characters. Septa 5/6/7/8 thickened. 8/9/10 membranous or absent, 10/11-12/13 mem-branous. Oesophagus simple or with small, dorsolateral pouches in x. Intestine begins in xv.Lateral hearts in x-xii. Metandric, testes sacs large paired, often joined above the intestine, in xi, seminal vesiclesreaching the dorsolateral or dorsal line in xii. Pseudoseminal vesicles in xiii. Spermathecae(Fig. 32k) paired in v-ix. DISTRIBUTION. East and northeast New Guinea. REMARKS. The genital markings of this species are variable although usually constant in specimensfrom one locality. It has not been possible to establish any correlations between the many papillaepatterns, the various distances separating the spermathecal pores and the conditions of the testessacs ; for convenience, therefore, populations possessing these variations are not separated taxo-nomically. MATERIAL EXAMINED. 22C, 1A Waterlogged dark sandy loam with a high organic content, vege-tation of ferns, grass and coconut, close to sea, Bunu village no 2, Madang district, Papua NewGuinea, 4 52' S, 145 49' E, coll J W Copland 14 Nov 1971 ; BMNH 1976.3.130-154 (syntypes oftriciae). 12C, 8A Data as above; BMNH 1977.1.153-172. 15C, 18A Mau 1, Mt Suckling, PapuaNew Guinea, coll W H Ewers Jun 1972; BMNH 1976.4.7-29, 68-81, 140. 15C, 8A Samarai,Milne Bay, Papua New Guinea, coll J W Copland 21 Jul 1971; BMNH 1977.1.173-194. 4ASineada, Milne Bay, Papua New Guinea, coll J W Copland 22 Jul 1971 ; BMNH 1977.1.197-200.2C, Trobriand Islands, Papua New Guinea, coll J W Copland; BMNH 1977.1.195-196. 3C, 1APapua New Guinea (label completely destroyed), coll J W Copland; BMNH 1977.1.201-204. 2C,1 posterior fragment, rotting stems of wood at waterfall Langemak Bay, east Coast, Papua NewGuinea; Hamburg 01.13177 (specimens separated from type series of M. pattens (Ude, 1932)). Metapheretima tmkensis (Ohfuchi, 1940) Pheretima trukensis Ohfuchi, 1940 : 24.Metapheretima trukensis'. Sims & Easton, 1972 : 233. DIAGNOSIS. Metapheretima with simple male pores ; closely paired spermathecal pores in furrows5/6/7/8. DESCRIPTION. External characters. Length 189-193 mm, diameter 6-7-7-3 mm. 130-135 segments.Clitellum xiv-xvi. First dorsal pore 12/13. Setae 36-38 on vii, 75-80 on xx, details of setal ringnot recorded. Male pores 'minute' on conical papillae or circular porophores (Ohfuchi, 1940 was unable todetect which of the structures on xviii carried the male pores), separation not recorded. Femalepores not recorded. Spermathecal pores paired in 5/6/7/8, c. 0-10 body circumference apart. Genital markings (Fig. 39a) several paired markings, presetal on xix-xxi, postsetal on xvii,xviii. Internal characters. Septa 5/6/7 thickened, 8/9/10 absent, 10/11-14/15 thickened. Intestinal originxx. Lateral hearts not recorded. Holandric; testes sacs annular, x, xi seminal vesicles small, xi,xii. Spermathecae (Fig. 321) paired in vi-viii. Description after Ohfuchi (1940). DISTRIBUTION. Truk, east Carolines. REMARKS. This species has been assigned to the genus Metapheretima on the affinities revealedduring the numerical studies (see above), since it is uncertain whether the intersegmental genitalmarkings associated with the male pores are crescentic genital markings. M. trukensis possessesseveral morphological features atypical of the genus. There are two pairs of presetal genitalmarkings and the intestine begins in xx. RECORDS. 3 or more specimens Natsushima of Truk, east Carolines Islands (syntypes of trukensis). Metapheretima carolinensis (Michaelsen, 1910) Pheretima carolinensis Michaelsen, 19106 : 105; Ohfuchi, 1940 : 7.Pheretima (Polypheretimd) carolinensis: Michaelsen, 19346 : 15. ACAECATE PHERETIMOID EARTHWORMS 97 777"! MW. :m. abed Fig. 39 Anterior ventral surface, diagnostic characters, (a) Metapheretima trukensis; (b) M.carolinensis, arrows indicate furrows with numerous dorsal spermathecal pores; (c) M. sem-baluensis', (d) M. pollens. Metapheretima carolinensis: Sims & Easton, 1972 : 233. Pheretima garama Gates, 1958 : 8. Metapheretima garama: Sims & Easton, 1972 : 233. DIAGNOSIS. Metapheretima with simple male pores; numerous, dorsally placed spermathecalpores in furrows 5/6/7/8. DESCRIPTION. External characters. Length 47-191 mm, diameter 3-7 mm. 86-134 segments.Clitellum xiv-xvi. First dorsal 11/12 or 12/13. Setae, 33-53 on vii, 57-70 on xx, setal ring regularwith dorsal gaps on postclitellar segments (aa = ab=yz = Q-5zz). Male pores simple, c. 0-26 body circumference apart. Female pore single. Spermathecal poressmall transverse slits, numerous in paired batteries in 5/6/7/8, c. 0-90 body circumference apart. Genital markings, absent apart from those diagnostic of the genus (Fig. 39b).Internal characters. Septa 5/6/7/8 thickened, 8/9/10 absent, 10/11-14/15 thickened. Intestinebegins in xv. Lateral hearts in x-xii. Holandric, testes sacs paired, extending to the lateral line in x and to the dorsal line in xi,seminal vesicles of xi extending to the lateral line and enclosed in the testes sacs, those of xiiextending to the dorsal line. Pseudoseminal vesicles in xiv. Spermathecae (Fig. 32m) paired bat-teries of up to 8 spermathecae in vi-viii. DISTRIBUTION. Caroline Islands. 98 E. G. EASTON REMARKS. The original description of M. gamma differs from the type series of carolinemis onlyby its smaller size and lower setal numbers. These differences do not appear to be taxonomicallysignificant. MATERIAL EXAMINED. 2C Caroline Islands; Hamburg v33 10 (syntypes of carolinemis). ICTokongoIslet, Kapingamarangi, south Caroline Islands; New York 3569 (holotype of garamd). The originaldescription of garama was based on a further 6C and 9 A paratypes ; their present location isunknown. OTHER RECORDS. 8 specimens Angaul Island, Caroline Islands (carolinensis: Ohfuchi, 1940). Metapheretima sembaluensis (Ude, 1932) Pheretima (Pheretima) sembaluensis Ude, 1932 : 139.Metapheretima sembaluensis: Sims & Easton, 1972 : 233.Pheretima (Pheretima) rosai Ude, 1932 : 140.Metapheretima rosai: Sims & Easton, 1972 : 233. DIAGNOSIS. Metapheretima with simple male pores ; paired spermathecal pores about one fifth ofthe body circumference apart in furrows 7/8/9. Holandric. Spermathecal diverticula simple, ectal. DESCRIPTION. External characters. Length 100-210 mm, diameter 4-8 mm. 140-150 segments.Clitellum xiv-xvi. First dorsal pore 11/12 or 12/13. Setae, 60-120 on vii, 70-80 on xx, setal ringregular (aa = ab=yz= zz). Male pores, large, simple, c. 0-20 body circumference apart. Female pore single. Spermathecalpores large, paired in 7/8/9, c. 0-20 body circumference apart. Genital markings (Fig. 39c) paired, presetal, slightly median to the line of the spermathecalpores, on viii and ix, slightly median to the male pores, on xvii-xx, the pair of markings on xviiimay be fused to form a single median marking. Internal characters. Anterior septa present and thickened. Intestine begins in xv. Lateral hearts inx-xii and occasionally xiii. Holandric, testes sacs small, paired, ventral in x and xi, seminal vesicles extending to the dorsalline in xi and xii. Pseudoseminal vesicles large in xiii. Spermathecae (Fig. 32n) paired in viii-ix. DISTRIBUTION. Lombok. REMARKS. Ude (1932) described sembaluensis and rosai on material from Lombok with single(median) and paired genital markings respectively in the region of the male pores. More recentlycollected series exhibit a tendency for the paired genital markings to meet and coalesce to form asingle median marking, on this evidence it is proposed to synonomize the two taxa. M. sembaluensis is the only known species of Metapheretima occurring in Lombok where itrepresents the most westerly record of the genus. MATERIAL EXAMINED. New records. 4 A, 1A Surawadi, Lombok, 400 m, coll G Lincoln 10 Aug1973; BMNH 1975.7.15-18. 7C, 1A Bentak halfway between Tandjung and Mataram, Lombok400 m, coll G Lincoln 12-13 Aug 1973; BMNH 1975.7.19-27. OTHER RECORDS. Plateau enclosed by crater wall, Rinjani district, Sembalun, Lombok, 1200 m(type(s) of sembaluensis). Lake Tihoe, Ladjang, Lombok (type(s) of rosai). Metapheretima pallens (Ude, 1932 : 170) Pheretima (Metapheretima) pallens Ude, 1932 : 170.Metapheretima pallens: Sims & Easton, 1972 : 233. DIAGNOSIS. Metapheretima with simple male pores; paired spermathecal pores about one third ofthe body circumference. Metandric. Spermathecal diverticula simple. DESCRIPTION. External characters. Length 38-1 30 mm, diameter 4-5 mm. 90-102 segments.Clitellum xiv-xvi. First dorsal pore 11/12. Setae, 146-156 on vii, 25-30 on xx, setal ring regular ACAECATE PHERETIMOID EARTHWORMS 99 on preclitellar segments (aa = ab=yz = zz), slightly crowded ventrally with ventral gaps on post-clitellar segments (aa = 2ab=yz = zz). Male pores small transverse slits, c. 0-21 body circumference apart. Female pores single.Spermathecal pores large, paired in 7/8/9, c. 0-31 body circumference apart. Genital markings (Fig. 39d) paired, presetal, directly posterior to the spermathecal pores onviii and ix, more medianly placed on x and xi, in line with the male pores on xvii, xx-xxv.Internal characters. Septa 5/6/7/8 thickened, 8/9 absent, 9/10 membranous, 10/11 absent,1 1/12/13/14 membranous. Oesophagus with paired dorsal pouches in x-xi. Intestine begins in xvi.Lateral hearts in xi-xiii. Metandric, testes sacs small, paired, reaching the lateral line in xi, seminal vesicles extending tothe dorsal line in xii. Pseudoseminal vesicles small in xiv. Spermathecae (Fig. 32o) paired inviii-ix. DISTRIBUTION. New Guinea. MATERIAL EXAMINED. Previously reported. 2C, 1 1 A From rotting stems in woodland near waterfall,Langemak bay, east coast, Papua New Guinea; Hamburg v3482 (syntypes ofpallens). This serieswas contained in a jar with a museum label on which was written a manuscript name '. . . n. sp.Ude, 1926'. On examination the specimens were found to form two series. The first one agreesclosely with the description of M. pallens, and since the collecting details also agree with thoseprovided by Ude (1932) the material can be regarded as the hitherto missing type series of thespecies. The specimens forming the second series are described above under the name M. triciae.New records. IOC Very wet black soil, Woitape Station, Goilala, Papua New Guinea, 1600 m,coll J W Copland; BMNH 1977.1.50-59. 2C Side of creek, Faripe road, Woitape, Goilala, PapuaNew Guinea, 1850 m, coll J W Copland; BMNH 1977.1.47-49. 2C, 2A Guarimeipa, Papua NewGuinea, 1500m, coll J W Copland 7 Dec 1973; BMNN 1977.1.43-46. 11C, 6A Umboli, PapuaNew Guinea, 1800-2400 m, coll Griffiths 1972; BMNH 1976.10.1.18. Metapheretima neoguinensis species-group DIAGNOSIS. Metapheretima with simple male pores lacking associated glandular ridges. Sperma-thecal diverticula multilocular, ectal. SPECIES INCLUDED, deirdrae, loriae, neoguinensis, septocta, sucklingensis.DISTRIBUTION. South-east New Guinea, New Britain, ? Solomon Islands. REMARKS. The species forming the neoguinensis species-group are readily distinguished from oneanother by the distribution of their spermathecal pores ; loriae, 4/5/6/7/8/9 ; neoguinensis, 5/6/7/8/9;sucklingensis, 6/7/8/9; deirdrae, 7/8/9 and septocta, 7/8. All of the members of this species-groupare metandric but in view of the low information value of metandry in other species-groups ofMetapheretima, this character is not regarded as being diagnostic of the group. Metapheretima loriae (Rosa, 1898) Perichaeta loriae Rosa, 18986 : 61 ; ? Beddard, 1899 : 185 (? =M. pickfordi).Amynthas loriae: Beddard, 1900a : 641.Pheretima loriae: Michaelsen, 1900 : 281 ; Ude, 1905 : 481.Metapheretima loriae: Sims & Easton, 1972 : 231. DIAGNOSIS. Metapheretima with simple male pores; paired spermathecal pores about one quarterof the body circumference apart in furrows 4/5/6/7/8/9. Metandric. Spermathecal diverticulamultilocular, ectal. DESCRIPTION. External characters. Length 120-130 mm, diameter c. 6mm. C. 99 segments.Clitellum xiv-xvi. First dorsal pore 11/12 or 12/13. Setae, 51-63 on vii, 52-60 on xx, setal ringregular on preclitellar segments (aa = ab=yz = zz), slightly crowded ventrally on postclitellarsegments (aa = ab=Q-5yz = ' 100 E. G. EASTON Male pores simple, 0-14-0-20 body circumference apart. Female pores paired. Spermathecalpores small, paired in 4/5/6/7/8/9, 0-20-0-28 body circumference apart. Genital markings (Fig. 40a) paired, presetal, slightly median to the line of the spermathecalpores, on viii and ix, slightly median to the male pores on xvii, xix and xx.Internal characters. Septa 5/6-11/12 membranous, 12/13/14 thickened. Intestine begins in xv.Lateral hearts in x-xiii. Metandric, testes sacs small, paired in xi, seminal vesicles large, reaching to the dorsal line inxii. Spermathecae (Fig. 33a) paired in v-ix, diverticula multilocular. DISTRIBUTION. New Guinea, ? Solomon Islands. REMARKS. The record of loriae from the Solomon Islands (Beddard, 1899) is dubious since there isno reference to the presence of the diagnostic multilocular spermathecal diverticula; unfortunatelythis material cannot be located. It is more likely that Beddard's material was of the species M.pickfordi which is known only from the Solomon Islands, has only simple spermathecal diverticulaand is probably metandric. MATERIAL EXAMINED. Previously reported. 2C, 1A 'Hughibagu', Papua New Guinea; Geneva 37 (syntypes of loriae). This locality cannot be traced, possibly the name is a corruption of Hughes Bay, Furgusson Islands, 9 23' S, 150 42' E, which is near other places visited by the same collector. New record. 1C Mt Suckling, Papua New Guinea, coll W H Ewers 15 Jun 1972; BMNH 1976.4.3. OTHER RECORDS. 2 specimens, Guadalcanal, Solomon Islands (loriae: Beddard, 1899). a b Fig. 40 Anterior ventral surface, diagnostic characters, (a) Metapheretima loriae; (b) M. neoguinensis. ACAECATE PHERETIMOID EARTHWORMS Metapheretima neoguinensis (Michaelsen, 1892) 101 Perichaeta neoguinensis Michaelsen, 1892 : 299. Amynthas neoguinensis (part, i.e. acaecate specimens): Beddard, 1900# : 642. Pheretima neoguinensis: Michaelsen, 1900 : 288; Ude, 1905 : 481; (syn. helvold) Ude, 1932 : 173. Pheretima (Metapheretima) neoguinensis: Michaelsen, 1928a : 7. Metapheretima neoguinensis: Sims & Easton, 1972 : 205, 233. Pheretima helvola Ude, 1905 : 473 [non Michaelsen, 1934c : 520 ( = Metaphire hobaensis Gates, 1941)]. Metapheretima helvola: Sims & Easton, 1972 : 233. DIAGNOSIS. Metapheretima with simple male pores; paired spermathecal pores less than onetenth of the body circumference apart in furrows 5/6/7/8/9. Metandric. Spermathecal diverticulamultilocular, ectal. DESCRIPTION. External characters. Length 140-1 50 mm, diameter 6-9 mm. 94-124 segments.Clitellum xiv-xvi. First dorsal pore 12/13 or 13/14. Setae, 78-98 on vii, 66-86 on xx, setal ringregular with dorsal and ventral gaps on postclitellar segments (aa=l'5ab=l-5yz=zz). Male pores simple, 0-06-0-12 body circumference apart. Female pore paired or single. Sperma-thecal pores small, paired, in 5/6/7/8/9, 0-02-0-08 body circumference apart. Genital markings (Fig. 40b) paired, presetal in line with the male pores on xix-xxiii.Internal characters. Septa 5/6/7/8 thickened, 8/9 membranous, 9/10 membranous or absent,10/11-13/14 thickened. Intestine begins in xv. Lateral hearts in x-xiii. ^A .15;..) =\ a b c Fig. 41 Anterior ventral surface, diagnostic characters, (a) Metapheretima sucklingensissp. nov. ; (b) M. dierdrae sp. nov. ; (c) M. septocta. 102 E. G. EASTON Metandric, testes sacs small, paired, ventral in xi, seminal vesicles large, extending to the dorsalline in xii. Pseudoseminal vesicles vestigial in xiii or absent. Spermathecae (Fig. 33b) paired invi-ix, diverticula multilocular. DISTRIBUTION. New Guinea, New Britain. REMARKS. Rosa (1898) described spectablis as a variety of neoguinensis but Beddard (1900a)placed them together in synonymy. Michaelsen (1900) restricted the definition of neoguinensis andrecognized spectablis as a distinct species which Sims & Easton (1972) assigned to the genusAmynthas. The type series of helvola could not be located during the preparation of this report so it hasnot been possible to evaluate Ude's decision (1932) to place this species within the synonomy ofneoguinensis. MATERIAL EXAMINED. Previously reported. 1C New Guinea; Hamburg v332 (syntype of neoguinen-sis). 2C New Guinea; Berlin 2133 (syntypes of neoguinensis'). New record. 1C, 2A Port Moresby, Papua New Guinea, coll W E Ewer Apr 1967; BMNH1976.4.4-6. OTHER RECORDS. Ralum, New Britain (type(s) of helvola Ude, 1905). Metapheretima sucklingensis sp. nov. DIAGNOSIS. Metapheretima with simple male pores ; paired spermathecal pores about one quarterof the body circumference apart in furrows 6/7/8/9. Metandric. Spermathecal diverticula multi-locular, ectal. DESCRIPTION. External characters. Length c. 175 mm, diameter c. 6 mm. C. 160 segments.Clitellum xiv-xvi. First dorsal pore 12/13. Setae 51-76 on vii, 53-57 on xx, setal ring regular withdorsal and ventral gaps (aa = 2ab 2yz = zz). Male pores simple on small spherical porophores 0-23-0-28 body circumference apart. Femalepores paired. Spermathecal pores small, paired in 6/7/8/9, c. 0-16-0-33 body circumference apart. Genital markings (Fig. 4 la), paired, presetal, median to the line of the spermathecal pores onix and .x, in line with the male pores on xvii, xix-xxiv. Internal characters. Septa 5/6/7/8 thickened, 8/9 absent, 9/10-12/13 thickened. Oesophagusslightly pouched in x, xi. Intestine begins in xv. Lateral hearts in x-xii. Metandric, testes sacs small, paired, ventral in xi, seminal vesicles extending to the dorsal linein xii. Pseudoseminal vesicles vestigial in xiv. Spermathecae (Fig. 33c) paired in vii-ix, diverticulamultilocular. DISTRIBUTION. New Guinea. MATERIAL EXAMINED. 2C, 1A Mt Suckling, Papua New Guinea, 9 46' S, 149 00' E, coll W HEwer 1972; BMNH 1976.4.64-66 (syntypes of sucklingensis). 1C In large bunches of fruits ofFucus sp., close to ground, Mt Suckling, Papua New Guinea, coll G Leach 5 Jul 1972; BMNH1976.4.67. Metapheretima deirdrae sp. nov. DIAGNOSIS. Metapheretima with simple male pores ; paired spermathecal pores about one fifth ofthe body circumference apart in furrows 7/8/9. Metandric. Spermathecal diverticula multilocular,ectal. DESCRIPTION. External characters. Length 180-210 mm, diameter 5-7 mm. 250-259 segments.Clitellum xiv-xvi. First dorsal pore 12/13. Setae, c. 110 on vii, c. 88 on xx, setal ring regular(aa = ab =yz = zz). Male pores large, each surrounded by an annulus of pigmented epidermis, c. 0-14 body cir-cumference apart. Female pores paired. Spermathecal pores large, paired in 7/8/9, c. 0-19 bodycircumference apart. ACAECATE PHERETIMOID EARTHWORMS 103 Genital markings (Fig. 41b) paired, pre- and postsetal on vii-x, slightly median to the line of thespermathecal pores, presetal slightly median to the male pores on xvii-xxi.Internal characters. Septa 5/6-7/8 thickened, 8/9 membranous, 9/10-13/14 membranous. Intestinebegins in xv. Lateral hearts in x-xiii. Metandric, testes sacs small, paired extending to the lateral line in xi, seminal vesicles in xii.Spermathecae (Fig. 33d) paired in viii and ix, diverticula multilocular. DISTRIBUTION. New Guinea. REMARKS. The crescentic markings diagnostic of the genus Metapheretima are apparently absentfrom the type series of this species although the annuli of pigmented epidermis surrounding themale pores may represent a modified form of these markings. The species has many affinitieswith other members of the Metapheretima neoguinensis species group including the presence ofmultilocular spermathecal diverticula. MATERIAL EXAMINED. 2C, 3A Slope in sun with only a little vegetation, Lavavai, Papua NewGuinea 8 23' S, 147 03' E, 1600 m, coll J W Copland; BMNH 1977.1.4-8 (syntypes of deirdrae). Metapheretima septocta sp. nov. DIAGNOSIS. Metapheretima with simple male pores ; paired spermathecal pores about one fifth ofthe body circumference apart in furrow 7/8. Metandric. Spermathecal diverticula multilocular,ectal. DESCRIPTION. External characters. Length c. 103mm, diameter c. 4mm. C. 112 segments.Clitellum xiv-xvi. First dorsal pore 12/13. Setae, c. 43 on vii, c. 46 on xx, setal ring regular withventral gaps on preclitellar segments (aa = 2ab = 2yz = 2zz), with dorsal and ventral gaps on post-clitellar segments (aa = lab = 2yz = zz). Male pores small transverse slits on spherical porophores, c. 0-19 body circumference apart.Female pore single. Spermathecal pores small paired transverse slits in 7/8, c. 0-22 body circum-ference apart. Genital markings (Fig. 41c), paired, presetal on viii, lateral to the spermathecal pores and onxii median to the spermathecal pores, postsetal on vi and vii median to the spermathecal pores,presetal on xvii, xix-xxi slightly median to the male pores. Internal characters. Septa 5/6/7/8 thickened, 8/9 absent, 9/10-13/14 slightly thickened, intestinebegins in xvi. Lateral hearts in x-xiii. Metandric, testes paired, extending to the lateral line in xi, seminal vesicles large, extending tothe dorsal line in xii. Spermathecae (Fig. 33e) paired in viii, diverticula multilocular. DISTRIBUTION. New Guinea. MATERIAL EXAMINED. 8C Mt Suckling, Papua New Guinea, 9 46' S, 149 00' E, coll W H EwerJun 1972; BMNH 1976.4.55-62 (syntypes of septocta). Metapheretima durendali species-group DIAGNOSIS. Metapheretima with male pores on penes within copulatory pouches; large pairedspermathecal pores, usually in several furrows. Spermathecal diverticula simple, ectal in origin.Glandular ridges associated with the male pores absent. SPECIES INCLUDED, durendali, excalaberi.DISTRIBUTION. New Guinea. REMARKS. Although members of this group and the oinakensis species-group closely resemble oneanother, durendali and excalaberi may be distinguished externally by their more numerous,anteriorly situated spermathecal pores and internally by the ectal origin of the spermathecaldiverticula. M. durendali and excalaberi are sympatric and morphologically similar. Nevertheless, each maybe recognized on the distribution and separation of the spermathecal pores, separation of the 104 E. G. EASTON male pores, and arrangement of the genital markings (differences in size and setal numbers areinsignificant). The variations in the distinguishing characters are listed in Table 14. Table 14 Character variation in the Metapheretima durendali species-group Of the five samples examined, durendali and excalaberi were found together in four in which theproportion of individuals of the two species present varied. It is not possible to establish a cor-relation between the relative population densities of the species and any of the ecological data.Details of the ecological data and the numbers of specimens collected at each locality are given inTable 15. Table 15 Proportions of Metapheretima durendali and M. excalaberi found atvarious localities 1 Indicate type series. 1 The spermathecal pores of this individual were in furrows 5/6 (right side only), 6/7 (left side only) and 7/8 (bothright and left sides). Metapheretima excalaberi sp. nov. DIAGNOSIS. Metapheretima with male pores on penes within copulatory pouches; paired sperma-thecal pores about one third of the body circumference apart in furrows 4/5/6. Holandric. DESCRIPTION. External characters. Length c. 38mm, diameter c. 2mm, C. 115 segments.Clitellum xiv-xvi. First dorsal pore 11/12. Setae, 40-46 on vii, 30-35 on xx, setal ring regular(aa = ab=yz= zz). Male pores on short slim penes within shallow copulatory pouches, c. 0-22 body circumferenceapart. Female pore single. Spermathecal pores large, paired in 4/5/6, c. 0-30 body circumferenceapart. Genital markings (Fig. 42a), large, paired, presetal slightly median to the line of the male poreson xvii, xix; slightly median to the spermathecal pores on ix, xi-xiii. ACAECATE PHERETIMOID EARTHWORMS 105 Internal characters. Septa 5/6/7/8 thickened, 8/9 absent, 9/10-13/14 thickened. Intestine beginsin xv. Lateral hearts in x-xiii. Holandric, testes sacs paired, extending to the dorsal line in x and xi, seminal vesicles paired,extending to the dorsal line in xi and xii, those of xi enclosed in the testes sacs. Pseudoseminalvesicles absent. Spermathecae (Fig. 33f) paired in v and vi. DISTRIBUTION. New Guinea. MATERIAL EXAMINED. 8C, 5A Top 15 cm of alluvial clay derived from gabbro, pH 5-5-6-3,highly humidified, organic content 15-30%, C/N ratio 8-9, gentle ridge with mixed lower mon-tane forest, Podocarpus, Eleocarpacae, Lauracae, Cumoniaceae dominant, Bismarck range,Eastern Highland district, Papua New Guinea, 5 57' S, 145 15' E, rainfall 890 cm/year, altitude2500 m, coll D R Kershaw 14 Jul 1971; BMNH 1976.5.75-87 (syntypes of excalaberi). 29CLocality and collector as above; BMNH 1976.5.88-115. Metapheretima durendali sp. nov. DIAGNOSIS. Metapheretima with male pores on penes within copulatory pouches ; paired sperma-thecal pores about one fifth of the body circumference apart in furrows (4/5/6) 6/7 (7/8). Holandric. DESCRIPTION. External characters. Length c. 30 mm, diameter c. 2 mm. C. 100 segments. Cli-tellum xiv-xvi. First dorsal pore 11/12. Setae 31-43 on vii, 35-47 on xx, setal ring regular(aa = ab=yz zz). .SB: / jJ'jRSB *1SS I Fig. 42 Anterior ventral surface, diagnostic characters, (a) Metapheretima excalaberi sp. nov. ; (b) M. durendali sp. nov. 106 E. G. E ASTON Male pores on short, slim penes within shallow copulatory pouches, c. 0-16 body circumferenceapart. Female pore single. Spermathecal pores large, paired in 4/5/6/7/8, rarely 5/6/7/8, 6/7/8 or6/7, c. 0-22 body circumference apart. Genital markings (Fig. 42b) large paired, presetal slightly median to the line of the male poreson xvii, xix-xxii; slightly median to the spermathecal pores on xi, xii. Internal characters. Septa 5/6-7/8 slightly thickened, 8/9 absent, 9/10-13/14 thickened. Intestinebegins in xv. Lateral hearts in x-xiii. Holandric, testes sacs paired, extending to the dorsal line in x and xi, seminal vesicles paired,extending to the dorsal line in xi and xii, those of xi enclosed in the testes sacs. Spermathecae(Fig. 33g) paired, usually in v-viii, rarely in vi-viii, vii-viii or vii only. DISTRIBUTION. New Guinea. MATERIAL EXAMINED. 26C Top 30 cm of soil of alluvial clay derived from gabbro, pH 5-5-6-3,highly humidified, organic content 1 5-30 %, C/N ratio 8-9, wet gully covered with mixed lowermontane forest, Podocarpus, Eleocarpacae, Lauracae Cumoniaceae dominant, Bismarck range,Eastern Highland district, Papua New Guinea, 5 57' S, 145 15' E, rainfall 890 cm/year, altitude2500m, coll D R Kershaw 20 Jul 1971; BMNH 1976.5.30-65 (syntypes of durendali). 34C, 2AData and collector as above; BMNH 1976.5.1-29, 66-74. Metapheretima oinakensis species-group DIAGNOSIS. Metapheretima with male pores on penes, usually within copulatory pouches; largepaired, spermathecal pores in one or two furrows. Spermathecal diverticula simple, ectal in origin.Glandular ridges usually associated with the male pores. SPECIES INCLUDED, andurili, dorii, glamdringi, kilii, oinakensis, orcrista, parmata, stingi, tawarinen-sis. DISTRIBUTION. New Guinea. REMARKS. M . andurili may be readily distinguished from the other members of this species-groupby the occurrence of the spermathecal pores in furrow 5/6 and occasionally 6/7, instead of infurrow 7/8 only. Marker characters for the recognition of the species with spermathecal pores infurrow 7/8 only are given in Table 16. Table 16 Marker characters of the members of the Metapheretima oinakensis species-group with sperma-thecal pores in furrow 7/8 only Metapheretima tawarinensis (Cognetti, 1911) Pheretima tawarinensis (sic) Cognetti, 1911 : 2.Pheretima tawarinensis: Cognetti, 1912 : 543.Metapheretima tawarinensis'. Sims & Easton, 1972 : 233. ACAECATE PHERETIMOID EARTHWORMS 107 DIAGNOSIS. Metapheretima with simple male pores on short penes; large spermathecal poresabout one sixth of the body circumference apart in furrow 7/8. Holandric. Spermathecal diverti-cula simple and ental. DESCRIPTION. External characters. Length 15-130 mm, diameter 1-5-3 mm. 73-121 segments.Clitellum xiii-xvi. First dorsal pore 11/12 or 12/13. Setae, 38-82 on vii, 34-4Q on xx, setal ringregular with ventral gaps on postclitellar segments (aa = lab = 2yz = 2zz). Male pores on short, stout penes not incorporated in copulatory pouches, c. 0-16-0-18 bodycircumference apart. Female pores paired. Spermathecal pores large in 7/8, c. 0-14-0-16 bodycircumference apart. Genital markings (Fig. 43a) large, paired presetal on x or occasionally viii, in line with thespermathecal pores, paired, presetal on xix, xx and rarely more posterior segments, postsetal onxvii, in line with the male pores. The presetal region of xvii is elevated to form a ridge similar tothat found in Metapheretima kilii and M. dorii. Internal characters. Septa 5/6/7/8 slightly thickened, 8/9/10 absent, 10/11/12/13 slightly thickened.Intestine begins in xv. Lateral hearts in x-xiii. Holandric, testes sacs small, paired, ventral in x and xi, seminal vesicles extending to the dorsalline in xi and xii. Spermathecae (Fig. 33h) paired in viii. DISTRIBUTION. New Guinea. REMARKS. The descriptions of this species provided by Cognetti (1911, 1912) were based on theexamination of a single clitellate specimen 15 mm long which lacked genital markings. Because ofthe poor condition of the holotype Cognetti was unable to determine the beginning of the intestine,whether the species possessed intestinal caeca, the positions of the lateral hearts or the conditionof the anterior male reproductive system. The new specimens have been identified as this specieson the basis of the long clitellum, shape of spermathecae and the separation of the male and sper-mathecal pores. MATERIAL EXAMINED. Previously reported. 1C Tawarin, New Guinea; Amsterdam Vol. 308(holotype of tawarinensis). New records. 1C, 1A Kaironk valley, Schrader range, Papua New Guinea, 1750 m, coll R N HBuhner; BMNH 1976.2.68-69. 1C, 1A Webag, Western Highlands, Papua New Guinea, collJ W Copland; BMNH 1976.3.402-3. 12C Bismarck range, Eastern Highland district, Papua NewGuinea, 2500m, coll D R Kershaw 1971; BMNH 1976.5.184-188, 195-204. Metapheretima kilii sp. nov. DIAGNOSIS. Metapheretima with male pores on penes ; large paired spermathecal pores about onefifth of the body circumference apart in furrow 7/8. Metandric. Spermathecal diverticula simpleand ental. Male genital field as Fig. 43b. DESCRIPTION. External characters. Length 300 to over 335 mm, diameter 9-10 mm. C. 253segments. Clitellum xiv-xvi. First dorsal pore 13/14. Setae, c. 265 on vii, c. 200 on xx, setal ringregular on preclitellar segments (aa = ab=yz=zz), slightly crowded ventrally on postclitellarsegments (2aa = 2ab=yz=zz). Male pores on stout penes c. 0-20 body circumference apart. Female pores paired. Spermathecalpores paired, large transverse slits in 7/8, c. 0-20 body circumference part. Genital markings (Fig. 43b) closely paired, postsetal on xvii, presetal on xix.Internal characters. Septa 5/6/7/8 thickened, 8/9/10 absent, 10/11-13/14 membranous. Oesophaguswith paired, slight dorsolateral pouches in xi. Intestine begins in xvi. Lateral hearts in x-xiii. Metandric, testes sacs small, paired, spherical, lateromedian in position, in xi, seminal vesicleslarge, reaching the dorsal line in xii. Copulatory pouches absent. Spermathecae (Fig. 33i) pairedin viii. DISTRIBUTION. New Guinea. 108 E. G. E ASTON <8>- \SEE5i Anterior ventral surface, diagnostic characters, (a) Metapheretima tawarinensis',(b) M. A://// sp. nov. ; (c) M. <for sp. nov. Fig. 43 MATERIAL EXAMINED. 2C, 1A Moist, dense mixture of peat and soil, very rich in humus, LandResettlement Scheme (area drained 3 years prior to collection), Kendig, Mt Hagen district,Western Highlands, Papua New Guinea, 5 48' S, 144 26' E, coll J W Copland 15 Nov 1971;BMNH 1976.3.33-35 (syntypes of kiln). 31 A Dark sandy loam covered by light vegetation,120-150 m above Nupa village, Bena Bena subdistrict, c 15 miles east of Goroka, Eastern High-lands, Papua New Guinea, coll J W Copland 12 Oct 1971; BMNH 1976.3.36-67. 1A Kaironkvalley, Schrader range, Madang district, Papua New Guinea, 1750 m, coll R N H Bulmer 9 Nov1973; BMNH 1976.2.70. 3C, 6A Bismarck range, Eastern Highlands, Papua New Guinea, 2500 m,coll D R Kershaw 14-20 Jul 1971; BMNH 157-165. 18A Nupa village, Bena Bena subdistrict,c. 15 miles east of Goroka, Eastern Highlands, Papua New Guinea, coll J W Copland 13 Nov1971; BMNH 1977.1.15-32. 5A' Locality as above, coll J W Copland 31 Aug 1971; BMNH1977.1.33-37. Metapheretima dorii sp. nov. DIAGNOSIS. Metapheretima with male pores on penes; paired spermathecal pores about one thirdof the body circumference apart in furrow 7/8. Metandric. Spermathecal diverticula simple andental. Male genital field as Fig. 43c. DESCRIPTION. External characters. Length c. 145, diameter c. 6mm. C. 161 segments. Clitellumxiv-xvi. First dorsal pore 12/13. Setae, c. 174 on vii, c. 70 on xx, setal ring regular on preclitellarsegments (aa = ab=yz=zz) with dorsal and ventral gaps on postclitellar segments (aa = 2ab =2yz = zz). ACAECATE PHERETIMOID EARTHWORMS 109 Male pores on stout penes, c. 0-26 body circumference apart. Female pores paired. Spermathe-cal pores paired, large transverse slits in 7/8, c. 0-37 body circumference apart. Genital markings (Fig. 43c) paired, slightly median to the male pores, postsetal on xvii, xx-xxiv.Setal on xviii. Internal characters. Septa 5/6/7/8 thick, 8/9 absent, 9/10-13/14 membranous. Oesophagus withslight paired dorsal pouches in xi. Intestine begins in xv. Lateral hearts in x-xii. Metandric, testes sacs small, spherical paired, lateroventral in position in xi, seminal vesicleslarge, elongate in xii. Pseudoseminal vesicles in xiii, vestigial, xiv, medium sized. Copulatorypouches absent. Spermathecae (Fig. 33j) paired in vtii. DISTRIBUTION. New Guinea. MATERIAL EXAMINED. 3C, 6A Moist dark loam of moderate-high organic content, sloping plotbeing prepared for Kau Kau, boundary of Wabag, Western Highlands, Papua New Guinea,5 28' S, 143 40' E, altitude 2000-3000 m, coll J W Copland 16 Nov 1971 ; BMNH 1976.3.23.31(syntypes of dorii). 1C Data and collector as above; BMNH 1976.3.32. Metapheretima andurili sp. nov. DIAGNOSIS. Metapheretima with male pores on slim penes within copulatory pouches; largepaired spermathecal pores one quarter to two fifths of the body circumference apart in furrow5/6 and occasionally 6/7. Metandric, spermathecal diverticulum simple and ental in origin. DESCRIPTION. External characters. Length 60-72 mm, diameter 3-4 mm. 64-79 segments. Clitel-lum xiv-xvi. First dorsal pore 12/13. Setae, 43-56 on vii, 40-65 on xx, setal ring regular(aa = ab =yz = zz). Male pores on long slim penes within copulatory pouches 0-24-0-29 body circumference apart.Female pore(s) single or paired. Spermathecal pores large, paired in 5/6 and occasionally 6/7,0-26-0-42 body circumference apart. Genital markings (Fig. 44a), paired, presetal, median to the spermathecal pores on vi, medianto the male pores on xviii, crescentic markings of xviii absent. Internal characters. Septa 5/6-7/8 slightly thickened, 8/9/10 absent, 10/11-13/14 slightly thickened.Intestine begins in xv. Lateral hearts in x-xii. Metandric, testes sacs small, ventral in xi, seminal vesicles large, trilobate, reaching the dorsalline in xii. Pseudoseminal vesicles vestigial in xiii and xiv. Copulatory pouches large, sphericalinvading the coelom of xviii, penes long and slender. Spermathecae (Fig. 33k) paired in vi andoccasionally in vii. DISTRIBUTION. South-east New Guinea. REMARKS. The individual reported from Mt Suckling differs from the type series by the sperma-thecal pores being more closely paired, an additional pair of Spermathecae opening into furrow6/7, more numerous setae and the lack of genital markings. The absence of genital markings andthe number of setae may be attributed to a different state of maturity but the differences in thespermathecal system may indicate that this specimen represents a separate taxon. In the absenceof an adequate series of specimens it is not proposed to recognize these differences taxonomically.None of the four individuals examined possesses the crescentic markings diagnostic of the genusbut the form of the copulatory pouches and penes, spermathecal pores and spermathecal diver-ticula are consistent with those present in other members of the Metapheretima oinakensis species-group. MATERIAL EXAMINED. 3C Sarari, Milne Bay, Papua New Guinea, 10 36' S, 150 39' E, coll J WCopland 21 Jul 1971; BMNH 1977.1.1-3 (syntypes of andurili). 1C Mt Suckling, Papua NewGuinea, coll W H Ewer Jun 1972; BMNH 1976.4.1. Metapheretima stingi sp. nov. DIAGNOSIS. Metapheretima with male pores on penes within copulatory pouches ; paired sperma-thecal pores about one eighth of the body circumference apart in furrow 7/8. Holandric. Sperma-thecal diverticula simple and ental. Male genital field as Fig. 44b. 10 E. G. E ASTON DESCRIPTION. External characters. Length 74-94 mm, diameter c. 2 mm. 126-128 segments.Clitellum xiv-xvi. First dorsal pore 12/13. Setae, 76-84 on vii, c. 40 on xx, setal ring regular onpreclitellar segments (aa = ab=yz = zz), with dorsal and ventral gaps on postclitellar segments(aa = lab = 2yz = zz). Male pores on elongate lobate penes within shallow copulatory pouches, c. 0-14 body circum-ference apart. Female pores paired. Spermathecal pores large, paired in 7/8, c. 0-12 body circum-ference apart. Genital markings (Fig. 44b) single presetal extending beyond the line on the male pores, onxix and xx, postsetal crescentic markings of xviii absent. Internal characters. Septa 5/6/7/8 thickened, 8/9 membranous, 9/10 absent 10/11/12/13/14membranous. Intestine begins in xvi. Lateral hearts in x-xii. Holandric, testes sacs paired, large with dorsal connections between the members of a pair,enclosing the lateral hearts and in xi the seminal vesicles. Seminal vesicles in xi small, in xiilarge, extending to the dorsal line. Male pores on elongate penes within coelomic copulatorypouches. Spermathecae (Fig. 331) paired in viii. DISTRIBUTION. New Guinea. MATERIAL EXAMINED. 2C Moist medium to heavy dark loam with considerable organic content,covered by mat of Paspalum, bank of small creek running through no. 12 paddock, Sepik plainsLivestock station, Urimo, Wewak, Sepik district, Papua New Guinea, 3 49' S, 143 41' E, collJ W Copland 11 Nov 1971; BMNH 1976.3.11-12 (syntypes of stingi). 1C, 1A Data and collectoras above; BMNH 1977.1. 151-152 (syntypes of stingi). m (*)() (>.*.. ;3E.l-.-Q a b c Fig. 44 Anterior ventral surface, diagnostic characters, (a) Metapheretima andurili sp. nov. ;(b) M. stingi sp. nov. ; (c) M. oinakensis. ACAECATE PHERETIMOID EARTHWORMS Metapheretima oinakensis (Cognetti, 1914) 111 Pheretima oinakensis Cognetti, 1914 : 355. Metapheretima oinakensis: Sims & Easton, 1972 : 181, 233. DIAGNOSIS. Metapheretima with male pores on penes within copulatory pouches; paired sperma-thecal pores about one quarter of the body circumference apart in furrow 7/8. Holandric. Sperma-thecal diverticula simple and ental. Postclitellar genital field as Fig. 44c. DESCRIPTION. External characters. Length 38-107 mm, diameter 3-4 mm. 90-156 segments.Clitellum xiv-xvi. First dorsal pore 12/13. Setae 100-120 on vii, 30-60 on xx, setal ring regular onpreclitellar segments (aa = ab=yz = zz), with ventral gaps on postclitellar segments (aa = 2ab =2yz=2zz). Male pores on slim elongate penes within copulatory pouches, c. 0-25 body circumferenceapart. Female pores paired. Spermathecal pores, large, paired, in 7/8, c. 0-25 body circumferenceapart. Genital markings (Fig. 44c) paired, presetal on ix-xiii median to the line of the spermathecalpores, on xviii, xix-xxii, median to the line of the male pores. Internal characters. Septa 5/6/7/8 thickened, 8/9 absent, 9/10-12/13 membranous. Intestine beginsin xv. Lateral hearts in ix-xii. Holandric, testes sacs small paired, ventral in x, paired, extending to the dorsal line in xi.Seminal vesicles small, in ix enclosed by the testes sacs. Pseudoseminal vesicles small xiv. Sperma-thecae (Fig. 33m) paired in viii. abed Fig. 45 Anterior ventral surface, diagnostic characters, (a) Metapheretima orcrista sp. nov. ;(b) M. parmata; (c) M. glamdringi sp. nov. ; (d) M. jocchana. 112 E. G. EASTON DISTRIBUTION. New Guinea. MATERIAL EXAMINED. Previously reported. 1C Oinake, New Guinea; Leiden 1838 (holotype of oinakensis). New record. 9C, 1A Moist dark loam of moderate to high organic content, sloping plot being prepared for Kaukau, or boundary of Wabag, Western Highlands, Papua New Guinea, altitude 2000-3000 m, coll J W Copland 16 Nov 1971; BMNH 1976.3.1-10. Metapheretima orcrista sp. nov. DIAGNOSIS. Metapheretima with male pores on elongate penes within copulatory pouches ; pairedspermathecal pores about one twelfth of the body circumference apart in furrow 7/8. Holandric.Spermathecal diverticula simple and ental. Male pores surrounded by a well-developed glandularridge (Fig. 45a). DESCRIPTION. External characters. Length 72-95 mm, diameter 2-4 mm. 112-140 segments.Clitellum xiv-xvi. First dorsal pore 12/13. Setae, c. 140 on vii, c. 50 on xx, setal ring regular onpreclitellar segments (aa = ab=yz=zz), with dorsal and ventral gaps on postclitellar segments(aa = lab = 2yz = zz). Male pores on elongate penes within copulatory pouches, c. 0-12 body circumference apart.Female pore single. Spermathecal pores large, paired, in 7/8, c. 0-07 body circumference apart. Genital markings (Fig. 45a), single, median, presetal to setal on jc. Openings of the copulatorypouches are depressed and surrounded by a glandular ridge which occupies xvii-xix. This ridgealso separates the two pores. On the inner surface of this glandular wall are two pairs of faint,slightly crescentic markings, one pair at 17/18 and the other pair at 19/20, both pairs in line withthe male pores. Internal characters. Septa 5/6/7/8 thickened, 8/9 absent, 9/10 membranous, 10/11 absent,11/12/13/14 membranous or slightly thickened. Intestine begins in xvi. Lateral hearts in x-xii. Holandric, testes sacs paired, small, ventral in jc and xi. Seminal vesicles paired, in xi large,in xii smaller, both pairs extending to the dorsal line. Male pores on elongate penes within smallcoelomic copulatory pouches. Spermathecae (Fig. 33n), paired in viii. DISTRIBUTION. New Guinea. MATERIAL EXAMINED. 5C 15 cm layer of black soil over sandy soil, cultivated for gardens, halfwayup hill from creek, Department of Agriculture, Stock and Fisheries Piggery, Goroka, EasternHighlands, Papua New Guinea, 6 02' S, 145 22' E, altitude c. 3000m, coll J W Copland 13Oct 1971; BMNH 1976.3.17-21 (syntypes of orcrista). 1C Data and collector as above; BMNH1977.1.42. 2C, 2A DASF Piggery, Goroka, Eastern Highlands, Papua New Guinea, coll J WCopland 1 Sep 1971; BMNH 1977.1.38-41. 1C Moist dark loam of moderate to high organiccontent, sloping plot being prepared for Kaukau, on boundary of Wabag, Western Highlands,Papua New Guinea, coll J W Copland; BMNH 1976.3.16. 1C Dark sandy loam covered by lightvegetation, 120-150 m above Nupa village, Bena Bena subdistrict, c. 24 km east of Goroka, EasternHighlands, Papua New Guinea, coll J W Copland 12 Oct 1971 ; BMNH 1976.3.22. Metapheretima parmata (Ude, 1924) Pheretima parmata Ude, 1924 : 80. Pheretima (Pheretima) parmata'. Ude, 1932 : 134. Metapheretima parmata: Sims & Easton, 1972 : 233. DIAGNOSIS. Metapheretima with male pores on slim penes ; closely paired spermathecal pores infurrow 7/8. Holandric. Spermathecal diverticula simple ental in origin. Glandular ridges associ-ated with the male pores extending from xvii to xx (Fig. 45b). DESCRIPTION. External characters. Length c. 110mm, diameter c. 3-5 mm. C. 180 segments.Clitellum xiv-xvi. First dorsal pore 10/11. Setae, 50-65 on vii, setal ring with ventral gaps(aa=2ab). ACAECATE PHERETIMOID EARTHWORMS 1 1 3 Male pores on slim elongate penes originating directly from the body wall, closely paired.Female pores not seen. Spermathecal pores closely paired, in 7/8, in line with the male pores. Genital markings absent but the male pores are surrounded by a glandular wall extending fromxvii-xx (Fig. 45b). Internal characters. Septa 4/5-7/8 thickened, 8/9 absent, 9/10-13/14 membranous. Intestine beginsin xv. Last heart in xii. Holandric, testes sacs paired, x, xi, seminal vesicles in xi and xii. Pseudoseminal vesicles notrecorded. Spermathecae paired in viii, duct longer than ampulla, diverticulum small, pyriform,ental. Description after Ude (1924, 1932). DISTRIBUTION. New Guinea. REMARKS. This species is known only from the descriptions of Ude (1924, 1932) which are in-complete. Several details of the morphology are unknown, but it is suspected that the spermathecalpores are large as in other species with male pores on penes. RECORDS. Sepik river (Kaiserin Augusta), Papua New Guinea; Berlin 6474 (type(s) of parmata).This series is listed in the catalogue of the Berlin Museum but was lost between 1938 and 1945:Dr Hartwich, personal communication. Metapheretima glamdringi sp. nov. DIAGNOSIS. Metapheretima with male pores on slim penes within copulatory pouches; pairedspermathecal pores about one fifth of the body circumference apart in furrow 7/8. Proandric.Spermathecal diverticula simple ental in origin. Male pores surrounded by glandular ridgerestricted to xviii (Fig. 45c). DESCRIPTION. External characters. Length 130-138 mm, diameter 4-5 mm. 186-189 segments.Clitellum xiv-xvi. First dorsal pore 12/13. Setae, c. 190 on vii, c. 82 on xx, setal ring regularalthough often with displaced setae on preclitellar segments (aa = ab=yz = zz), with ventralgaps and no displaced setae on postclitellar segments (aa = 2ab = 2yz = 2zz). Male pores on elongate penes within copulatory pouches, c. 0-18 body circumference apart.Female pores paired. Spermathecal pores large, paired, transverse slits, in 7/8, c. 0-18 body cir-cumference apart. Genital markings (Fig. 45c) paired, postsetal on ix, paired, presetal on xvii, postsetal-inter-segmental on xix-xx. In addition the male pores are surrounded by a glandular wall similar tothat found in orcrista. Internal characters. Septa 5/6/7/8 thick, 8/9 membranous, 9/10 absent, 10/11-13/14 membranousor slightly thickened. Beginning of intestine not seen. Lateral hearts in x-xii. Proandric, testes sacs paired, ventral in x, seminal vesicles large, reaching the dorsal line in xi.Male pores on penes within small coelomic copulatory pouches. Spermathecae (Fig. 33o) pairedin viii. DISTRIBUTION. New Guinea. MATERIAL EXAMINED. 2C, 1A Dense clay with dense organic matter, covered by thin grass cover,side of road adjacent to coffee plantation, Amahab village, c. 16 km west of Maprik, Sepikdistrict, Papua New Guinea, 3 38' S, 142 55' E, altitude 200-500 m, coll J W Copland 12 Nov1971; BMNH 1976.3.13-15 (syntypes of glamdringi}. Metapheretima jocchana (Cognetti, 1911) Pheretima jocchana Cognetti, 1911 : 5; Cognetti, 1912 : 544; Cognetti, 1914 : 352. Pheretima (Pheretima) jocchana: Ude, 1932 : 144; (= 1 kampeni) Michaelsen, 1938 : 161. Metapheretima jocchana: Sims & Easton, 1972 : 233, 180. Pheretima kampeni Cognetti, 1914 : 356. Metapheretima kampeni: Sims & Easton, 1972 : 233. Pheretima tumulifaciens Lee, 1967 : 59. Archipheretima tumulifaciens: Sims & Easton, 1972 : 232. 1 14 E. G. EASTON DIAGNOSIS. Metapheretima with large simple male pores ; large paired spermathecal pores aboutone fifth of the body circumference apart in furrow 7/8. Holandric. Spermathecal diverticulasmall, numerous, ental in origin. DESCRIPTION. External characters. Length 200-600 mm, diameter 6-10 mm. 200-600 segments.Clitellum %xiii-%xviii. First dorsal pore 10/11, 11/12, or 12/13. Setae 150-200 on vii, 160-180 onxx, setal ring regular (aa ab=yz=zz). Male pores simple, partially invaginated in mature individuals, c. 0-30 body circumferenceapart. Female pores paired, occasionally single. Spermathecal pores large, paired, in 7/8, c. 0-20body circumference apart. Genital markings (Fig. 45d). In juveniles the markings are paired median to the male pores,postsetal on xvii, presetal on xix. With maturity the markings enlarge laterally to form a glandularridge enclosing the male pores.Internal characters. Septa 5/6-12/13 thickened. Intestine begins in xvi. Lateral hearts in x-xiii. Holandric, testes sacs small paired, ventral in x, annular in xi, seminal vesicles paired, in xienclosed in the testes sacs, and in xii. Pseudoseminal vesicles in xiv. Spermathecae (Fig. 33p)paired in viii. DISTRIBUTION. New Guinea. REMARKS. On the basis of the original description, Sims & Easton (1972) placed tumulifaciens inthe genus Archipheretima. Following an examination of the type series tumulifaciens is now trans-ferred to Metapheretima, and placed in the synonomy ofjocchana. MATERIAL EXAMINED. Previously reported. 2C Jaga, near lake Sentani, West Irian; AmsterdamVol 273 (syntypes of jocchana). 3C Njao, West Irian; Leiden 1812 (syntypes of kampeni). 3AHaripmar village, Sepik valley; Papua New Guinea; Adelaide 940-941 (holotype and paratypesof tumulifaciens). New records. 5A Moist heavy dark soil with a lot of vegetation, holding paddock of AID station,previously a Copra plantation, outskirts of Madang, Madang district, Papua New Guinea, collJ W Copland; BMNH 1976.3.68-72. 7A River flats and banks, Sepik livestock station, Urimo,Wewak, Papua New Guinea, coll J W Copland 11 Nov; 1971 BMNH 1977.1.9-14. OTHER RECORDS. New Guinea; Leiden 1851 (jocchana: Cognetti, 1914). New Guinea and Berlin-hafer, Eilape, New Guinea; Berlin 6476, 6464 (jocchana: Ude, 1932). Siwia, New Guinea; Leiden(jocchana: Michaelsen, 1938). PLEIONOGASTER Michaelsen, 1892 ?Q 108 Perichaeta (part): Beddard, 1886 : 298. Pleionogaster Michaelsen, 1892 : 247; Beddard, 1895 : 433; Michaelsen, 1896 : 198. Plionogaster: Michaelsen, 1900 : 210; Stephenson, 1930 : 840; Gates, 1943 : 105; Jamieson, 1971a : 82. TYPE SPECIES. Pleionogaster jagori Michaelsen, 1892, new designation (non horsti Beddard, 1886,invalid designation). DIAGNOSIS. Megascolecidae with an oesophageal gizzard in viii and intestinal gizzards.DESCRIPTION. As for the only species, horsti.DISTRIBUTION. Philippines, 1 Moluccas. REMARKS. Pleionogaster was erected to accommodate two species, jagori and samariensis, but atype was not designated. Later Perichaeta horsti Beddard, 1886 was transferred to the genus anddesignated as the type species. This designation is invalid (Article 69, Int. Code Zool. Nomencl.)and one of the originally included species, Pleionogaster jagori Michaelsen, 1892 (a junior synonymof horsti) is here designated as the type of Pleionogaster. The spelling of the name Pleionogaster has been the subject of confusion. Michaelsen (1892,1896) and Beddard (1895) used the correct orthography, Pleionogaster, but in 1900 Michaelsenchanged the spelling to Plionogaster, an unjustified emendation (Article 33, Int. Code Zool. ACAECATE PHERETIMOID EARTHWORMS 15 Nomencl.) which has been used by subsequent authors (Stephenson, 1930, 1933; Gates, 1943;Jamieson, 1971). Pleionogaster horstl (Beddard, 1886) Perichaeta horsti Beddard, 1886 : 300. Pleionogaster horsti: Beddard, 1895 : 434; Michaelsen, 1900 : 211. Pleionogaster jagori Michaelsen, 1892: 247; Beddard, 1895: 434; Michaelsen, 1900: 211. Pleionogaster samariensis Michaelsen, 1892 : 248; Beddard, 1895 : 434; Michaelsen, 1900 : 211. Pleionogaster ternatae Michaelsen, 1896 : 198; Michaelsen, 1900 : 211. Pleionogaster sivickisi Stephenson, 1933 : 923. Pleionogaster sp. Gates, 1943 : 105. DIAGNOSIS. As for the genus. DESCRIPTION. External characters. Length 50-170 mm, diameter 3-5 mm. 190-270 segments.Body cylindrical, creeping sole absent. Clitellum annular, xiv-xvii. First dorsal pore 11/12 or12/13. Setae perichaetine, 150-200 on vii, 70-84 on xx, setal ring regular without dorsal or ventralgaps (aa = ab=yz=zz). Male pores simple, large, coincident with the prostate pores, c. 0-24 body circumference apart.Female pore single or closely paired, median on xiv. Spermathecal pores large, paired, interseg-mental in furrows 7/8/9, c. 0-23 body circumference apart. Genital markings (Fig. 46a) paired, in line with the male pores and single median, presetal onxvi, xvii, xix, xx, paired, intersegmental, in line with the male pores at 17/18, 18/19. 1mm Fig. 46 Pleionogasier horsti. (a) Anterior ventral surface, diagnostic characters ; (b) spermatheca. 116 E. G. EASTON Internal characters. Septa 4/5-8/9 thickened. Poorly developed oesophageal gizzard in viii.Oesophagus lacking calciferous glands and dorsal pouches. Intestine begins in xix with 3 or 4gizzards, each c. | segment in length, in xxvi, xxvii, xviii and occasionally xxix. Lateral hearts inx-xiii. Holandric, testes sacs single, annular in x and xi, seminal vesicles small in xi and xii, enclosedin the testes sacs. One pair of racemose prostates discharging with the male ducts. Ovaries free,paired in xiii. Oviducts lead to single or closely paired median equatorial pore(s) on xiv. Sper-mathecae (Fig. 46b) paired in viii and ix. DISTRIBUTION. Philippine Islands and possibly the Moluccas. REMARKS. The taxa assigned to this species vary in the degree of development of the oesophagealgizzard, the number of intestinal gizzards and the number of genital markings. The variation ineach of these characters is small and insufficient to justify the recognition of more than a singlespecies. The reported occurrence of this species in the Moluccas is based on the type ofternatae (Michael-sen, 1896). In the original description the type locality was cited as Ternate' but later this localitywas qualified without explanation as 'Moluken (Ternate)' by Michaelsen (1900 : 211). Since thisspecies has otherwise been reported only from the Philippines, it is uncertain whether this recordshould be attributed instead to Ternate, Luzon, Philippines and not to Ternate Island, Halmahera. MATERIAL EXAMINED. 4 micro slides (longitudinal sections), Manila, Luzon, Philippines ; BMNH1974.1.86-89 (syntype of horsti). 2C Daraga, Luzon, Philippines; Hamburg v359 (syntypes ofjagori). 1C 'Ternate' (Halmahera or Philippines ?); Hamburg v3838 (syntype of ternatae). 1C,3A Manila, Luzon, Philippines; BMNH 1930.12.26.5-7 (syntypes if sivickisi). OTHER RECORDS. 1 specimen, Samir Island, Philippines (holotype of samariensis). More than 3AManila, Luzon, Philippines (Pleionogaster sp. Gates, 1943). Species Incertae Sedis Three species of the Pheretima group of genera are known only from individuals with damagedintestines and it is uncertain whether they possess intestinal caeca. They were listed as speciesincertae sedis by Sims & Easton (1972). Descriptions are provided below and the keys of theacaecate genera to which they are potential candidates for inclusion have provision for theirrecognition. 'Pheretima' cupreae Chen, 1946 Pheretima cupreae Chen, 1946 : 117. Pheretima cupreae incertae sedis: Sims & Easton, 1972 : 224. DESCRIPTION. External characters. Length c. 120 mm, diameter c. 6-5 mm. C. 95 segments.Clitellum xiv-xvi. First dorsal pore 11/12. Setae, c. 46 on in, c. 52 on vii, c. 53 on ix, c. 50 on xxv,setal ring with ventral and dorsal gaps (aa= \-2ab, \-5-2yz =zz). Male pores on small porophores, c. 0-33 body circumference apart. Female pore(s) not recorded.Spermathecal pores small, paired, presetal on vii and viii, c. 0-43 body circumference apart. b c Fig. 47 Spermathecae. (a) 'Pheretima' cupreae; (b) 'Pheretimd* flabellifera; (c) 'Ph'retimd 1 touranensis. All scales 0-5 mm. ACAECATE PHERETIMOID EARTHWORMS 117 Genital markings (Fig. 48a) paired, pre- and postsetal, slightly median to the spermathecalpores on vii and viii, single, postsetal, median on vii and viii, paired, clusters of 3 or 4 papillaeslightly median to the male pores on xviii and a pair of incomplete glandular walls enclose themale pores anteriorly, laterally and posteriorly. Internal characters. Septa 5/6-7/8 thickened, 8/9/10 absent, 10/1 1-12/13 thickened. Intestine beginsin xv. Lateral hearts not recorded. Holandric, testes sacs paired in x and xi, seminal vesicles paired in xi and xii. Spermathecae(Fig. 47a) in vii and viii. Description after Chen (1946). DISTRIBUTION. Szechwan, China. REMARKS. The majority of Chinese members of the Pheretima group belong to the caecate generaAmynthas and Metaphire so it is probable that P. cupreae possesses intestinal caeca and belongsto the former, Amynthas, where it would be accommodated in the pomellus species-group. How-ever, Pheretima cupreae may be a candidate to two of the acaecate genera, Polypheretima andMetapheretima. The former, Polypheretima, has an indigenous range that comes close to China,but the presence of glandular walls associated with the male pores are reminiscent of the crescenticmarkings diagnostic of Metapheretima. RECORDS. 1C (damaged) Mt King-Fu, Szechwan, China (holotype of cupreae). 9. a b c Fig. 48 Anterior ventral surface, diagnostic characters, (a) 'Pheretima' cupreae;(b) 'Pheretima' flabellifera ; (c) 'Pheretima'' touranensis. 118 E. G. EASTON 'Pheretima' flabellifera Cognetti, 1911 Pheretima flabellifera Cognetti, 1911 : 2; Cognetti, 1912 : 548.Pheretima flabellifera incertae sedis: Sims & Easton, 1972 : 224. DESCRIPTION. External characters. Length c. 26 mm, diameter c. 2-5 mm, C. 73 segments. Clitel-lum xiv-xvi. First dorsal pore not recognized. Setae, c. 50 on vii and xx, setal ring with ventral(? and possibly dorsal) gaps (aa \-5ab = \-5yz). Male pores on circular porophores c. 0-35 body circumference apart. Female pore single.Spermathecal pores small, paired, intersegmental in 5/6/7/8, c. 0-50 body circumference apart. Genital markings (Fig. 48b) single, median on viii and ix, paired, presetal, median to the malepores on xviii, paired, presetal, in line with the male pores on xix, single median, presetal onxix and xx. Internal characters. Anterior septa present and delicate. Intestine begins in xv, intestinal caeca ?Lateral hearts in x-xii. Holandric, testes sacs paired, small, ventral in x and xi, seminal vesicles extending to the dorsalline in xi and xii. Spermathecae (Fig. 47b) paired in vi-viii. DISTRIBUTION. New Guinea. REMARKS. Until data about the intestinal caeca become available for this species, it may beconsidered to be candidate for three genera of the Pheretima group of genera, Amynthas, Pithemeraand Polypheretima. With intestinal caeca it would be eligible to be included in Amynthas, andbelong to the hawayanus species-group (unknown in the Papuan area) or Pithemera. If it shouldlack caeca, then it would become a member of Polypheretima where its affinities would then bewith the bifaria species-group which is also indigenous in New Guinea. MATERIAL EXAMINED. 1C Meniheon Geb. West Irian; Amsterdam Vol 254 (holotype of flabelli-fera). 'Pheretima' touranensis Michaelsen, 1934 Pheretima (Pheretima) touranensis Michaelsen, 1934c : 499.Pheretima touranensis incertae sedis: Sims & Easton, 1972 : 225. DESCRIPTION. External characters. Length 1 10 mm, diameter 3-5-4 mm. C. 90 segments. Clitellumxiv-xvi. First dorsal pore not recorded. Setae, c. 44 on v, c. 52 on ix, c. 56 on xiii, setal ring regularwithout dorsal and ventral gaps (aa = ab=yz=zz). Male pores on large, wart-like papillae which occupy the whole length of the segment, c. 0-40body circumference apart. Female pore(s) not recorded. Spermathecal pores paired, intersegmentalin 7/8/9, c. 0-28 body circumference apart. Genital markings (Fig. 48c) paired, postsetal, in line with male pores, on xvii.Internal characters. Septa 6/7/8 slightly thickened, 8/9/10 absent, 10/11-13/14 moderately thick-ened. Beginning of intestine not recorded, intestinal caeca ? Lateral hearts not recorded. Holandric, testes sacs small, paired in x and xi, seminal vesicles large, broad, sack shaped in xiand xii. Spermathecae (Fig. 47c) paired in viii and ix. Description and Fig. 47c after Michaelsen (1934); Fig. 48c is an interpretation of the genitalfield based on Michaelsen's written description. DISTRIBUTION. Vietnam. REMARKS. Until details of the intestinal caeca become available for this species it is consideredas a candidate for inclusion in three genera of the Pheretima group, Amynthas, Pithemera andPolypheretima. If it should prove to belong to Polypheretima then it would be included within thebifaria species-group. RECORDS. 1C (badly macerated) Tourane, Vietnam (holotype of touranensis). ACAECATE PHERETIMOID EARTHWORMS 1 1 9 Species transferred to caecate genera of the Pheretima group Two of the species provisionally assigned to Metapheretima, one included in Planapheretima andfour listed as incertae sedis by Sims & Easton (1972), are now transferred to Amynthas on thebasis of the data discussed below. Perichaeta subquadrangula Grube, 1877. The original description of this species is incompleteand causes doubt whether the taxon should be included within the Pheretima group of genera.Examination of the type specimens (Berlin 706) reveal that it belongs to the Amynthas diffringensspecies-group and that it is probably synonomous with A. diffringens (Baird, 1869). Perichaeta pusilla Ude, 1893 (non Pheretima pusilla Ohfuchi, 1956) and Pheretima enchytrae-oides Michaelsen, 1916. The original descriptions lack information regarding the presence orabsence of intestinal caeca. Gates (1961 : 298) is of the opinion that they are both synonomouswith Amynthas minimus (Horst, 1893). The name A. minimus has priority; although an exact dateof publication cannot be established for Horst's paper a copy was received by the library of theBritish Museum (Natural History) on 2 August 1893 while Ude's paper was not published until12 December 1893. Pheretima monopera Cognetti, 1911. Damage to the intestine in the region of the intestinal caecaof the unique holotype prevented Cognetti from, recognizing these structures. Among recentadditions to the collections of the British Museum (Natural History) are several individuals ofmonopera. They all possess caeca so the species monopera is now transferred to Amynthas. Pheretima liangi Michaelsen, 1922 was assigned to Metapheretima by Sims & Easton (1972)since the original description recorded the absence of intestinal caeca. Re-examination of theunique holotype - Leiden 1813 (2 fragments of body wall); Hamburg v9299 (3 spermathecae,pharynx, gizzard and anterior portion of intestine) - revealed that caeca are present but it wasnot possible to establish in which segment the caeca originate. It is proposed to transfer the taxonto the genus Amynthas and include it in the A. diffringens species-group-it could possibly beassigned to the Pithemera pacifica group; however, it differs from the members of this group bybeing holandric. Pheretima petahana Michaelsen, 1934 was tentatively included in Metapheretima since Michael-sen noted that it probably lacked intestinal caeca. No further data can be obtained from a re-examination of the unique holotype (Amsterdam Vol. 293) since all internal structures have beenremoved. However, a short series of specimens (Stockholm 462) contain three clitellate individualsassignable to this species on external characters. Since these specimens have intestinal caecaoriginating in xxvii, the species is now transferred to Amynthas where it is included in the A.aeruginosus species-group. Pheretima hirudinaria Gates, 1958 was assigned to Planapheretima by Sims & Easton (1972)since the original description recorded crowded ventral setae and a depressed body. Examinationof the unique holotype - New York 7283 - revealed that the body was only slightly depressed,possibly a result of the fixation technique employed, and the setae were not crowded ventrally.In the absence of the generic characters of Planapheretima the species has been transferred toAmynthas where it is accommodated in the A. diffringens species-group. Gates (1958) was onlyable to detect a single lateral caecum on the left side of the holotype. Re-examination of the holo-type revealed that a caecum was present on the right-hand side of the intestine although it wasnot as well developed as that on the left-hand side. Several species were omitted from the numerical studies of Sims & Easton (1972) or have beendescribed since in the genus Pheretima. They are assigned to the following genera: Amynthas A. areniphilus (Chen & Hsu, 1975: 91) (cf. A. rubellus). A. geojeisulae (Song & Paik, 1970a : 11) (A. morrisi species-group). A. gucheonensis (Song & Paik, 19706 : 105) (A. tokioensis species-group). A. heterogens (Chen & Hsii, 1975: 96) (A. sieboldi species-group). A.jiriensis (Song & Paik, 1971 : 193) (A. tokioensis species-group). A. loti (Chen & Hsii, 1975: 93) (A. sieboldi species-group). A. mediocus (Chen & Hsii, 1975: 92) (A. diffringens species-group). A. nanulus (Chen & Yang, 1975: 89) (A. morrisi species-group). 120 E. G. EASTON A. seungpanensis (Song & Paik, 19700 : 11) (A. canaliculatus species-group). A. tschiliensis kokoanus (Chen & Fang, 1975: 94) (A. sieboldi species-group). Metaphire M. cruroides (Chen & Hsu, 1975: 93) (M. houletti species-group). M. yapensis (Ohfuchi, 1941 : 283) (M. houletti species-group). Pithemera P. aimerikiensis (Ohfuchi, 1941 : 302) (P. bicinta species-group). P. eldoni (Gates, 1975 : 6). P. mira (Gates, 19726 : 121) (P. sedgwicki species-group). P. palaoensis (Ohfuchi, 1941 : 287). Acknowledgements For donating material to the British Museum (Natural History) I must express my grateful thanksto: Dr R. N. H. Bulmer, Department of Anthropology and Sociology, University of Papua NewGuinea (present address: University of Auckland); Dr J. W. Copland, Veterinary Laboratory,Department of Agriculture, Stock and Fisheries, Boroko, Papua New Guinea (present address :Department of Agriculture, Benalla, Victoria); Dr W. H. Ewers, Biology Department, Universityof Papua New Guinea (present address : Warrnambool Institute of Advanced Education, Victoria) ;Dr M. Griffiths, Australian National University, Canberra; Dr D. R. Kershaw, Department ofZoology and Comparative Physiology, Queen Mary College, University of London; Mr N. T.Talbot, Veterinary Laboratory, Department of Agriculture, Stock and Fisheries, Boroko, PapuaNew Guinea and Mrs M. T. C. Wright, Malayan Tobacco Company, Kelantan, Malaysia. Forthe loan of material I must record my gratitude to: Dr D. M. Devany, Bernice P. Bishop Museum,Honolulu; Professor Dr M. Dzwillo, Zoologisches Institut und Zoologisches Museum, Univer-sitat Hamburg; Dr G. Hartwich, Museum fur Naturkunde an der Humboldt-Universitat zuBerlin; Dr S. Kadarsan, Museum Zoologicum Bogoriense, Bogor; Dr E. Kirsteuer, The AmericanMuseum of Natural History, New York; Dr J. van der Land, Rijsmuseum van NatuurlijkeHistoric, Leiden; Dr H. Laws, South Australian Museum, Adelaide; Dr R. Olerod, Natur-historiska Riksmuseet, Stockholm; Dr M. Sarica, Museo ed Institute di Zoologica Systematica,Universita di Torino; Dr S. van der Spoel, Zoologisch Museum, Universitat van Amsterdam;Dr V. Stemberger, Naturhistorisches Museum Wein, Vienna and Dr E. Tortonese, Museo Civicodi Storia Naturale 'Giacomo Doria', Genoa. For information about their collections I am grateful to : Dr G. L. Alcasid, Pambansung Museo,Manila; Dr R. Alvardo, Museo Nacional de Ciencias Naturales, Madrid; Dr P. Hitchings,The Australian Museum, Sydney; Dr M. Imajima, The National Science Museum, Tokyo andDr J. B. Kirkegaard, Universitetets Zoologiske Museum, Copenhagen. I would like to thankDr B. G. M. Jamieson, University of Queensland, for examining the type series of Metapheretimabulmeri in the Australian Museum. I am especially grateful to Mr R. W. Sims for his advice andencouragement during the preparation of this report and for reading the manuscript. Finally, Iwould like to thank Miss K. M. Shaw for her advice and making available her computer pro-grams and Mr D. W. Cooper for preparing the microslides for the morphological studies. References Aiyer, K. S. P. 1929. 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Capita Zool. 1 (3) : 1-67. 1924. Oligochaten von Hollandisch-Neuguinea. Nova Guinea 14 : 18-27. 1927. Die Oligochatenfauna Brasiliens. Abh. senckenb. naturforsch. Ges. 40 : 369-374. 1928a. Die Oligochaten Borneos. Ark. Zool. 20 (3) : 1-60. 19286. 1. Ordnung der Clitellata : Oligochaeta : Regenwiirmer und Verwandte. Handb. Zool., Berl.2(8): 1-118. 1929. Pheretima (Archipheretima) ophiodes n. sp., ein eigentiimlich bunter Regenwurm von denPhilippinen. Mitt. zool. Stlnst. Hamb. 44 : 85-90. 19300. Ein schlangenahnlicher Regenwurm aus Bergwaldern der Insel Luzon. Philipp. J. Sci.41 : 273-280. 19306. Die Oligochaten, Resultats scientifiques du voyage aux Indes-Orientales NSerlandaises. Mem. Mus. r. Hist. nat. Belg. 2 (5) : 1-25. 1932. Neue Oligochaten von Bali und Borneo. Bull. Mus. r. Hist. Belg. 8 (32) : 1-11. 1934a. Oligochaten von Niederlandisch-Indien. Archs neerl. zool. 1 : 100-117. 19346. Oligochaeta from Sarawak. Q. Jl microsc. Sci. 77: 1-47. 1934c. Oligochaten von Franzosisch-Indochina. Archs Zool. exp. gen. 76 : 493-546. 1938. Einige interessante Pheretimen von Hollandisch-Neuguinea. Zool. Anz. 121 : 161-181. Moreia, C. 1903. Vermes oligochaetos do Brazil. Archos Mus. nac. Rio de J. 12 : 129-136. Ohfuchi, S. 1937. On the species possessing four pairs of spermathecae in the genus Pheretima, together with the variability of some external and internal characters. Res. Bull. Saito Ho-on Kai Mus. 12 : 31- 136.1940. On the Oligochaeta from the East and West Carolines, South Sea Islands, I. Palao trop. biol. Stn Stud. 2 : 7-28.1941. On the Oligochaeta from the East and West Carolines, South Sea Islands, II. Palao trop. biol. Stn Stud. 2 (2) : 279-306.1951. On the terrestrial Oligochaeta from Sansei with descriptions of three new species. Misc. Rep. Res. Inst. nat. Resour. Tokyo 19-21 : 55-63. 1956. On a collection of the terrestrial Oligochaeta obtained from the various localities in the Riu- Kiu Islands, together with the consideration of their geographical distribution (Part I). J. Agric. Sci. Tokyo 3 : 131-176.Oishi, M. 1930. On the reproductive process of the earthworm, Pheretima communissima (Goto et Hatai). Part I. Sci. Rep. Tohoku Univ. 5 : 509-524.Omodeo, P. 1958. La reserve naturelle integrate du Mont Nimba, I. Oligochaetes. Mem. Inst. fr. Afr. noire 53 : 9-109.Perrier, E. 1872. Recherches pour servir a 1'histoire des Lombriciens terrestres. Nouv. Archs Mus. Hist. nat. Paris 8 : 5-198.1875. Sur les vers de terre des iles Philippines et de la Cochinchine. C. r. hebd. Seam. Acad. Sci. Paris (D) 81 : 1043-1046.Pickford, G. E. 1929. On an interesting earthworm from the New Hebrides. Ann. Mag. nat. Hist. (ser. 10) 3 : 493-498. 124 E. G. EASTON Rao, A. S. 1974. IX. The vegetation and phytogeography of Assam - Burma. Monographiae biol. 23 : 204- 246.Raven, P. H. & Axelrod, D. 1. 1972. Plate tectonics and Australasian Palaeobiography. Science 176 : 1379- 1386.Reynolds, J. W. & Cook, D. G. 1976. Nomenclature Oligochaetologica. A catalogue of names, descriptions and type specimens of the Oligochaeta, pp. i-x, 1-216. New Brunswick: University of New Brunswick.Rosa, D. 1890. Viaggio di Leonardo Fea in Birmanica e regioni vicini, XXVI. Perichaetidi. Annali Mus. civ. Stor. not. Giacomo Doria 10 : 107-122.1891. Die exotoschen Terricolen des k.k. naturhistorischen Hofmuseums. Annln naturh. Mus. Wien 6 : 379-406. 1894. Perichaetini nuovi o meno noti. Atti Acad. Sci. Torino 29 : 1-18. 1898a. On some new earthworms in the British Museum. Ann. Mag. not. Hist. (ser. 7) 2 : 276-290. 18986. Viaggio di Lamberto Loria nella Papuasia orientale, XXI. Terricoli. Annali Mus. civ. Stor. nat. Giacomo Doria 19 : 57-65.Sims, R. W. & Easton, E. G. 1972. A numerical revision of the earthworm genus Pheretima auct. (Mega- scolecidae : Oligochaeta) with the recognition of new genera and an appendix on the earthworms collected by the Royal Society North Borneo Expedition. Biol. J. Linn. Soc. 4 (3) : 169-268.Sivickis, P. B. 1930. Distribution of setae in the earthworm Pheretima benguetensis Beddard. Biol. Bull. mar. biol. Lab. Woods Hole 58 : 274-280. Song, M. J. & Paik, K. Y. 1970a. Earthworms from Chejoo-do Island, Korea. Korean J. Zool. 13 : 9-14.19706. On a small collection of earthworms from Geo-je Isl., Korea. Korean J. Zool. 13 : 101- 111. 1971. Earthworms of Mt. Jiri, Korea. Korean J. Zool. 14 : 192-198. Spencer, W. B. 1888. The anatomy of Megascolides australis (the giant earthworm of Gippsland). Trans. R. Soc. Viet. 1 : 1-60.Stephenson, J. 1923. Oligochaeta Fauna Br. India 1923 : 1-518. 1930. The Oligochaeta, pp. 1-978. Oxford: Clarendon Press. 1931 . Oligochaeta from Burma, Kenya and other parts of the world. Proc. zool. Soc. Lond. 1931 : 33- 92.1932. A reexamination of certain Oligochaeta from the Malay Peninsula (Skeat Expedition 1899- 1900). Ann. Mag. nat. Hist. (ser. 10) 9 : 201-240.1933, Oligochaeta from Australia, North Carolina, and other parts of the world. Proc. zool. Soc. Lond. 1932 : 899-941. Ude, H. 1893. Beitrage zur Kenntnis auslandischer Regenwiirmer. Z. wiss. Zool. 57 : 57-75.1905. Terricole Oligochaten von den Inseln der Sudsee und von verschiedenen andern Gebieten der Erde. Z. wiss. Zool. 83 : 405-501. 1924. Neue Pheretima-Arten von Neu-Guinea. Zool. Anz. 61 : 80-85. 1925. Regenwiirmer von Borneo. Zool. Anz. 63 : 103-109. 1932. Beitrage zur Kenntnis der Gattung Pheretima und ihrer geograpischen Verbreitung. Arch. Naturgesch. 1 : 114-190.Vaillant, M. L. 1889. Lombriciniens, Hirudiniens, Bdellomophes, Teretulariens et Planariens. In Histoire naturelle des Anneles et d'eau douce 3 : 1-766. Paris.Vati, V. 1945. The enteronephric system in Megascolex trivandranus Steph., M. auriculata Aiyer, and M. travancorensis (var. ghatensis Mich., var proboscidea Aiyer, and var typicus Mich.), with remarks on vestigial nephridia. Proc. natn. Inst. Sci. India 11 : 245-255.Wadia, D. N. 1953. The geology of India (3rd edition). London: Macmillan.1960. The post-glacial desiccation of central Asia; evolution of the arid zone of Asia. Natn. Inst. Sci. India, Monogr. 10 : 1-25. Index to specific and subspecific names New names are printed in bold type, other valid names are printed in roman type and names listed insynonymy are printed in italic type. New combinations are indicated by an asterisk (*). acystis, Perichaeta 53aimerikiensis, Pithemera* 120ambulatrix, Planapheretima 71andurili, Metapheretima 109annamensis, Polypheretima* 56annectens, Amynthas s teller i 55 annulata Polypheretima* 35 arboricola (Rosa, 1890), Planapheretima* 76 arboricola (Gates, 1936), Pheretima 76 ardita, Pheretima 88 arensi, Metapheretima 83 areniphilus, Amynthas* 119 ACAECATE PHERETIMOID EARTHWORMS 125 aringeana, Polypheretima* 55aruensis, Pheretima polytheca 42, 49 badia, Polypheretima* 59, 60bambophila, Planapheretima 78barami, Perichaeta 54baritoensis, Pheretima 54beccarii, Pheretima 27beranensis beranensis, Pheretima 54beranensis tinjarana, Pheretima 54bifaria, Polypheretima* 41bifaria wirzi, Pheretima 41biserialis, Perichaeta 53bonensis, Amynthas stelleri 54brevis, Polypheretima* 41bulmeri, Metapheretima 84 carolinensis, Metapheretima 96celebensis, Planapheretima 70continens, Planapheretima* 75coplandi, Polypheretima 62cruroides. Metaphire* 120cupreae (species incertae sedis) 116 deirdrae, Metapheretima 102dorii, Metapheretima 108durendali, Metapheretima 105 elberti, Polypheretima* 60eldoni, Pithemera* 120elongata, Polypheretima* 53elrondi, Metapheretima 93enchytraeoides, Pheretima 119everetti, Polypheretima* 54excalaberi, Metapheretima 104 fakfakensis, Polypheretima* 36fakfakensis tetratheca, Pheretima 35fida, Polypheretima* 37flabellifera (species incertae sedis) 118frondicola, Pheretima 72 garama, Pheretima 97gatesi, Polypheretima 44geojeisulae, Amynthas* 119grata, Polypheretima* 46glamdringi, Metapheretima 113gucheonensis, Amynthas* 119 hasselti, Planapheretima 71helvola, Pheretima 101heterogens, Amynthas* 119hirudinarius, Amynthas* 119horsti, Pleionogaster 115huonensis, Polypheretima 63 iizukai, Polypheretima* 43invisa, Pheretima 35iris, Archipheretima 26 jagori, Pleionogaster 115jiriensis, Amynthas* 119jocchana, Metapheretima 113 kampeni, Pheretima 113kellneri, Polypheretima* 57kershawae, Polypheretima 62kilii, Metapheretima 107kinabaluensis, Polypheretima* 54klabatensis, Amynthas stelleri 54kochii, Pheretima 35kokoanus, Amynthas tschiliensis* 120koroensis, Pheretima stelleri 54koyana, Polypheretima* 50 lacertina, Planapheretima 77lesonea, Polypheretima 51liangi, Amynthas* 119lindiae, Metapheretima 89loriae, Metapheretima 92, 99loti, Amynthas* 119 maculata, Planapheretima 73mahakkami, Pheretima stelleri 54margaritacea, Archipheretima 25mazarredi, Archipheretima 22mediocus, Amynthas* 119mertoni, Polypheretima* 40minutus, Amynthas 49mira, Pithemera* 120moelleri, Polypheretima* 38monoperus, Amynthas* 109monticola, Polypheretima* 42moultoni, Planapheretima 68myriochaeta, Pheretima 88 nanulus, Amynthas* 119neoguinensis, Metapheretima 101nieuwenhuisi, Planapheretima 74 oinakensis, Metapheretima 111ophiodes, Archipheretima 27orcrista, Metapheretima 112 palaoensis, Pithemera* 120pallens, Metapheretima 98pallescens, Planapheretima 68panarana, Polypheretima* 44, 45papillata, Perichaeta 54parmata, Metapheretima 112patae, Polypheretima 61pauli, Perichaeta 45penrisseni, Pheretima 24pentacystis, Polypheretima* 48petahanus, Amynthas* 119phacellotheca, Polypheretima* 55pickfordi, Metapheretima 91picta, Archipheretima 26polytheca, Polypheretima* 49 126 polytheca aruensis, Pheretima 42, 49pusilla, Perichaeta 119 queribunda, Metapheretima 90quinqueremis, Metapheretima 85 renschi, Polypheretima* 56rosai, Pheretima 98rufomaculata, Planapheretima 71 samariensis, Pleionogaster 115sarawacensis, Perichaeta 54scandens, Pheretima 73schaedleri, Pheretima 36sembaluensis, Metapheretima 98sempolensis, Polypheretima 39sentanensis, Metapheretima* 88sepikensis, Polypheretima* 40septocta, Metapheretima 103sera, Planapheretima 73seriatus, Amynthas stelleri 54seungpanensis, Amynthas* 120sibogae, Polypheretima* 58simsi, Metapheretima 87sivickisi, Pleionogaster 115sola, Metapheretima 93speiseri, Metapheretima* 92stelleri, Polypheretima* 55stelleri annectens, Amynthas 55stelleri bonensis, Amynthas 54 E. G. EASTON stelleri klabatensis, Amynthas 54stelleri koroensis, Pheretima 54stelleri mahakkami, Pheretima 54stelleri seriatus, Amynthas 54stingi, Metapheretima 109subquadrangulus, Amynthas* 119subulata, Planapheretima* 69sucklingensis, Metapheretima 102swelaensis, Polypheretima* 60 tamiensis, Pheretima 88taprobanae, Polypheretima* 45tawarinensis, Metapheretima 106tenebrica, Planapheretima 78ternatae, Pleionogaster 115tetratheca, Pheretima fakfakensis 35tinjarana, Pheretima beranensis 54touranensis (species incertae sedis) 118triciae, Metapheretima 94trukensis, Metapheretima 96tschiliensis kokoanus, Amynthas* 120tumulifaciens, Pheretima 113 voeltzkowi, Polypheretima* 47H/Vz/, Pheretima bifaria 41yapensis, Metaphire* 120zonata, Archipheretima 23 Manuscript accepted for publication 28 November, 1977 British Museum (Natural History)Monographs & Handbooks The Museum publishes some 10-12 new titles each year on subjectsincluding zoology, botany, palaeontology and mineralogy.Besides being important reference works, many, particularly amongthe handbooks, are useful for courses and students' backgroundreading. Lists are available free on request to : Publications Sales British Museum (Natural History) Cromwell Road London SW7 5BD Standing orders placed by educational institutions earn a discountof 10% off our published price. Titles to be published in Volume 35 A revision of the 'acaecate' earthworms of the Pheretima group(Megascolecidae: Oligochaeta) : Archipheretima, Metapheretima,Planapheretima, Pleionogaster and Polypheretima. By E. G. Easton. Miscellanea The planktonic copepods of the northeastern Atlantic Ocean:Harpacticoida, Siphonostomatoida and Mormonilloida. By G. A.BoxshalL Towards a phyletic classification of the 'genus' Haplochromis (Pisces,Cichlidae) and related taxa. Part I. By Peter Humphry Greenwood. A revision of the British species of the genus Phthiracarus Perty, 1841(Cryptostigmata : Euptyctima). By B. W. Parry. Type set by John Wright & Sons Ltd, Bristol and Printed by Henry Ling Ltd, Dorchester Bulletin of the British Museum (Natural History) Miscellanea Zoology series Vol 35 No 2 26 April 1979 The Bulletin of the British Museum (Natural History), instituted in 1949, is issued in fourscientific series, Botany, Entomology, Geology (incorporating Mineralogy) and Zoology,and an Historical series. Parts are published at irregular intervals as they become ready. Volumes will contain aboutthree hundred pages, and will not necessarily be completed within one calendar year. Subscription orders and enquiries about back issues should be sent to : Publications Sales,British Museum (Natural History), Cromwell Road, London SW7 5BD, England. World List abbreviation: Bull. Br. Mus. nat. Hist. (Zool.) Trustees of the British Museum (Natural History), 1979 ISSN 0007-1498 Zoology series Vol 35 No 2 pp 127-200British Museum (Natural History)Cromwell RoadLondon SW7 5BD Issued 26 April 1979 Miscellanea Contents PageThe dargyrome of the genus Euplotes (Hypotrichida, Ciliophora). By Michael A. Gates and Colin R. Curds 127 A redescription of types of six species of Neotropical Veronicellidae (Mollusca; Gastro-poda) in the British Museum (Natural History). By Jose Willibaldo Thome . . 135 A taxonomic study of six species of Upogebia Leach (Crustacea, Decapoda, Thalassinidea)in the collections of the British Museum (Natural History), London. By NguyenNgoc-Ho 147 Larval development of British prawns and shrimps (Crustacea : Decapoda : Natantia).2. Palaemonetes (Palaemonetes) varians (Leach, 1814) and morphological variation.By A. A. Fincham 163 A revision of the spider genus Brettus (Araneae : Salticidae). By F. R. Wanless . . 183 Notes on the osteology of the Arab horse with reference to a skeleton collected in Egypt by Sir Flinders Petrie. By Juliet Clutton-Brock and Richard Burleigh . . . 191 The dargyrome of the genus Euplotes(Hypotrichida, Ciliophora) Michael A. Gates and Colin R. Curds Department of Zoology, British Museum (Natural History), Cromwell Road, London SW7 5BD Introduction Since the advent of silver impregnation (Chatton & Lwoff, 1930) to reveal the infraciliature ofciliated protozoa, several previously undetected cortical characteristics have been postulated tobe of taxonomic value. Tuffrau (1960) was the first worker to apply silver-staining techniques tohypotrich ciliates of the genus Euplotes Ehrenberg, 1831,* concentrating mainly on the prominentventral ciliature. However, he also revealed the pattern of the fibrillar network of silver-lines thatcovers both the ventral and dorsal surfaces, introducing the term argyrome to describe the totalityof this feature, now known to mark the boundaries between adjacent subpellicular vacuoles(RufTolo, 1976a, 19766). Tuffrau classified the dorsal argyrome (hereafter, dargyrome) patternsinto three distinct types, and he applied this classification towards the resolution of taxonomicproblems involving several large, common and popular freshwater species. In particular, Tuffrau(1960) suggested that E. patella (Miiller, 1773) Ehrenberg, 1838 could be distinguished from E.eurystomus (Wrzesniowski, 1870) Kahl, 1932 by distinct differences in their dargyrome patterns. On the basis of a retrospective study of the genus, incorporating many taxonomic descriptionsthat had accumulated since the introduction of silver-impregnation techniques, Curds (1975)presented a refinement of Tuffrau's (1960) dargyrome classification, raising the number of typesto six (Fig. 1). Tuffrau's original classification was based essentially on the number of rows ofsilver-staining polygons (corresponding to subpellicular vacuoles) that occur between any twoadjacent kineties (rows of cilia). In Tuffrau's 'vannus' dargyrome type, there is only a single row(as in E. vannus (Miiller, 1786) Minkjewicz, 1901), while in his 'eurystomus' type, there are tworows, separated by an interkinetal vacuolar boundary. Curds (1975) retained the 'vannus' type,rechristening it 'single-vannus' (Fig. la), but he subdivided the 'eurystomus' type into threedistinct patterns, depending on the position of the interkinetal boundary. In the 'double-eury-stomus' type (Fig. Ib), that boundary is centrally situated, while in the two 'double-patella' types(Figs Ic, Id), it is displaced to either the left or the right, respectively. The classical species E.eurystomus possesses the 'double-eurystomus' dargyrome, while E. patella possesses the firstvariant (Fig. Ic) of the 'double-patella' dargyrome. Tuffrau's 'muscicola' dargyrome type wasconsidered by Curds to consist in a heterogeneous mixture of two types: the 'multiple' dargyrome(Fig. le), in which there are several rows of polygons between kineties (as in E. muscicola Kahl,1932), and the 'complex' dargyrome (Fig. If), in which the interkinetal space is irregularly sub-divided (as in E. elegans Kahl, 1932). The ramifications of this typology are not without consequence to the taxonomy of the genus.Dargyrome pattern is one of the few classical taxonomic attributes still considered to be invariantwithin species of the genus (Carter, 1972; Curds, 1975; Hill & Reilly, 1976) and it remains, forexample, one of the major distinguishing features applicable to the confusing assemblage ofcommon freshwater species which includes, in addition to the classical E. patella and E. eury-stomus, others such as E. aediculatus Pierson, 1943, E. plumipes Stokes, 1884, E. variabilisStokes, 1887 and E. woodruffi Gaw, 1939 (Pierson, 1943; Tuffrau, 1960; Pierson et al, 1968;Carter, 1972; Curds, 1975; Hill & Reilly, 1976; Curds, 1977). All of these species are of cirrotype-9 * It should be noted that contrary to the publications of several recent authors, the valid date of publication forthe genus Euplotes is 1831 (see Ehrenberg, 1831 : 12) not 1830 nor 1838. Furthermore, the 1830 date refers to thenominal publication date of the name Euploea for which the correct citation, according to Article 21 of the Inter-national Code of Zoological Nomenclature should be Euploea Ehrenberg, 1832. Bull. Br. Mus. not. Hist. (Zool.) 35 (2): 127-200 Issued 26 April, 1979 127 128 M. A. GATES AND C. R. CURDS a e Fig. 1 Dargyrome patterns of Euplotes: (a) single-vannus type; (b) double-eurystomus type;(c-d) double-patella types; (e) multiple type; (f) complex type. (i.e. they have 9 frontoventral cirri), and all of them have very similar cirral patterns on theirventral surface (Gates, 1976). This paper demonstrates that the subclassification of double dargyromes according to whetherthe interkinetal boundary is central (the 'double-eurystomus' type) or displaced to the right orleft (the 'double-patella' type) is invalid. Materials and Methods In March 1975, a clonal population was established in Toronto, Ontario, Canada, of a doubledargyrome, cirrotype-10 marine form, labelled QVANNQ (Gates, 1976), which was collectedin 1974 from the North Sea off the coast of Denmark and cultured at the British Museum (NaturalHistory). In April 1976, three subclones (1, 2, 3) of this clone were established at the latter insti-tution, and these were sampled at three separate times: A, 11 August 1976; B, 7 December 1976;C, 12 January 1977. These nine samples were silver-stained by a modification of the Chatton-Lwoff procedure (Chatton & Lwoff, 1930; Corliss, 1953; Frankel & Heckmann, 1968). Within the same microscope slide of a silver-stained preparation of subclonal sample B-l, forexample, are found not only typical 'double-eurystomus' specimens (Fig. 2), which are in themajority, but also occasionally a typical 'double-patella' specimen (Fig. 3), plus all of the inter- DARGYROME OF EUPLOTES 129 Fig. 2 Dargyrome of a specimen of subclone B-l of the marine cirrotype-10 Euplotessample, QVANNQ, showing a classical 'double-eurystomus' type of dargyrome. Fig. 3 Dargyrome of another specimen of subclone B-l from the same slide preparation,showing a classical 'double-patella' type of dargyrome. 130 M. A. GATES AND C. R. CURDSAIM CK RP Fig. 4 Diagram of the dorsal surface of a specimen of the QVANNQ Euplotes sample, illustratingthe measurement transect that provides the two sets of interkinetal distances (x x , y v and x 2 , y z )on either side of the central kinety (ck) that are used to obtain the interkinetal ratios, x^y^ andXz/y*, whose average provides a measure of dargyrome type for the specimen. The dorsal originof the adoral zone of membranelles (AZM) is also shown at the anterior of the specimen, thereference point is indicated by RP. mediate types. While these examples are suggestive, they are not, in themselves, sufficient toestablish the invalidity of a typology. Since evolution is the partitioning of variation, and as vari-ation is quantitative in nature, a detailed quantitative analysis is essential. As inspection of either Fig. 2 or Fig. 3 reveals, the position of the interkinetal boundary varieswith the region of the dorsal surface examined. To obtain an objective, repeatable measure ofthe position of that boundary within a given population of a double-dargyrome Euplotes species,attention must be focused on a restricted portion of the middle of the dorsal surface of well-stained and properly-oriented specimens. The origin of the adoral zone of membranelles (AZM)provides a well-defined reference point (see Fig. 4) on the dorsal surface of this species of Euplotes.This point can be used to locate and define the central kinety which is the second kinety lying tothe left of the reference point. Accordingly, the widths of the two interkinetal boundaries weremeasured on either side of the central kinety midway along each specimen. Using a Leitz Laborlux microscope with 100 x oil immersion objective and 10 x ocularsequipped with a 1-25 x drawing tube, the images of the points illustrated in Fig. 4 were recordedon acetate sheets with indian-ink and these were then projected onto millimetre-ruled linear graphpaper by means of a Leitz Diascriptor 4 projector. From these coordinate data, the two sets ofinterkinetal distances (x lt y l and x 2 , y^) determined by the placement of the two central inter-kinetal boundaries were calculated and the ratios xjy t and x 2 /y 2 formed. Each of these ratiosmeasures the placement of the interkinetal boundary on either side of the central kinety, and theiraverage provides a quantitative measure of the dargyrome of the specimen. Thus, the nature ofthe dargyrome on each specimen is represented by a single number, the average interkinetal ratio.To measure the dargyrome type of any given population, the mean interkinetal ratio (MIR) is DARGYROME OF EUPLOTES 131 calculated, based on 50 specimens for each sample, except series A-l, where only 19 specimenswere available. Comparisons among populations were made by means of standard analysis of variance tests,primarily the F-ratio test (Sokal & Rohlf, 1969). A 95% confidence level was used throughout.Conclusions were not affected by assuming that the average interkinetal ratio is normally dis-tributed within each population (as was verified to be true in one sample) : use of the arcsine trans-formation for ratios (Sokal & Rohlf, 1969) gave similar results to those presented here, whichare based on untransformed data. To facilitate comparisons, results are given in terms of the 95 %confidence intervals (on either side of the mean) for each sample, based on f-values, rather thanthe ^-ratios for each group of samples. Results An essential ingredient in any quantitative analysis of variation is an examination of the inherenterrors of measurement. Table 1 presents the results of measuring the same specimen 50 times,which gives a measurement error confidence interval for the MIR in the order of 0-015. Alsoshown are the results of measuring 50 specimens of each of two separate slide preparations of theB-l sample; it is clear that there are no differences among subsamples of this sample. Theseresults demonstrate, respectively, the precision and accuracy of the MIR as a measure of dargy-rome type. Table 1 Error analysis for the mean interkinetal ratio. Using the B-lsubclone, the same specimen was remeasured 50 times to assess theinherent error of measurement. To judge the accuracy of measurement,50 specimens on each of two separate slides of this same subclone weremeasured. In this and the two following tables, the mean (x), standarddeviation (s) and 95 % confidence interval (c.i.) are presented As Figs 2 and 3 clearly illustrate, there can be considerable variation from individual toindividual in dargyrome type. But to demonstrate the invalidity of the concept, it must be estab-lished that populations of individuals differ, not merely that individuals vary. Given the meaninterkinetal ratio of a population, it must be established, first, that the ratio is inherited, andsecond, that it is sufficiently variable that different subclones may have significantly differentratios. That is, if two individuals are derived from a parental clonal population, are their ratiosdifferent, and will those ratios be inherited by their asexual progeny ? Tables 2 and 3 present the results. For each clone, there are no significant differences in theMIR with time, over the period sampled (Table 2). This demonstrates that the MIR is inheritedwithin clones. If the results are regrouped by fixation date (Table 3), it is apparent that significantdifferences do exist among the three clones. Clone 1 is always larger in MIR than clone 3, andclone 2 is always intermediate ; the differences between clone 1 and clone 3 are significant at thelast two fixation times, B and C. This consistent and significant trend shows that different sub-clones may possess significantly different ratios. Discussion The results demonstrate that, although the asexual progeny of an individual inherits the dargy-rome type of the parent, different individuals may give rise to progeny which have significantly 132 M. A. GATES AND C. R. CURDS Table 2 Mean interkinetal ratios for the 9 subclones, arranged by clone.For each clone, there are no significant differences among the threedifferent sampling times (A, B, C) Clone x s c.i. Table 3 Mean interkinetal ratios for the 9 subclones,arranged by sampling time. Significantly differentclones within each sampling time are indicated byasterisks on the means Clone x c.i. different dargyrome types, as measured by the MIR. This form of quantitative uniparental in-heritance of the mean interkinetal ratio makes its use as a taxonomic criterion invalid. Morepoignantly, qualitative distinctions based on the same principle are likewise invalid : the 'double-eurystomus' and 'double-patella' dargyrome types do not exist as separate entities. They representextremes of a continuum of interkinetal ratios that exists within most large populations of doubledargyrome Euplotes. The typological fixation of the extremes of this continuum is to be deplored. The work of Frankel (1973, 1975) demonstrates the considerable independence of the ventraland dorsal surfaces of Euplotes. In another marine cirrotype-10 species, E. minuta Yocom, 1930,the distribution of ciliary units over the dorsal surface is stable, but there can be large variationsboth in the number of kinetics and in the number of cilia per kinety, while on the ventral surface,the number of frontoventral cirri (the cirrotype) remains constant, even in a basal-body deficientmutant. The present study is also based on a marine cirrotype-10 form, and the most parsimoniousinterpretation of our results is that other double dargyrome Euplotes do have a similar quantitativeuniparental inheritance of the MIR. In particular, we suggest that it applies equally well to thecirrotype-9 freshwater forms such as E. patella and E. eurystomus, which display similar inidvidualvariations in MIR (Gates, unpublished observations). In conjunction with the results of quantita-tive studies of the ventral cirral patterns of these forms (Gates, 1976), such an interpretation is ofobvious applicability to the alleviation of the taxonomic confusion which exists among freshwatercirrotype-9 Euplotes (see, for example, Curds, 1975; Hill & Reilly, 1976). The existence of individual variation in dargyrome type is not confined to samples of Euploteshaving double dargyromes (Gates, 1976, and unpublished observations). Among individuals of DARGYROME OF EUPLOTES 133 various single dargyrome forms, one may see not only the erratic 'reorganizing' dargyromes whichTuffrau (1960) noted in his E. mutabilis Tuffrau, 1960, now known to be fully interfertile withE. crassus (Dujardin, 1841) Kahl, 1932 (Genermont et al., 1976), but also occasional regions inwhich a double dargyrome pattern is present, or in which the interkinetal space is further sub-divided. The latter phenomenon also occurs in various double dargyrome samples, including E.harpa Stein, 1859. Indeed, among some double dargyrome forms, multiple or complex patternsoccur in restricted regions of the dorsal surface of a few individuals, while in E. moebiusi Kahl,1932 (Curds, 1974) and E. tegulatus Tuffrau, 1960 (Tuffrau, 1960) there is a more general compli-cation of the dargyrome in all specimens examined. Finally, some 'multiple' dargyrome clonalsamples yield a few specimens having classical 'complex' dargyromes, suggesting that the lattertype is only a variant of the former. While all of these variants and exceptions are rare, they are as suggestive as Figs 2 and 3.Indeed, they suggest that dargyrome types are not immutable, and that it is possible to suggestan evolutionary sequence from 'single' through 'double' to 'multiple' (with its variant, 'complex')dargyromes (Gates, 1976). That is, the direction of evolutionary change has been the further sub-division of the interkinetal space by the corresponding polymerization of subpellicular vacuoles(see Polyjansky & Raikov, 1976). The 'single' dargyrome occurs only in small to medium-sized marine species of cirrotype-10,and these forms have identical cirral patterns (Gates, 1976). The 'double' dargyrome is the mostcommon type, found in both marine and freshwater forms of all cirrotypes; it occurs amongspecies with a variety of cirral patterns and sizes ; and it is the most variable dargyrome. The'multiple' and 'complex' dargyromes are restricted to only a few species (Curds, 1975). The common occurrence and the variable nature of the 'double' dargyrome has led to the crea-tion of subcategories which were presumed by taxonomists to be stable within 'species' (Curds,1975). Our results demonstrate the invalidity of the subdivision using this type of dargyrome.Although descriptive of particular clones, the 'double-patella', 'double-eurystomus' and 'complex'distinctions, should not be used in assessing taxonomic affinities . Because of the quantitativeuniparental inheritance of dargyrome type, these categories are not descriptive of populations ofEuplotes, even over short periods of time. Accordingly, we propose to modify Tuffrau's (1960)original classification along the more descriptive lines suggested by Curds (1975). The dargyromeof Euplotes should be classified as either 'single', 'double' or 'multiple'. Acknowledgements The senior author is grateful to the National Research Council of Canada for financial supportthrough a Postdoctorate Fellowship, and to the Trustees of the British Museum (Natural History)and of the Culture Centre of Algae and Protozoa for providing research facilities and space. References Carter, H. P. 1972. Infraciliature of eleven species of the genus Euplotes. Trans. Am. microsc. Soc. 91 : 466-492. Chatton, E. & Lwoff, A. 1930. Impregnation, par diffusion argentique, de 1'infraciliature des cilies marins et d'eau douce, apres fixation cytologique et sans desiccation. C. r. Seanc. Soc. Biol. 104 : 834-836.Corliss, J. 0. 1953. Silver impregnation of ciliated protozoa by the Chatton-Lwoff technic. Stain Technol. 28 : 97-100.Curds, C. R. 1974. Description of three species of Euplotes (Protozoa : Ciliatea). Bull. Br. Mus. nat. Hist. (Zool.) 27: 113-125.1975. A guide to the species of the genus Euplotes (Hypotrichida, Ciliatea). Bull. Br. Mus. nat. Hist. (Zool.) 28: 1-61. 1977. Notes on the morphology and nomenclature of three members of the Euplotidae (Proto- zoa : Ciliatea). Bull. Br. Mus. nat. Hist. (Zool.) 31 : 15-26.Ehrenberg, C. G. 1831. Animalia Evertebrata exclusis Insectis. In F. G. Hemprich and C. G. Ehrenberg.Symbolae Physicae seu Iconis et Descriptiones Animalium Evertebratorum. Sepositis Insectis. Beroliniex officina Academica. 126 pp. 1 34 M. A. GATES AND C. R. CURDS Frankel, J. 1973. A genically determined abnormality in the number and arrangement of basal bodies in a ciliate. Devi Biol. 30 : 336-365.1975. An analysis of the spatial distribution of ciliary units in a ciliate, Euplotes minuta. J. Embryol. exp. Morphol. 33 : 553-580. & Heckmann, K. 1968. A simplified Chatton-Lwoff silver impregnation procedure for use in experi- mental studies with ciliates. Trans. Am. microsc. Soc. 87 : 317-321.Gates, M. A. 1976. Morphometric Taxonomy of the Genus Euplotes. Ph.D. Thesis, University of Toronto, Toronto, Ontario, Canada. 269 pp.Genermont, J., Maghelon, V. & Tuffrau, M. 1976. Donnees exp6rimentales relatives au probleme de 1'espece dans le genre Euplotes (Cilies Hypotriches). Protistologica 12 : 239-248.Hill, B. F. & Reilly, J. A. 1976. A comparative study of three fresh-water Euplotes species (Ciliophora, Hypotrichida). Trans. Am. microsc. Soc. 95 : 492-504.Pierson, B. F. 1943. A comparative morphological study of several species of Euplotes closely related to Euplotes patella. J. Morph. 72 : 125-157.Gierke, R. & Fisher, A. L. 1968. Clarification of the taxonomic identification of Euplotes eurystomus Kahl and Euplotes aediculatus Pierson. Trans. Am. microsc. Soc. 37 : 306-316.Polyjansky, G. I. & Raikov, I. B. 1976. Polymerization and oligomerization phenomena in the protozoa. Trans. Am. microsc. Soc. 95 : 314-326.Ruffblo, J. J. 1976a. Fine structure of the dorsal bristle complex and pellicle of Euplotes. J. Morph. 148 : 469-488.1976&. Cortical morphogenesis during the cell division cycle in Euplotes: an integrated study using light optical, scanning electron and transmission electron microscopy. /. Morph. 148 , 489-528.Sokal, R. R. & Rohlf, F. J. 1969. Biometry. W. H. Freeman, San Francisco. 776 pp.Tuffrau, M. 1960. Revision du genre Euplotes, fondee sur la comparaison des structures superficielles. Hydrobiologia 15 : 1-77. Manuscript accepted for publication 5 January, 1978 A redescription of types of six species of NeotropicalVeronicellidae (Mollusca; Gastropoda) in the BritishMuseum (Natural History)* Jose Willibaldo Thome Museu Rio-Grandense de Ciencias Naturals, Brazil Resumo Com base no exame dos exemplares tipos depositados nas colecoes do Museu Britanico de HistoriaNatural, Londres, Inglaterra, sao redescritas, destacando-se os caracteristicos especificos validos, asseguintes especies: Vaginula cordillerae Simroth, 1914, Vaginula fusca Heynemann, 1885, Veronicellalaevis Blainville, 1817, Vaginula nesiotis Simroth, 1914 e Vaginula nigra Heynemann, 1885, bem comoum paralectotipo de Vaginula columbiana Simroth, 1914. Introduction This publication is part four of a series in which the types of neotropical Veronicellidae areredescribed; three parts have already been published (Thome, I969a, 19696, 1970). Types of sixspecies in the British Museum (Natural History) are considered here and some new features ofthe external and internal morphology are described. It is the opinion of the author that thesecharacters are important for the correct diagnosis of these species and a full discussion of theirsignificance can be found in Thome (1969a). Vaginula cordillerae Simroth Vaginula cordillerae Simroth, 1914 : 303-305, pi. 12, figs 50-53.Cylindrocaulus fuhrmanni Hoffmann, 1925 : 237 (partini), non Simroth. HOLOTYPE. BM(NH) Reg. No. 1928.8.27.26. TYPE LOCALITY. 'Argelia Cafetal' (east mountain ridge), Columbia - at 1600 m. LEG. Dr O. Fuhrmann (no date). The specimen was in good condition; it had been opened longitudinally along the dorsal surface,but all the organs remaining in situ. EXTERNAL MORPHOLOGY (PI. 1, figs 1-3) Size. Length: 59mm; breadth: 19mm; height: 12mm; right hyponoyum width: 7-4 mm;sole width: 6-2 mm: distance of female opening from anterior end: 32 mm, from posterior end:23 mm, from pedal groove: 2-3 mm. Description. Animal medium size, with a greater width than height; outline elliptical in dorsalview and specimen not arched. No turn dark grey with light brown shading; darker spots cor-respond to the position of mucous pores. Perinotum light brown, conspicuous, sharpened andslightly upturned. Hyponota grey, as the notum, and devoid of dark spots. Sole light brown with-out median line. Position of the female opening is about 1/3 of the hyponotum from pedal grooveand slightly posterior to the mid-point of the body length. Circular anus situated to the right ofsagittal plane and extending a little beyond the pedal groove; closed by a small thick plate, andcompletely covered by the posterior extension of the foot. This extension is devoid of pigmentation.Simroth (1914) describes coloration as follows: 'Der ganze Ton ist mit Ausnahme der blassen * Contribution No. 4, in series 'Redescription of types of Neotropical Veronicellidae (Mollusca; Gastropoda)'. Bull. Br. Mus. nat. Hist. (Zool.) 35 (2): 127-200 Issued 26 April, 1979 136 j. w. THOME Sohle schwarzlich chocoladen-braun, durchaus einfarbig, kaum dass das Perinotum eine Spurheller bleibt. Hie und da 1st auf dem Notum eine hellere ockerige rundliche Stelle von hochstens1 mm Durchmesser mit einem schwarzen Punkt in der Mitte, einem Driisentuberkel. Sonst ohneAbzeichen. Das Hyponotum das vom Pigment bis zur Grenze an der Fussrinne gleichmassigbedeckt ist, erscheint ganz feinkornig. Ebenso das Notum, nur dass sich hier in regelmassigenAbstanden von ca. 1 mm deutlich etwas grossere rundliche Korner erheben, die als dunkle Punktehervortreten, ohne doch tief schwarz zu sein.' INTERNAL MORPHOLOGY (Figs 1-3, 15) Digestive system. Anterior intestinal loop covered by a lobe of the digestive gland, which is4-0 mm wide. Rectum penetrating body wall near the oviduct and above it (Fig. 2).Nervous system. The pedal nerves originate close together and extend in this manner for half thelength of the animal; then they diverge but continue parallel to the posterior end. The pedalnerves are not attached to the body wall until they reach the aorta. Total length of pedal nerves :35-0 mm; diverge for 20-0 mm; maximum distance separating the parallel nerves: 2-0 mm;meeting aorta at 8-5 mm. Pedal gland. Cylindrical, flattened, loose and coloured light yellow. Appears to be dispropor-tionally long for the size of the animal. Outside zone clearly delimited up to the distal end, wheredelimitation is lost. At distal end, inner zone of the gland with a narrow longitudinal furrow.Length in natural position: 16-5 mm; distended: 18-0 mm; width: 1-7 mm (Fig. 1).Reproductive system. Spermatheca pear-shaped, attached at the swollen end to a thick and well-developed duct ( = spermathecal stalk). The duct fuses with the oviduct inside the body tegument.Canalis junctor well developed and coiled ; attached to the Spermatheca at the narrowest section(Fig. 2). Penial gland with a small conical papilla. Papilla with roughened surface and blunt apex, length5-5 mm, maximum diameter 2-7 mm. Penial gland with 18 uniform non-bifurcated tubulardiverticula. These are tightly coiled and are sheathed by a thick pellicle in the proximal region(Fig. 3). Each diverticulum has a diameter of 0-5 mm and a maximum length of 6-0 mm. Total length of penis is 16-0 mm, with a maximum diameter of 1-6 mm, consisting of a shortconical stalk, only 1-5 mm 'long and a long glans which is attached to the pointed region ofstalk. Base of glans slightly flattened, on one side two flaps which are somewhat folded andnotched basally ; while on the reverse the glans is fused with the stalk and is delimited only by atransversal rib (Fig. 1 5). The remaining region of the glans is cylindrical, with the distal end havinga rhomboid apex and a median opening. COMMENTS Simroth's (1914) extensive description concentrated predominantly on structures of very littlespecific value and the illustrations provide little additional information. The synonymy proposedby Hoffman (1925) will be discussed in a later paper. Vaginula fusca Heynemann Vaginula fusca Heynemann, 1885 : 6-7, pi. 1, figs 1-3. Cylindricaulus fuscus (Haynemann); Hoffmann, 1925 : 157, 208, 238-239, pi. 5, figs 45d, 7 (partim). HOLOTYPE. BM(NH) Reg. No. 1896.6.5.72. TYPE LOCALITY. Rio de Janeiro, Guanabara, Brazil. LEG. Dr Cunningham in 1867; presented to the museum by the Lords of the Admiralty. The specimen was well preserved both for colour and internal anatomy; previously it had notbeen dissected. The penis and the penial gland were removed and placed in a small tube in the jarwith the specimen. EXTERNAL MORPHOLOGY (PI. 2, figs 1-3) Size. Length: 81 mm; breadth: 30mm; height: 21 mm; right hyponotum width: 12-7 mm; sole REDESCRIPTION OF VERONICELLIDAE 137 Figs 1-3 Vaginula cordillerae Simroth (Holotype: BM(NH) Reg. No. 1928.8.27.26): 1. Pedalgland, dorsal view; 2. Organs close to the female genital opening, dorsal view; 3. Penial gland. Figs 4-6 Vaginula fusca Heynemann (Holotype: BM(NH) Reg. No. 1896.6.5.72): 4. Pedal gland,dorsal view; 5. Organs close to the female genital opening, dorsal view; 6. Penial gland, lakingdistal ends of tubular glands. width: 14-6 mm; distance of female opening from anterior end: 37mm, from posterior end:28-5 mm, from pedal groove: 3-2 mm. Description. Animal large, with a slightly greater width than height; outline elliptical indorsal view and specimen scarcely arched above ventral region. Mantle thick and hard. Notumbrown with irregularly distributed black pigmentation; pigmentation a little denser on the pos-terior and right sides, while in the median region a thin, irregular line remains. Perinotum whitishand devoid of pigmentation, sharpened. Hyponota whitish and without pigmentation, positioninclined becoming almost vertical. Sole whitish, wide and with a very distinct median line. Femaleopening about 1/4 distant from pedal groove and posterior to mid-point of body length. Circularanus situated to the right of sagittal plane, inside the hyponotum, but beyond the pedal groovewith which it is in contact in the mid-region; closed by a well-developed opercular blade andcompletely covered by the posterior foot end. End of foot wrinkled and devoid of pigmentation. INTERNAL MORPHOLOGY (Figs 4-6, 18) Digestive system. Anterior intestinal loop covered by a lobe of the digestive gland, which is 6-5 mm wide and with the loose extremity folded forwards. Rectum penetrating body wall near to the oviduct and above it (Fig. 5). Nervous system. The pedal nerves have separate origins and diverge for the first 15-0 mm, then proceed in parallel till the posterior region of the body cavity. Total length: 45-0 mm; maximum 138 j. w. THOME distance separating nerves: 11-0 mm. Pedal nerves loosely attached to the foot sole and approachclose to the aorta beneath the pedal ganglion. Nerves infested with nematodes.Pedal gland. Thin, very flattened, loose and coloured yellow. Outer zone wide, clearly delimitedfor the majority of its length. Length in natural position: 11-0 mm; distended: 13-0 mm; width:2-0 mm (Fig. 4). Reproductive system. Spermatheca pear-shaped, sessile, fusing with the oviduct inside the tegu-ment. Canalis junctor short and thick; attached to the spermatheca at the pointed extremity closeto the tegument (Fig. 5). Penial gland with a conical papilla that is 2- 1 mm long and with maximum diameter of 3-0 mm.Papilla without nipple, but showing a slight constriction at apex. Penial gland with 34 non-bifurcated or differentiated diverticula. Each diverticulum having a diameter of approximately0-6 mm and a maximum length of between 50 and 60 mm, except for one which is 7-0 mm. Total length of penis is 7-0 mm and a width of 2-1 mm with a maximum thickness of 0-8 mm;possessing a short conical stalk extending into a slightly flattened glans. Glans is S-shaped withwell-developed lateral flaps, base marked on one surface by a transversal rib. Concave face of thefirst curve of the S and convex face of the second are smooth and flat. The opposite face of thefirst curve is at first enlarged, rapidly becoming slender and continuing through the second as arib between the flaps. A slender and crenulate lip covers the opening at the tip of the penis. COMMENTS In the original description only data on external morphology were presented. Hoffmann's (1925)redescription was still insufficient for an accurate identification, and the illustration of the peniswas particularly poor. The synonymy proposed by Hoffmann will be discussed in a further work.Divergence between the measurements given in the different descriptions can be attributed tovariations in methods employed. Veronicella laevis Blainville Veronicella laevis Blainville, 1817 : 440-442, pi. 2, figs IV (1/2).Belocaulus sloanei Hoffmann, 1925 : 249-250 (partim), non Cuvier. HOLOTYPE. BM(NH) Reg. No. 196852-W.TYPE LOCALITY. Unknown.LEG. Unknown, no date. The specimen was preserved in alcohol and discoloured. No anatomical dissection had beenundertaken, in spite of an irregular longitudinal incision present in the posterior dorsal region ofthe notum. A piece of the very hard albumen gland had been removed and was found associatedwith the specimen ; the remainder was found inside the specimen. There was also a short longi-tudinal incision in the anterior region of the notum, limited damage to the anterior sole regionand a circular hole in the pedal groove, near the anus. Three labels were found inside the glass:a strip of paper written : '12. Veronicella laevis Blainv. Type.' ; a rectangular piece of paper, writtenin two lines: ''Veronicella laevis BL. - Jamaica Mus. Sloane'; a larger rectangular piece of paper,written in five lines: 'HOLOTYPE- Veronicella laevis Blainville 1817 -Jamaica Mus. Sloane -Sec. Journ. de Physique, LXXXV, dec. 1817, 442 -Sec. Cockerell, The Conchologist, Vol. 2,No. 8, Dec. 1893, p. 217'. The slug was dissected with a cut along the left pedal groove. Only the penis and the penialgland were removed and these were placed in a small tube associated with the specimen. Preser-vation of internal organs was good. EXTERNAL MORPHOLOGY (PI. 1, figs 4-6) Size. Length: 64mm; breadth: 26mm; height: 10-5 mm; right hyponotum width: 6-4 mm;sole width: 6-9 mm; distance of female opening from anterior end: 27-5 mm, from posterior end:20-5 mm, from pedal groove: 2-2 mm. REDESCRIPTION OF VERONICELLIDAE 139 Plate 1 Figs 1-3 Vaginula cordillerae Simroth (Holotype: BM(NH) Reg. No. 1928.8.27.26). Dorsal, lateraland ventral view, x 1-708. Figs 4-6 Veronicella laevis Blainville (Holotype: BM(NH) Reg. No. 1 96852- W). Dorsal, lateral andventral view, x 1-5. 140 J. W. THOME Description. Animal medium size, with a greater width than height, slightly arched dorsally,outline oblong with extremities quite pointed. Mantle thin. Notum, as well as the remaining areaof the body, whitish and discoloured. Perinotum sharpened and keeled. Hyponota almosthorizontal. Sole slightly more yellowish than other areas of the body and devoid of median line.Position of female opening distant about 1/3 of the hyponotum from the pedal groove andposterior to the mid-point of the body. Circular anus extends from the pedal groove into thehyponotum and to the right of the sagittal plane; partially closed by a small thin operculateblade, and partially covered by loose posterior region of the foot. The latter is not papillose orpigmented. INTERNAL MORPHOLOGY (Figs 7-9, 17) Digestive system. Anterior intestinal loop covered by a lobe of the digestive gland, which is2-5 mm wide. Rectum penetrating body wall near the vagina and above it (Fig. 8).Nervous system. Pedal nerves originate together, run parallel and unattached for 1/6 of their lengthuntil they diverge. Then adhering to the tegument extend almost parallel to the end of the bodycavity where they disappear into the tegument. Total length of pedal nerves: 35-0 mm; divergentfor 29-0 mm; maximum distance separating parallel nerves: 5-5 mm; meeting aorta at 2-5 mm.Pedal gland. Small, flattened, loose and coloured yellow. External zone poorly delimited and onlyrecognizable in the proximal region. A median concavity visible on the dorsal face at the distalregion. Length: 5-2 mm; width: 1-4 mm (Fig. 7). Reproductive system. Spermatheca subspherical, small, with a thick, rigid and very long duct.The latter fuses with the oviduct just prior to the latter joining a short vagina outside the tegu-ment. Canalis junctor short, straight, thin, penetrating the duct at about 1/5 from the distal end,closer therefore to the spermatheca (Fig. 8). Penial gland small, with a minute rhomboid conical papilla 0-7 mm long and 0-9 mm wide atthe base. Sixteen external diverticula on the penial gland each up to 4-5 mm long and with dia-meter of 0-3 mm; these differ little from the 11 internal diverticula which are up to 2-5 mm longand 0-3 mm diameter. All diverticula are wrinkled and of the same colour (Fig. 9). Total length of penis 13-5 mm with a diameter of 1-0 mm, except for a swelling at the distalend where there is an extrovertion of conical cavernous tissue, with a maximum diameter of1*5 mm. Penis smooth, elongated and cylindrical with the deferens opening at the tip of the extro-vertion (Fig. 17). COMMENTS This species presents a polemic problem, for Blainville (1817) in the original description, men-tioned the presence of '. . . vers le tiers posterieur, un rudiment de coquille, sans aucune trace dedisque ou de bouclier' (p. 442) and stated on the same page : 'On ignore tout-a-fait sa patrie, etmeme comment il est arrive dans la collection', referring to material in the British Museum(Natural History) collection. On the basis of these statements, and without ever checking thetype specimen, many authors have rejected the doubted validity of this species or included it inthe synonymy of V. sloanei (Cuvier, 1817 : 411). The latter must, however, be considered as anindependent species. Blainville (1817) described the species Veronicella laevis and established the genus Veronicella,on the basis of a single specimen in the British Museum (Natural History) collection, but with noreference to its origin. Examination of the type specimen preserved in that Institution permitscomparison with Blainville's drawings and description; compare plate I, figs 5 (lateral) and 6(ventral) with plate II, drawings 1 and 2 by Blainville (1817). The conspicuous anus was inter-preted by Blainville as the opening of pneumostoma and the circular hole a little ahead of theanus, which is an artifact, was thought by Blainville to be the anus, but these features togetherwith the anterior tentacles inside the anterior edge of the mantle and the penis close to the righttentacle, all confirm Blainville's description. Finally the reference to an internal shell in Blainville,at the median posterior dorsal region and visible through the notum, can be attributed to thepresence in that region of the large, but abnormally hardened, albumen gland. Blainville (1817 : 441) comments: 'le dos est assez eleve, convexe dans les deux sens et un peuplus gibbeux ou eleve a la partie posterieure', these features are visible. There follows: 'C'est a ce REDESCRIPTION OF VERONICELI IDAE 141 point, ou environ au tiers posterieur, que Ton trouve dans 1'interieur de la peau un rudiment decoquille que Ton apercoit a travers la peau, fort mince en cet endroit', which corresponds perfectlyto the rectangular, thin, still portion of the hardened albumen gland, which Blainville inter-preted as an internal rudimental shell. Blainville' s mistake is quite understandable if we considerthat he was the first to describe a slug of this gastropod group, the only one that does not present,in any phase of its ontogeny, any trace of shell. This redescription should remove the polemic nature of the species particularly that concernedwith the validity of Blainville's species and, therefore, the priority of the taxon, which is the'type-species' of the genus Veronicella Blainville, 1817. The latter being the 'type-genus' of thefamily Veronicellidae Gray, 1840. A more detailed taxonomic and synonymic discussion on thisproblem will be presented in a forthcoming paper. Vaginula nesiotis Simroth Vaginula nesiotis Simroth, 1914 : 297-300, pi. 12, figs 36-42. Cylindrocaulus olivaceus var. jamaicensis Hoffmann, 1925 : 233-234 (partim), non Cockerell. HOLOTYPE. BM(NH) Reg. No. 1928.8.27.28. TYPE LOCALITY. Kingston, Jamaica. LEG. Dr O. Fuhrmann (purch. Dr O. Fuhrmann, 1928), no date. The specimen has been so damaged that the presence of the mantle and foot sole only permitrecognition as a member of the family Veronicellidae (PI. 2, fig. 7). All other organs have beencompletely macerated. Nevertheless, it is possible to verify that the specimen was opened at thenotum. Thus Simroth's original, but incomplete, description is the only means for reidentificationof the species. The synonymy proposed by Hoffmann (1925) is unreliable as it is based on in-complete morphological data. Vaginula nigra Haynemann Vaginula nigra Haynemann, 1885 : 7, pi. 1, figs 4-5.Phyllocaulus gayi (Fischer); Hoffmann, 1925 : 244-245 (partim). LECTOTYPE. BM(NH) Reg. No. 1876.9.30.2, selected here.TYPE LOCALITY. Unknown, but probably Chile.LEG. E. Gerrard Junior, no date. Two complete specimens were present and these had not been dissected. The largest was selectedas lectotype, because of its better preservation with only the penial gland abnormally soft. Theparalectotype was poorly fixed; the penis was partially everted, and macerated while the otherorgans were also soft. Both specimens have the shiny appearance and soft consistency typical ofslugs that were dying or already dead before fixation. EXTERNAL MORPHOLOGY (PI. 3, figs 1-3) Size. Length: 74mm; width: 27mm; height: 14mm; right hyponotum width: 7-9 mm; solewidth: 7-9 mm; distance of female opening from anterior end: 26mm, from posterior end:36 mm, from pedal groove: 2-4 mm. (Note: dimensions of the paralectotype in the same order:68, 27, 14, 9-9, 8-5, 25-5, 31-5 and 2-4 mm.) Description. Animal large, with a greater width than height; outline oblong; specimen notarched, but of a soft consistency, that has contributed to the production of a cylindroid form.Colour grey, with brown staining, notum densely covered with black spots which are uniformlydistributed. Perinotum not clearly defined and recognized only by a line separating the pigmentednotum from the non-pigmented hyponota. The latter has a dark grey uniform colour with palebrown spots in some areas, especially near the female opening. Sole pale, without pigmentationand with a median line. Position of female opening is about 1/3 of the hyponotum from the pedal 142 j. w. THOM Figs 7-9 Veronicella laevis Blainville (Holotype: BM(NH) Reg. No. 1 96852- W): 7. Pedal gland,dorsal view; 8. Organs close to the female genital opening, dorsal view; 9. Penial gland, lakingdistal ends of tubular glands. Figs 10-12 Vaginula nigra Haynemann (Lectotype : BM(NH) Reg. No. 1 876.9. 30.2) : 1 0. Pedal gland,dorsal view; 11. Organs close to the female genital opening, dorsal view; 12. Penial gland, lakingdistal ends of tubular glands. Figs 13-14 Vaginula columbiana Simroth (Paralectotype : BM(NH) Reg. No. 1 928.8.27.27) :13. Pedal gland, dorsal view; 14. Organs close to the female genital opening, dorsal view. groove and well anterior to mid-point of body length. Circular anus situated to the right of sagittalplane, inside the hyponotum, but in contact with the pedal groove; it is almost closed by an oper-culate blade and completely covered by the loose tip of the foot ending. The latter is papillousand heavily pigmented black. INTERNAL MORPHOLOGY (Figs 10-12, 16) Digestive system. Anterior intestinal loop covered by a lobe of the digestive gland, which is 5-0 mmwide. Rectum penetrating body wall 7-0 mm behind the oviduct and slightly above it (Fig. 11).Nervous system. The pedal nerves originate close together and extend parallel until meetingaorta; then diverging for 15-0 mm and becoming parallel until the posterior end of the bodycavity. Nerves attached to the tegument. Total length of pedal nerves: 44-0 mm; maximum dis-tance separating the nerves: 4-0 mm; meeting aorta at 4-5 mm. Pedal gland. Thick, somewhat flattened, loose and coloured yellow. No external zone observed.Length in natural position: 8-5 mm; distended: 10-0 mm; width: 2-0 mm (Fig. 10). Plate 2 Figs 1-3 Vaginula fusca Haynemann (Holotype: BM(NH) Reg. No. 1896.6.5.72). Dorsal, lateraland ventral view, xl-25. Figs 4-6 Vaginula columbiana Simroth (Paralectotype : BM(NH) Reg. No. 1928.8.27.27). Dorsal,lateral and ventral view, x 2-06 - x 2-06 - x 2-09. Fig. 7 Vaginula nesiotis Simroth (Holotype : BM(NH) Reg. No. 1928.8.27.28). View of the dried andmacerated remaining portion, x 1-74. 144 j. w. THOM 1 Plate 3 Figs 1-3 Vaginula nigra Heynemann (Lectotype: BM(NH) Reg. No. 1876.9.30.2). Dorsal, lateraland ventral view, x 1-40 - x 1-40 - x 1-35. Reproductive system. Spermatheca egg-shaped exhibiting laterally, close to the broadest end, asmall cylindrical swollen region; with fine walls, sessile, joining the oviduct inside the tegument.The thick and short canalis junctor is attached to Spermatheca at the tip of the cylindrical swollenregion (Fig. 11). Penial gland small, with a tiny, conicle, pointed papilla, but without nipple.Papilla 0-5 mm long and with 0-5 mm diameter at the base. Penial gland with 17 external diverticula each up to 30-0 mm long and 0-3 mm in diameter;there are 9, light coloured, internal diverticula each up to 20-0 mm long and 0-2 mm in diameter.Distinction between the internal and external diverticula is not very sharp ; no bifurcations wereseen; all are very thin at the base, soft and flattened (Fig. 12). Penis is 9-5 mm long, 3-5 mm wide and 2-3 mm thick, with a short conical stalk, from whicharises a fleshy and wide spathe. The spathe is smooth with one edge being thicker than the otherand showing lengthwise on the outer surface a median ridge, resembling the spine of a book.The glans is cylindrical with the distal region pointed, with the opening of the deferens at the tip;glans attached near to the base of the spathe. The spathe is longer than the glans and slightlyencloses it, yet both remain separate. Spathe length: 8-0 mm and 0-8 mm thick. Length of glans:7-0 mm, with a maximum diameter of 1-9 mm (Fig. 16). COMMENTS On the basis of the original description by Heynemann (1885) only the two specimens could berecognized, although the species was indeterminate. The synonymy proposed by Hoffmann (1925)will be discussed in a forthcoming paper. Vaginula columbiana Simroth Vaginula columbiana Simroth, 1914 : 300-303, pi. 12, figs 43-45.Vaginula columbiana Simroth; Thome", 1970 : 76-78, figs 8-14. REDESCRIPTION OF VERONICELLIDAE 145 PARALECTOTYPE. BM(NH) Reg. No. 1928.8.27.27. LOCALITY. Columbia. LEG. Dr O. Fuhrmann, no date. The specimen was preserved in alcohol and it had previously been opened longitudinally along thenotum. The penis and the penial gland were missing. The specimen was very young and immature. EXTERNAL MORPHOLOGY (PI. 2, figs 4-6) Size. Length: 41 mm; width: 10- 5 mm; height: 6mm; right hyponotum width: 4-1 mm; sole width: 2-7 mm; distance of female opening from anterior end: 23mm, from posterior end: 16 mm, from pedal groove: 1-3 mm. Description. Shape and colour identical to that described for the Lectotype (Thome, 1970). In this specimen there is a single outgrowth on the perinotum at the posterior end (PL 2, figs 4 and 6). INTERNAL MORPHOLOGY (Figs 13-14) Digestive system. Anterior intestinal loop covered by a lobe of the digestive gland, which is3-5 mm wide. The material was a little damaged and the typical dichotomyzation of the lobe wasnot observed. Rectum penetrating body wall close to and slightly above the accessory bursa,which separates it from the vagina (Fig. 14). 15 16^- 17 18 Penes of: Fig. 15 Vaginula cordillerae Simroth (Holotype: BM(NH) Reg. No. 1928.8.27.26).Fig. 16 Vaginula nigra Heynemann (Lectotype: BM(NH) Reg. No. 1876.9.30.2).Fig. 17 Veronicella laevis Blainville (Holotype: BM(NH) Reg. No. 1 96852- W).Fig. 18 Vaginula fusca Heynemann (Holotype: BM(NH) Reg. No. 1896.6.5.72). 146 J. W. THOM6 Nervous system. The pedal nerves originate close together and run parallel almost to the end of thebody cavity. They diverge very little and then only at the posterior end. They are not attached tothe body wall until posterior to the point where they meet the aorta. Total length of pedal nerves:29-0 mm; divergent for: 6-0 mm; maximum distance separating the nerves: 0-5 mm; meetingaorta at 6-0 mm. Pedal gland. Flattened and coloured yellow. External zone light coloured and enlarged to thesecond fold but then indistinct. Length in natural position: 8-0 mm; distended: 10-0 mm; width:1-3 mm (Fig. 13). Reproductive system. Spermatheca egg-shaped, but quite pointed; attached to a cylindrical duct,and joins the oviduct posterior to the well-developed vagina which penetrates the body wall.Canalis junctor short and attaches to spermatheca near to its narrowest point. Between vagina andthe rectum there is an accessory bursa, which is bell-shaped (Fig. 14).The penial gland and the penis were not present in the specimen examined. COMMENTS The specimen is considered as a paralectotype because it was part of Simroth's (1914) originaltype species. This specimen was referred to by Simroth as being from Bogota. It is registered inthe museum as being from Columbia and having been purchased from Dr O. Fuhrmann in 1928.Both the external and internal morphology permit this specimen to be specifically identified inspite of the absence of the penis and the penial gland and the sexual immaturity. Acknowledgements The author is indebted to John F. Peake of the Department of Zoology, British Museum (NaturalHistory), for revision of the manuscript and also to the staff of the Mollusca Section for facilitatingaccess to the material and bibliography as well as for kind and constant help. I am indebted to my wife who took all the photographs and helped me with the bibliography. The author was granted a scholarship from the 'Alexander von Humboldt-Stiftung', BadGodesberg, Germany, which permitted a visit to London. References Baker, H. B. 1925. Nomenclature of Veronicellidae (Vaginulidae). Nautilus 39 (1) : 13-18. 1956. Family names in Pulmonata. Nautilus 69 (4) : 128-129. Bin I in i lie, H. M. D. de 1817. Memoire sur quelques Mollusques Pulmobranches. /. Phys. Chim. Hist. nat., Paris 85 (11), pi. 2, fig. IV (1/2), and 85 (12) : 437-444. Cockerell, T. D. A. & Collinge, W. E. 1893. A check-list of the slugs, with appendix and notes. (Continu-ation.) Conchologist. Land. 2 (8) : 185-232. Cuvier, G. 1817. Le Regne Animal distribue d'apres son organisation, . . ., vol 2, xviii + 532 pp. Paris.Heynemann, D. F. 1885. Ueber Vaginula-Arten im British Museum (Natural History) in London. Jb. dt. malakozool. Ges. 12 : 1-16, pis 1-2.Hoffmann, H. 1925. Die Vaginuliden. Ein Beitrag zur Kenntnis ihre Biologic, Anatomic, Systematik, geographischen Verbreitung und Phylogenie. (Fauna et Anatomia ceylanica, in, n. 1.) JenaZ. Naturw. 61 (1/2) : 1-374, pis 1-11.Simroth, H. 1914. Beitrag zur Kenntnis der Nacktschnecken Columbiens, Zugleich eine Uebersicht ueber die neotropische Nacktschnecken-Fauna ueberhaupt. (In Voyage d'exploration scientifique en Colom- bie.) M6m. Soc. neuchdt. Set. nat. 5 : 270-341, pis 11-14.Thome, J. W. 19690. Redescricao dos tipos de Veronicellidae (Mollusca, Gastropoda) neotropicais : I. Esp6cies depositadas no 'Zoologisches Museum' de Kiel, Alemanha. Iheringia, zool. 37: 101-111, 21 figs.19696. Erneute Beschreibung neotropischer Veronicellidae-Typen (Mollusca, Gastropoda). II. Arten aus der Sammlung des Senckenberg-Museum in Frankfurt a.M. Arch. Molluskenk., 99 (5/6) : 331- 363, pis 6-13. 1970. Redescricao dos tipos de Veronicellidae (Mollusca, Gastropoda) neotropicais: in. Especies depositadas no 'II. Zoologisches Institut und Museum der Universitaet' de Gottingen, Alemanha. Iheringia, zool. 38 : 73-88, 28 figs. Manuscript accepted for publication 8 October, 1974 A taxonomic study of six species of Upogebia Leach(Crustacea, Decapoda, Thalassinidea) in thecollections of the British Museum (NaturalHistory), London Nguyen Ngoc-Ho* Faculty of Science, University of Saigon, Vietnam Synopsis A recent study of unnamed specimens of Upogebia in the collections of the British Museum (NaturalHistory) has enabled me to identify the following six species from among this material : Upogebia africanaOrtmann, Upogebia brasiliensis Holthuis, Upogebia carinicauda (Stimpson), Upogebia darwini (Miers),Upogebia issaeffi (Balss) and Upogebia spinigera (Smith). Detailed descriptions are given here of the twospecies Upogebia africana Ortmann and Upogebia issaeffi (Balss) as previous accounts are inadequate forcomparative studies with other species. The morphological variation of the other four species is describedand discussed. Introduction The subgeneric division of the genus Upogebia into the two subgenera, Upogebia (Upogebia)Leach and Upogebia (Calliadne) Strahl, as proposed by de Man (1928) is not used in the presentwork. De Man assigned the species with a spine on the antero-lateral margin of the carapace,and in which the fixed finger (propodal prolongation) of the cheliped is much shorter than thedactylus to the subgenus Upogebia, while he placed species in which the antero-lateral carapacespine is absent and in which the cheliped fixed finger is as long as the dactylus into the subgenusCalliadne. Although many species of Upogebia can be easily assigned to one or the other subgenuson these above-mentioned features, a few show considerable variation in these respects, for ex-ample, in the present study some specimens of Upogebia brasiliensis and Upogebia spinigeracannot be satisfactorily placed in either subgenus. It has been suggested by Bozic and de SaintLaurent (1972) that before subgeneric partitioning of Upogebia can be reconsidered, it will benecessary to examine critically many additional characters, such as branchial formula, mouthappendages, epipods, pereiopods, etc. The measurements given are carapace lengths (c.l.) measured from the rostral apex to thecarapace posterior margin in the mid-line, and the total lengths (t.l.) measured from the rostralapex to the telson posterior margin. Upogebia africana Ortmann (Figs la-h, 2a-l) Upogebia africana, Ortmann, 1894 : 22, pi. 2, fig. 4a, b; Upogebia capensis Stebbing, 1900 : 45; Stebbing,1910 : 370; Upogebia africana de Man, 1928 : 37, 51 ; Upogebia africana Barnard, 1947 : 380; Barnard,1950 : 519, 520. MATERIAL EXAMINED. Port Elizabeth, S. Africa, 1891, 2$& c.l. 20mm, t.l. 57mm; 2?$, c.l. 20 mm, 21 mm, t.l. 60 mm, 62 mm. Port Alfred, S. Africa, 1905, 1 & c.l. 23 mm, t.l. 63 mm. * Present address : Department of Zoology, British Museum (Natural History), Cromwell Road, London, SW7 5BD. Bull. Br. Mus. nat. Hist. (Zool.) 35 (2): 127-200 Issued 26 April, 1979 147 148 NGUYEN NGOC-HO Fig. 1 Upogebia africana Ortmann, <$, 63 mm t.l., Port Alfred : (a) rostrum, dorsal view; (b) rostrum,lateral view; (c) sixth abdominal segment, telson and uropods; (d) maxillule; (e) maxilla; (f)mandible; (g) antennule; (h) antenna. Scale: 2 mm. TAXONOMY OF UPOGEBIA 149 Fig. 2 (a)-(j) Upogebia africana Ortmann, <S, 63 mm t.L, Port Alfred: (a) second maxilliped; (b)first maxilliped; (c) third maxilliped; (d) cheliped, outer lateral view; (e) cheliped, inner lateralview; (f) second pereiopod; (g) third pereiopod; (h) fourth pereiopod; (i) fifth pereiopod; (j) pro-podus and dactylus of fifth pereiopod enlarged, (k), (1) Upogebia capensis (Krauss), ?, 72 mm t.L,South Africa: cheliped, outer lateral view and inner lateral view respectively. Scale: 2 mm. 1 50 NGUYEN NGOC-HO DESCRIPTION. Carapace broad posteriorly, narrowing anteriorly. Front tridentate (Fig. la, b).Rostrum long and conical, setose, projecting far beyond eyes, lower margin unarmed, lateralmargins each with five or six acute teeth. Lateral ridges of gastric region with 11-14 teeth, lateralgrooves large and divergent posteriorly, a smooth, non-setose medio-dorsal groove anteriorly.Anterior part of gastric region between gastric ridges spinose and setose, posterior quarter un-armed and glabrous. Linea thalassinica distinct. Cervical groove deep, lateral part of cervical groovebelow linea thalassinica provided with small denticles in two < out of the five specimens.Telson (Fig. Ic) broader than long, lateral margins slightly convergent distally, postero-lateralangles rounded, posterior margin straight, median groove distinct, median and lateral carinaepresent but not conspicuous. Antennule (Fig. Ig) first peduncular segment unarmed, second segment shortest, third segmentslender, longer than first and second segments together, flagella simple.Antenna (Fig. Ih) scaphocerite terminating in a spine, flagellum long and simple.Mandible (Fig. If) with an inner lateral tooth, small teeth on cutting edge and a larger onebasally. Maxillule (Fig. Id), maxilla (Fig. le) with normal shape as usually observed in Upogebia.First maxilliped (Fig. 2b), second maxilliped (Fig. 2a) and third maxilliped (Fig. 2c) each with asmall epipod. Cheliped(Fig. 2d, e) slightly stouter in the male than in the female. Coxa unarmed. Ischium with1-3 spines on lower margin. Merus with upper margin convex, with two rows of denticles on innerand outer lower margins and 5-7 large teeth proximally. Carpus with one acute spine on distalupper margin followed by a row of 5-7 denticles and another spine on lower margin ; outersurface with a longitudinal groove and a smooth ridge ending in a spine, inner surface with 2-3small denticles on distal margin between the upper and lower spines. Palm with two spinoseridges on upper margin, lower margin of outer surface spinulose proximally, with 1-4 largerspines near the base of fixed finger and another large spine near the base of dactylus; inner surfaceof palm spinulose distally with one or two spines near the base of fixed finger and two additionalspines near the base of dactylus; fixed finger with two denticles on cutting edge in one femalespecimen, smooth in others. Dactylus with two spinose ridges on upper margin, cutting edgedenticulate with two larger teeth near the base, inner surface with a row of 4-5 granules abovecutting edge. In the female, the palm and dactylus of cheliped are less spinose than in the male.Only one spinose ridge is conspicuous on upper margin of the palm, spines and spinules are fewerand smaller on both palm and dactylus. Second pereiopod (Fig. 2f) setose, carpus with a spine on both upper and lower distal margins,other segments unarmed. Third pereiopod (Fig. 2g) merus with 2-4 spines on lower margin; dactylus elongated, slender,lower margin finely pectinate. Fourth pereiopod (Fig. 2h) all segments unarmed, dactylus slender with lower margin pectinate.Fifth pereiopod (Fig. 2i) slender, unarmed and subcheliform; propodus setose with a very smallventro-dorsal process ; dactylus small, lower margin pectinate.Pleopod 1 of the female slender, two-segmented. Pleopods 2-5 large in both sexes; endopod ovate, exopod larger, elliptical with two blunt carinaeon dorsal surface. Uropod (Fig. Ic) broad, as long as telson; protopod with a spine near the base of endopod;endopod triangular with two longitudinal carinae, exopod rounded with three carinae and a spineon the basal part, posterior margins of both endopod and exopod nearly straight, with manyminute spinules. REMARKS. Balss (1913) and de Man (1927, 1928) considered U. africana Ortmann and U. capensis(Krauss) as identical species, but Barnard (1950) stated that the two forms appeared to be localizedone in the colder water, the other in the warmer water and should be kept separate. The present specimens have been compared with some material identified as U. capensis anddeposited in the collections of the British Museum (Natural History). These include 2 $$ from theNatal Coast, 13 mm, 14mm c.l. and 38 mm, 40mm t.l. and 1 ? from offshore South Africa,25 mm c.l., 72 mm t.l. The similarities and differences observed are listed in Table 1. TAXONOMY OF UPOGEBIA 151 Table 1 Comparison of U. africana from Port Alfred and Port Elizabeth with U. capensis from NatalCoast and South Africa U. africana U. capensis From Port Alfred From Natal and Port Elizabeth Coast From S Africa Denticles on hind margin of cervical groove present in 2 out of present, small present, spiniform 5 specimens The decisive diagnostic character separating the two species (Barnard, 1950) is the presence ofcoxal spines on legs 1-3 in U. capensis and their absence in U. africana. In this respect, the materialfrom Natal Coast must be reidentified as U. africana while the specimen from South Africa is atrue U. capensis. Its cheliped is illustrated in Fig. 2k, 1. In addition to the absence of coxal spines on legs 1-3, the material of U. africana from NatalCoast and that from Port Alfred and Port Elizabeth all have 1-4 large spines on the lower outermargin of the palm of the cheliped, near the fixed finger and all without a spine on the upper distalmargin of the merus of the second pereiopod. The material of U. africana from Port Alfred and Port Elizabeth has no spine on the upperdistal margin of the merus of the cheliped, but this spine is present in the specimens of U. africanafrom Natal Coast as well as in that of U. capensis from South Africa. It would appear that thisvariable feature cannot be used in separating the two forms.* DISTRIBUTION. Port Elizabeth (Ortmann, 1894); Zwartkops River estuary, Algoa Bay (Stebbing,1900); Gordon's Bay, east side of False Bay (Stebbing, 1910); Somerset Strand and Gordon'sBay, estuary of Breede River (Port Beaufort), Knysna lagoon, Keurbooms river estuary (Pletten-berg Bay), Zwartkops estuary, Nahoon river estuary (East London), Port St Johns and DurbanBay (Barnard, 1950); Natal Coast, Port Alfred. Upogebia brasiliensis Holthuis(Fig. 3a, b) Upogebia brasiliensis Holthuis, 1956: 175-181, figs 1,2; Upogebia brasiliensis Gomes Correa, 1968: 97-109. MATERIAL EXAMINED. Georgetown, British Guiana, 1917, 2 3$, c.l. 7mm, t.l. 21 mm, 22mm;3 ??, c.l. 6-8 mm, t.l. 19-24 mm. * After the completion of this paper the author had the opportunity to examine some material of U. capensisfrom S.W. Africa (Zool. Mus. Berlin 16130) which was on loan by the Berlin Museum to Dr K. Sakai. The materialincluded 55 specimens of 16-70 mm t.l. in which the following features were observed: 1. The antenna, both peduncle and flagellum, is more slender than that of U. africana. 2. Coxal spines are present on lst-3rd pereiopods in all specimens, that of 3rd pereiopod usually small. 3. Outer surface of cheliped palm with small spinules only but without any large spines. 4. Merus of 2nd pereiopod with one spine on upper distal margin, except in two specimens.The above observations confirm Barnard's view of separating U. africana and U. capensis. 152 NGUYEN NGOC-HO Fig. 3 Cheliped, outer lateral view and inner lateral view respectively: (a), (b) Upogebia brasiliensisHolthuis, <?, 22mm t.l., Georgetown; (c), (d) Upogebia carinicauda (Stimpson), ?, 39 mm, t.l.,Gulf of Siam; (e), (Q Upogebia issaeffi (Balss), ?, 41 mm t.l., Tsur Island; (g), (h) Upogebiaspinigera (Smith), ?, 26 mm t.l., West Coast of Central America. Scale: 2 mm. TAXONOMY OF UPOGEBIA 153 REMARKS. All specimens agree with the description of the species and with one of the type speci-mens examined (ovigerous $, 29 mm t.l.) except in the following features : 1 . The spine on the antero-lateral margin of the carapace is absent in the female from Ecuador. 2. The large subterminal tooth on the cutting edge of the cheliped dactylus is absent in thethree females from Georgetown. 3. The cheliped carpus of the male bears a row of six small denticles on its dorsal side, behindthe anterior dorsal spine, and on the outer side, another large spine on its anterior margin,between the dorsal and ventral ones. 4. Spines on the lower margin of the cheliped merus are very small in the female from Ecuador. 5. The lower margin of the merus of the third pereiopod is unarmed in one female specimenfrom Georgetown. DISTRIBUTION. Brazil (Holthuis, 1956; Gomes Correa, 1968); Georgetown, British Guiana;Esmeraldas, Ecuador. Upogebia carinicauda (Stimpson)(Fig. 3c, d) Gebia carinicauda Stimpson, 1860:23; Gebia barbata Strahl, 1861 : 1062, figs 7-9; Gebia carinicaudaMiers, 1884 : 280; Gebia carinicauda de Man, 1888 : 256; Gebia barbata Ortmann, 1892 : 54, fig. 8;Gebia barbata Ortmann, 1894 : 22; Upogebia (Upogebia) carinicauda de Man, 1926 : 341-345; de Man,1928 : 60-65, figs 6, 6a-n; Upogebia (Upogebia) kempi Shenoy, 1967 : 777-804, figs 1-12; Upogebia(Upogebia) kempi Sankolli, 1972 : 671-682, figs 9, 10. MATERIAL EXAMINED. Gulf of Siam, 1898, 1 ?, c.l. 13 mm, t.l. 39 mm. REMARKS. The present specimen is compared with material of U. carinicauda in the BM(NH)with three specimens of U. carinicauda of the Siboga Expedition and with two paratype specimensof U. kempi Shenoy from Bombay. Material of U. carinicauda 1. Thursday Island, $ (BM(NH) Reg. No. 81-31) c.l. 7 mm, t.l. 20 mm 2. Thursday Island, <$ (BM(NH) Reg. No. 82-7) c.l. 10mm, t.l. 30mm 3. Thursday Island, $ (BM(NH) Reg. No. 82-7) c.l. 12 mm, t.l. 35 mm 4. Island of Torres Straits, $ (BM(NH) Reg. No. 77-12) c.l. 11 mm, t.l. 33 mm 5. Ambon, Siboga Exped. St. 181, $, c.l. 6 mm, t.l. 21 mm 6. Ambon, Siboga Exped. St. 181, <$, c.l. 7 mm, t.l. 23 mm 7. Ambon, Siboga Exped. St. 181, $, c.l. 10mm, t.l. 32mm Material of U. kempi, two paratypes 8. Bombay, $, c.l. 14 mm, t.l. 45 mm 9. Bombay, ovigerous $, c.l. 14 mm, t.l. 46 mm Table 2 lists the main similarities and differences observed. The present material from the Gulf of Siam agrees very well with specimens of U. carinicaudaidentified by Miers (1 884) and also with two specimens of the material from Ambon and is identicalto the type specimens of U. kempi. With the exception of the female specimen from Ambon of21 mm t.l., all specimens considered in Table 2 are similar in having: (a) four spines on the ros-trum; (b) an antero-lateral carapace spine; (c) a spine on the upper distal margin of the chelipedmerus ; (d) three large spines on the inner anterior margin of the cheliped carpus ; (e) a largespine on the lower margin of the palm near the fixed finger; and (/) a spine on the upper distalmargin of the merus of the second pereiopod. The following variations are observed: 1. The rostrum is short in most specimens of total length less than 33 mm. In larger specimensof U. carinicauda and U. kempi, the rostrum reaches well beyond the eye-stalks. 2. The ovigerous paratype of U. kempi has a fairly large tubercle on the antero-lateral marginof the carapace, near the base of the antenna whilst in the other female, a few very small tuberclesare present. They are absent in all specimens of U. carinicauda. 154 NGUYEN NGOC-HO Table 2 Specimens of U. carinicauda and U. kempi compared, from various Indo-Pacific localities 3. Denticles behind the dorsal spine of the cheliped carpus are absent in all specimens fromAmbon. In others, they show variation in size which seems to be related to the size of the animals. 4. Denticles on the upper margin of the cheliped palm are absent in one specimen of U.carinicauda from Thursday Island and in all specimens from Ambon. When they are present, itwould seem that these denticles appear first on the distal part of the palm and then on the proximalpart as the animals mature. They are large and apparent in the specimen from the Gulf of Siamand in the paratypes of U. kempi. TAXONOMY OF UPOGEBIA 155 5. In small specimens, the telson is wider proximally than distally. In larger specimens, itapproximates a rectangular shape. 6. Although having four spines on the rostrum, the female specimen from Ambon of 21 mm t.l.is devoid of nearly all other specific characters of U. carinicauda and the fixed finger of its chelipedis as long as the dactylus. It is probably an immature specimen, nevertheless its identification asU. carinicauda seems to be very uncertain. DISTRIBUTION. Hongkong (Stimpson, 1860). Luzon (Strahl, 1861). Thursday Island, TorresStraits (Miers, 1884). Elphinstone Island, Mergui Archipelago (de Man, 1888), Samoa Island(Ortmann, 1892). Amboina (Ortmann, 1894; de Man, 1928). Buka, Salomon Islands (de Man,1926). Anchorage of Labuan Pandan, Lombok; Anchorage off Seba, Savu; Haingsisi, SamauIsland, Timor; Taruna-bay, Great-Sangir Island; Dammer; Saleyer-anchorage (de Man, 1928).Bombay, India (Shenoy, 1967; Sankolli, 1972). Gulf of Siam. Upogebia darwini (Miers) Gebiopsis Darwinii Miers, 1884:281, pi. 32, fig. A; Gebiopsis intermedia de Man, 1888 : 256, pi. 16,figs 6-8; Gebiopsis Darwinii Henderson, 1893 : 432; Gebia (Gebiopsis) intermedia Ortmann, 1894 : 23;Gebiopsis intermedia Zehntner, 1894:194; Gebiopsis intermedia Lanchester, 1901:555; Upogebiaintermedia Pearson, 1905 : 91; Upogebia (Calliadne) Darwinii Nobili, 1906 : 97; Upogebia (Calliadne')Darwinii Borradaile, 1910: 262; Upogebia (Calliadne) Darwinii de Man, 1928 : 24, 50, 84-86, figs 12,12a-f; Upogebia darwini Ngoc-Ho, 1977:439-464, figs 1-13. MATERIAL EXAMINED. Singapore, 1899, 1 & c.l. 12 mm, t.l. 34 mm; 2 ovigerous ??, c.l. 11 mm and11-5 mm, t.l. 31 mm and 34 mm. REMARKS. The present material agrees with the types of the species with which it has been com-pared except for some variations in the spinulation of the merus cheliped lower margin. Similarlyto the types, the smaller female has 9-10 spines on the merus cheliped lower margin, whilst themale has 19-20 spines and the larger female has up to 28-30 spines on this margin. In the male,those spines are large proximally and decrease in size distally; in both females, they are small. DISTRIBUTION. Port Darwin (Miers, 1884); Singapore (Miers, 1884, present paper); ElphinstoneIsland, Mergui Archipelago (de Man, 1888); Rameswaram, Tutticorin, Cheval Par (Henderson,1893); Amboina (Ortmann 1894, Zehntner 1894, de Man 1928); Pulu Bidan, Penang (Lanchester,1901); South of Adam's Bridge and Muttuvaratu Paar (Pearson, 1905); Aden, Perim, Obock(Nobili, 1906); Saya de Malha Bank (Borradaile, 1910); Phuket, Thailand (Ngoc-Ho, 1977). Upogebia issaeffi (Balss)(Fig. 3e, f; Fig. 4a-i; Fig. 5a-h) Gebia (Upogebia) issaeffi Balss, 1913 : 239; Balss, 1914 : 89-90, figs 48-49; Upogebia (Upogebia) Issaeffide Man 1927 : 27-29; de Man 1928 : 39, 41; Upogebia issaeffi Makarov, 1938 : 59-61, figs 19, 20;Upogebia Issaeffi Yokoya, 1939 : 278; non Upogebia (Upogebia) issaeffi Sakai, 1968 : 47, fig. ID. MATERIAL EXAMINED. Tsur Island (Tsuru Shima or Tsuri Shima, Japan ?), 1892, 7 $<$, c.l.11-5-19-5 mm, t.l. 36-58 mm; 3 $?, c.l. 12-19 mm, t.l. 37-60 mm. DESCRIPTION. Carapace broad posteriorly, narrowing anteriorly. Front tridentate. Rostrum (Fig. 4a, b) triangular, setose, projecting far beyond eyes, lowermargin unarmed, lateral margins each with four or five acute teeth. Lateral ridges of gastricregion with 10-11 teeth, lateral grooves large and slightly divergent posteriorly. Anterior part ofgastric region between gastric ridges spinose and setose; middle line and about 1/5 of posteriorpart of gastric region unarmed and glabrous. Lima thalassinica distinct. Cervical groove deep,lateral part below linea thalassinica with a few small spinules. Spine on antero-lateral margin ofcarapace distinct, it is bifid in two specimens. 156 NGUYEN NGOC-HO Fig. 4 Upogebia issaeffi (Balss), <J, 51 mm t.L, Tsur Island: (a) rostrum, dorsal view; (b) rostrum,lateral view; (c) antennule; (d) antenna; (e) mandible; (f) second maxilliped; (g) first maxilliped;(h) maxillule; (i) maxilla. Scale: 2 mm. Telson (Fig. 5h) about as long as sixth abdominal segment and slightly broader than long. Lateral margins a little convergent, postero-lateral angles rounded, posterior margin straight or slightly concave in the middle, median groove distinct but median and lateral carinae uncon- spicuous. Antennule (Fig. 4c) first and second peduncular segments of equal length, third segment longer than first and second segments together. Flagella simple. Antenna (Fig. 4d) second peduncular segment with a spine near distal end of lower margin, scaphocerite rounded without spine, flagellum long. TAXONOMY OF UPOGEBIA 157 Fig. 5 Upogebia issaeffi (Balss), <?, 51 mm t.l., Tsur Island: (a) third maxilliped; (b) second pereio-pod; (e) third pereiopod; (d) fourth pereiopod; (c) fifth pereiopod; (f) cheliped, outer lateral view;(g) cheliped, inner lateral view; (h) telson and uropods. Scale: 2 mm. 1 58 NGUYEN NGOC-HO Mandible (Fig. 4e) with small teeth on cutting edge and a larger one basally.Maxillule (Fig. 4h), maxilla (Fig. 4i) apparently showing no differences with those of otherUpogebia species. First maxilliped (Fig. 4g) with a fairly large and rounded epipod.Second maxilliped (Fig. 4f), third maxilliped (Fig. 5a) each with a small epipod.Cheliped (Fig. 3e, f ; Fig. 5f, g). Ischium with one spine near distal end of lower margin. Meruswith one spine near distal end of upper margin, lower margin with a few small tubercles distallyand 3-6 acute spines proximally. Upper margin of carpus with a row of 9-10 small tubercles anda large spine at distal end, on the outside of which 2-5 other small spines are present; a spinenear distal end of lower margin of carpus and on the inner side, a third spine on distal margin,about halfway between the upper and the lower ones. Upper margin of propodus with a longitu-dinal ridge provided with small tubercles proximally and distally with 5-7 larger spines, the distalone large and acute; lower margin with two or three blunt spines proximally, with a large, sharpspine and a few tubercles near the base of fixed finger and another rounded spine near the base ofdactylus ; fixed finger with a large conical tooth. Dactylus setose, upper margin, in male (Fig. 5f, g),with a longitudinal crest bearing on its outer side a row of fine transverse striae; two longitudinalrows of granules on the outer side of dactylus, a row of granules and another row of obliqueridges on the inner side ; cutting edge with two obtuse teeth more or less fused together. Dactylusof cheliped of female (Fig. 3e, f ) without row of transverse striae on upper margin but with a rowof rounded granules ; two additional similar rows of granules present, one on the outer side, theother on inner side of dactylus ; oblique ridges also present on inner side but much less con-spicuous than in the male. Second pereiopod (Fig. 5b). Merus with one spine near distal end of upper margin and two spinesproximally on lower margin; carpus with one spine on distal end of both upper and lower margin;propodus and dactylus very setose but unarmed. Third pereiopod (Fig. 5e). Merus with three acute teeth and a few small tubercles on lower margin;carpus and propodus setose, flattened and unarmed; dactylus slender, lower margin finelypectinate. Fourth pereiopod (Fig. 5d). All segments unarmed, carpus and propodus very setose, lower marginof dactylus finely pectinate. Fifth pereiopod (Fig. 5c). Propodus slender and setose with a small ventro-distal process; dactylusshort. First pleopod, in female, with two elongated segments. Second to fifth pleopods large in both sexes; endopod rounded, exopod larger, elliptical.Uropod (Fig. 5h) broad, as long as telson; protopod with a small spine on inner side; endopodtriangular, exopod ovate, each with two longitudinal carinae. REMARKS. Balss (1913) and de Man (1927) considered the stridulating ridge on the dactylus of thecheliped an important feature for separating U. issaeffi from other species. However, both authorshad probably examined male specimens in which this ridge is clearly present. Makarov (1938) studying material from Vladivostok observed a sexual difference in the pre-sence or absence of a stridulating ridge on,the dactylus of the cheliped, but Sakai (1968) found nosuch difference in his material of U. issaeffi from Japan. Sakai later considered the identificationof his material as incorrect (personal communication). The present material confirms Makarov's view, the stridulating ridge is here present only in themale. As it is absent in the female, this feature can no longer be used as a distinguishing characterof the species. DISTRIBUTION. Vladivostok (Balss, 1913; Makarov, 1938); Onagawa, Miyagi Pref. (Yokoya,1939); Tsur Island. Upogebia spinigera (Smith)(Fig. 3g, h) (Fig. 3g, h) Gebia spinigera Smith, 1871 : 92-93; Gebia longipollex Streets, 1871 : 242; Gebia longipollex Lockington,1877 : 108; Lockington, 1878 : 300; Gebia spinigera Lockington, 1878 : 300; Gebia spinigera Pocock, TAXONOMY OF UPOGEBIA 159 1890:515; Upogebia (Upogebia) longipollex Borradaile, 1903:543; Upogebia (Upogebid) spinigeraBorradaile, 1903:543; Upogebia (Upogebid) longipollex de Man, 1928:23, 35, 39, 51; Upogebia(Upogebid) spinigera de Man, 1928:29, 39, 45; Upogebia (Upogebid) sturgisae Boone, 1931 : 161,fig. 11; Upogebia spinigera Holthuis, 1952 : 1-11, figs 1, 2. MATERIAL EXAMINED. Rio Tumbler (Rio Tumbes, Peru ?), 1890, 3 <&J, c.l. 10-12 mm,t.l. 31-36 mm; 6 $$ (5 ovigerous), c.l. 9-12 mm, t.l. 29-40 mm. St Lucia, Peru, 1890, 1 & c.l. 11 mm, t.l. 36 mm. West Coast of Central America, 1875, 1 & c.l. 10 mm, t.l. 31 mm; 2 $? (1 ovigerous), c.l. 8 mm, 10 mm, t.l. 26 mm, 30 mm. Esmeraldas, Ecuador, 1925, 2<J<J, c.l. 8mm, 10mm, t.l. 25mm, 31 mm; 2$$ (1 ovigerous), c.l. 10 mm, 12 mm, t.l. 33 mm, 42 mm. REMARKS. The present material has been compared with the two specimens of U. spinigeradescribed by Holthuis (1952). Table 3 lists the main variations observed. Table 3 Variations in the material of U. spinigera from areas of Central and South America Material from W. coast of Material from Material from Central Material from Material from Esmeraldas, Colombia America St Lucia, Peru Rio Tumbler Ecuador Number of specimensexamined Spines on hind marginof cervical grooveSpines on anteriormargin of carpus ofpereiopod 2Spines on uppermargin of carpus andmerus of pereiopod2 and 4 Spines on lowermargin of merus ofpereiopod 3Spines on lowermargin of merus ofpereiopod 4Coxal spines onpereiopods 1-3 present, largepresent, large present, small and transparent present presentpresent 3 1 present, large present, small present in present, small2 specimens absent present absent present present in absent2 specimens present onpereiopods2 and 3 absent present, small present in 2 specimenspresent in present4 specimens absent present absent absent present absent present on presentpereiopod 3 1 . Spines on the lateral part of the cervical groove, which are apparent in the material fromColombia, are much smaller in the present material and are missing in two specimens (1 <$, 1 $)from Ecuador. 2. The subterminal spine of the cheliped dactylus is large in the present material and usuallylarger than that of the specimens from Colombia. In some specimens, the cheliped fixed fingeris nearly as long as the dactylus. The cheliped of the material from Colombia was illustrated byHolthuis (1952) and that figure seems to represent the inner side of the appendage. The descriptionof the outer side of the cheliped would correspond in fact to the inner side and vice versa. Theinner and outer side of the left cheliped of the ovigerous female from the West Coast of CentralAmerica are here illustrated (Fig. 3g, h). 160 NGUYEN NGOC-HO 3. Both the upper and the lower margin of the carpus of the second pereiopod bear a spinedistally. These two spines are large in the Colombia specimens but small or absent in the presentmaterial. 4. Small and transparent spines are present on the upper margin of the carpus and merus of thethird and fourth pereiopods of the Colombia specimens but are absent in the present material.They are not mentioned either in the original description of the species by Smith (1871) and Hol-thuis (1952) thought they were overlooked by the former author. Since none of the present speci-mens has got these spines, they may in fact be absent in Smith's material also. 5. Smith (1871), Boone (1931) and Holthuis (1952) mention that the lower margin of the thirdand fourth pereiopods is armed with spines whilst Streets (1871) states that these segments areunarmed. In the present material, the lower margin of the merus of the third pereiopod is armedin all specimens but in most of them, the same margin of the fourth pereiopod is unarmed. 6. The presence of coxal spines on the lst-3rd pereiopod is subject to variation among speci-mens of the present material. Coxal spines are absent from the fourth pereiopod and are presenton the fifth pereiopod in all specimens of the present material as well as that from Colombia. DISTRIBUTION. Gulf of Fonseca, N.W. Nicaragua; Aseredoras Island, W. Nicaragua (Smith,1871). Isthmus of Panama (Streets, 1871). Fernando Noronha, N.E. Brazil (Pocock, 1890).Patillo Point, Panama (Boone, 1931). Colombia (Holthuis, 1952). Rio Tumbler; St Lucia, Peru;Esmeraldas, Ecuador. Acknowledgements I wish to thank the Trustees of the British Museum (Natural History) for allowing me the oppor-tunity to examine their collections and for the working facilities provided, Dr R. W. Ingle forkindly supervising my research and for critically reading the manuscript. I also wish to thank theDirectors of the Rijksmuseum van Natuurlijke Historic, Leiden; Instituut voor TaxonomischeZoologie, Amsterdam; Naturhistoriska Riksmuseet, Stockholm; and the Zoological Survey ofIndia, Calcutta for sending material for examination; Mme M. de Saint Laurent, Museumnational d'Histoire naturelle, Paris for her advice, and Danida (Danish International Develop-ment Agency) for the financial support received during part of the work. References Balss, H. 1913. Diagnosen neuer ostasiatischer Macruren. ZooL Anz. Leipzig 42 (5) : 234-239. 1914. Ostasiatische Decapoden H Die Natantia und Reptantia. Munchen Abh. Bayer Akad. Wiss. II Suppl. Bd 10 : 4-101.Barnard, K. H. 1947. Descriptions of new species of South African Decapod Crustacea with notes on synonymy and new records. Ann. mag. not. Hist. (11) 13, 1946 : 361-392.1950. Descriptive catalogue of South African Decapod Crustacea (crabs and shrimps). Ann. S. Afr. Mus. 38 : 1-837.Boone, L. 1931. A collection of Anomuran and Macruran Crustacea from the Bay of Panama and fresh waters of the Canal Zone. Bull. Amer. Mus. nat. Hist. 63 : 137-189. Borradaile, L. A. 1903. On the classification of the Thalassinidea. Ann. Mag. nat. Hist. 1 (12) : 531-551.1910. The Percy Sladen Trust Expedition to the Indian Ocean in 1905. Vol. II, no. X. Penaeidea, Stenopidea, and Reptantia from the Western Indian Ocean. Trans. Linn. Soc. Land. (Zool.) 13 : 257-264.Bozic, B. & de Saint Laurent, M. 1972. Description et position systematique d'Upogebia contigua sp. nov. du Golfe de Guin6e (Crustacea Decapoda Callianassidae). Bull. Mus. Hist. nat. Paris 3e sen 35 (Zool. 29) : 339-346.Gomes Correa, M. M. 1968. On the species of Upogebia of the littoral of Brazil, with the description of a new species (Decapoda, Callianassidae) Revta bras. Biol. 28 : 97-109. Henderson, J. R. 1893. A contribution to Indian carcinilogy. Trans. Linn. Soc. Lond. (Zool.) 5 : 325-458.Holthuis, L. B. 1952. Reports of the Lund University Chile Expedition 1948-49. 4. On two species of Crustacea Decapoda from the N.W. coast of South America. Lund. Univ. Arsskrift N.F. Avd. 2. 47 (9) : 1-11. TAXONOMY OF UPOGEBIA 161 1956. Three species of Crustacea Decapoda Macrura from Southern Brazil, including a new species of Upogebia. Zool. Meded. Leiden 34 (11) : 173-187.Lanchester, W. F. 1901. On the Crustacea collected during the 'Skeat' Expedition to the Malay Peninsula together with a note on the genus Actaeopsis. Proc. Zool. Soc. Lond. 1901 : 533-574.Lockington, W. N. 1877. Remarks on the Crustacea of the West Coast of North America, with a catalogue of the species in the Museum of the California Academy of Sciences. Proc. Calif. Acad. Sci. 7 : 94-108.1878. Remarks upon the Thalassinidea and Astacidea of the Pacific Coast of North America, with description of a new species. Ann. Mag. nat. Hist. 5 (2) : 299-304.Makarov, V. V. 1938. Crustacea. Fauna of U.S.S.R. 10 (3) : 54-61.de Man, J. G. 1888. Report on the Podophthalmous Crustacea of the Mergui Archipelago, collected for the Trustees of the Indian Museum, Calcutta, by Dr John Anderson. J. Linn. Soc. Lond. 22 : 1-312.1926. Beschreibung zweier Arten von Decapoda Macrura von der Insel Buka (Salomoninseln). Mitt. Zool. Mus. Berl. 12 (2) : 341-345.1927. A contribution to the knowledge of twenty-one species of the genus Upogebia Leach. Capita zoologica 2 (5) : 1-58. 1928. The Decapoda of the Siboga Expedition. VII. The Thalassinidae and Callianassidae collected by the Siboga Expedition with some remarks on the Laomediidae. Siboga Exped. Monogr. 39a6 : 1-187.Miers, E. J. 1884. Report on the zoological collections made in the Indo-Pacific Ocean during the voyage of H.M.S. 'Alert' 1881-1882. London : 178-322.Ngoc-Ho, N. 1977. The larval development of Upogebia darwini (Crustacea, Thalassinidea, Upogebiidae) reared in the laboratory, with a redescription of the adult. /. Zool. Lond. 181 : 439-464.Nobili, G. 1906. Faune cacinologique de la Mer Rouge. Decapodes et Stomatopodes. Annls Sci. nat. Paris IXe ser. (Zool.) 4 : 1-347.Ortmann, A. 1892. Die Decapoden. Krebse des Strasburger Museums. Zool. Jb. Jena. 6 (1) : 1-58. 1894. Crustaceen. In: Richard Semon zoologische Forchungreisen in Australien und dem Malayis- chen Archipel. Denkschr. med.-naturw. Ges. Jena 8 : 1-80.Pearson, J. 1905. Report on the Macrura collected by Professor Herdman, at Ceylon, in 1902. Rep. Pearl Oyster Fish. 5 (Supp. Rep. 24) : 65-92.Pocock, R. I. 1890. Crustacea. In: Ridley, H. N., Notes on the zoology of Fernando Noronha. /. Linn. Soc. Lond. Zool. 20 : 506-526.Sakai, K. 1968. Three species of the genus Upogebia (Decapoda, Crustacea) in Japan. /. Seika worn. junior Coll. I : 45-50.Sankolli, K. N. 1972. The Thalassinoidea (Crustacea, Anomura) of Maharashtra. /. Bombay nat. Hist. Soc. 68 (3) : 671-682.Shenoy, S. 1967. Studies on larval development in Anomura (Crustacea, Decapoda) 2: Proc. Symposium on Crustacea, Ernakulam, 1965. Mar. Biol Assoc. India Symp. Ser. 2 : 777-804.Smith, S. 1. 1871. List of the Crustacea collected by J. A. McNiel in Central America. Rep. Peabody Acad. Sci. 2 & 3 : 87-98.Stebbing, T. R. R. 1900. South African Crustacea, Cape of Good Hope. Mar. Invest. S. Afr. : 1-66. 1910. General catalogue of South African Crustacea. Mar. Invest. S. Afr. : 281-593. Stimpson, W. 1860. Prodromus descriptionis animalium evertebratorum, quae in Expeditione ad OceanumPacificum Septentrionalem, a Republica Federata missa, Cadwaladaro Ringgold et Johanne RodgersDecibus, observavit et descripsit. Proc. Acad. nat. Sci. Phila. : 22-47. Strahl, 1861. Hr. W. Peters legte eine Abhandlung des Hrn. Dr. Strahl vor: iiber einige neue von Hrn. F.Jagor eingesandte Thalassinen und die systematische Stellung dieser Familie. Mber. K. preuss. Akad.Wiss. : 1055-1072.Streets, T. H. 1871. Catalogue of Crustacea from the Isthmus of Panama collected by J. A. McNeil. Proc. Acad. nat. Sci. Phila. 1871 : 238-243.Yokoya, Y. 1939. Macrura and Anomura of Decapod Crustacea found in the neighbourhood of Onagawa, Miyagi-ken. Sci. Rep. Tohoku Imp. Univ. Ser. 4, 14 (2-3) : 287.Zehntner, L. 1894. Crustaces de 1'Archipel malais. Revue suisse Zool. 2 (1) : 135-214. Manuscript accepted for publication 9 June, 1977 Larval development of British prawns and shrimps(Crustacea : Decapoda : Natantia). 2. Palaemonetes(Palaemonetes) varians (Leach, 1814) andmorphological variation A. A. Fincham Department of Zoology, British Museum (Natural History), Cromwell Road, London SW7 5BD Synopsis Five larval and selected post larval stages of Palaemonetes (Palaemonetes) varians are described fromspecimens reared in the laboratory. The rate of larval development and the effect of desynchronizationof epigenesis and moulting are discussed. Analysis of morphometric and meristic variation showed thatnormalizing selection may result in a reduction in variation of larval size distribution at metamorphosis.No such reduction in variation of meristic characters was found. A significant increase in variation of theexopodite of the mouthpart maxilla 2 was recorded from the closely related palaemonid Palaemon(Palaeander) elegans. The significance of these results is discussed with reference to the life histories ofthese shrimps. Introduction Palaemonetes (Palaemonetes) varians or the ditch shrimp has been the subject of larval develop-ment studies for nearly 140 years (see synopsis of larval data, below). The species is reared easilyin the laboratory and this explains, to some extent, its popularity. It was cited as an example ofpoecilogony (Boas, 1889) or larval polymorphism, until Sollaud (19230) showed that there were,in fact, different species in northern and southern Europe and in North Africa but that co-existenceoccurred. Heldt (1953) revived the controversy after examining samples of P. (P.) varians fromLake Kelbia in Tunis. In different salinities Heldt reported that '. . . ces larves differentes, issuesde ces deux sortes d'ceufs, aboutissent ... a des adultes morphologiquement identiques'. It is,however, not difficult to see why the concept of poecilogony has been applied to this species whichdoes, apparently, show considerable phenotypic variation during larval development and meta-morphosis. A species is often characterized solely by genotype and phenotype in discussions on develop-ment. Waddington (1953) developed a further concept -the epigenotype which he defined as*. . . the system of causal relations by which the newly fertilized zygote . . . becomes realized asthe fully developed adult'. He distinguished between normalizing selection in which phenotypesresulting directly from the presence of an abnormal gene were removed from a population, andstabilizing selection which involved the removal of phenotypes disadvantaged by an unstableepigenetic system. In this context morphometric and meristic data for larval stages of Palaemonetes (Palaemonetes)varians were pooled and analysed to see if epigenetic development in shrimps followed the samepattern reported recently in the development of newts (Bell, 1974, 1975), when a decrease inmorphological variation was recorded as the animals approached metamorphosis. Materials and methods Rearing Ovigerous Palaemonetes (Palaemonetes) varians (Leach) were collected in July 1976 by handnettingfrom ditches alongside the estuary at Burnham-on-Crouch, Essex, England (grid reference Bull. Br. Mus. nat. Hist. (Zool.) 35 (2): 127-200 Issued 26 April, 1979 163 164 A. A. FINCHAM TQ 943957). Rearing techniques, similar to those reported previously (Fincham, 1977), wereused with the following modifications : 1. The constant temperature room was at 22 0-5 C; 2 C below the temperature of the waterin the ditches where the collections were made. 2. No mass cultures were set up in order to eliminate the problems of identifying later zoealstages where moulting history was not available. To ensure, however, that adequate materialwas available for drawing and assessing morphological variation, eight compartmented trayswere set up, containing 144 larvae. At each zoeal stage, 10 larvae, their moults, and a further10 moults from other individuals, were preserved. 3. All trays and equipment were sterilized with boiling water before use to prevent the accumula-tion of bacteria. Larval material has been deposited in the Crustacea collection of the BM(NH), registrationnumber 1977 : 284. Analysis of morphometric and meristic variation Ten moults and larvae were examined at each stage to determine the range of overall size andalso of setal numbers on selected appendages. Mean (Jc) and standard deviation (s.d.) werecalculated for each character at the different stages. To test if there was a genuine increase in vari-ation other than an increase expected from animals of greater size, coefficients of variation(lOOx s.d./meari) were calculated. Palaemonetes (Palaemonetes) varians (Leach, 1814) Palaemon varians Leach, 1814.Palaemon variabilis Bouchard-Chantereaux, 1829.Palaemonetes varians microgenitor Boas, 1889.Palaemonetes varians occidentalis Sollaud, 1923.Palaemonetes (Palaemonetes) varians Holthuis, 1949. SYNOPSIS OF LARVAL DATA FROM PUBLISHED WORK. Palaemon variabilis: Du Cane, 1839 (zoeae1-4, dorsal, lateral views, plankton, British waters); Palaemonetes varians: Boas, 1880 (selectedappendages of some zoeae, Danish waters); Mayer, 1880 (zoeae 1-4, post larvae, some dorsal,lateral views, appendages, Mediterranean waters); Weldon, 1890 (zoeae 1-3/4, no figures,laboratory reared, British waters); Allen, 1893a, b (development of green gland, shell gland andbody cavity in larvae, laboratory reared, British waters); P. v. microgenitor: Sollaud, 1914 (eggsize, abbreviated development and order of appendage appearance); Sollaud, 1919 (effect ofenvironment on duration of larval life, French waters); Sollaud, 1921 (phototropism before andafter metamorphosis); P. varians: Gurney, 1923 (breeding period, British waters); P. v. occiden-talis: Sollaud, 1923a (zoeae 1-5, post larva, French waters); 1923ft (larval polymorphism);P. varians: Gurney, 1924 (zoeae 1-5, post larvae, plankton and laboratory reared, British waters);Sollaud, 1930 (larval polymorphism); Heldt, 1953 (larval polymorphism); Weygoldt, 1961(embryology, German waters); Le Roux, 1970 (effect of environment on number of larval stages,French waters). In the following short descriptions of the key characters of the larval stages, all setal countshave been omitted but these are recorded in Table 1. DESCRIPTION OF LARVAL STAGES Key characters are printed in italic type. ZOEA 1 (Fig. 1) 3-8 mm (3-5^-1 mm) Head (Figs la, b): eyes sessile. Carapace (Figs la, b): without spines, rostrum straight, tapering distally, ventral margin withminute retrorse teeth distally. LARVAL DEVELOPMENT OF PALAEMONETES VARIANS 165 Fig. 1 Zoea 1 : (a) dorsal view; (b) lateral view; (c) antenna 1 ; (d) antenna 2; (e) mandibles; (f)maxilla 1; (g) maxilla 2; (h) maxilliped 1; (i) maxilliped 2; (j) maxilliped 3; (k) pereiopod 1; (1)pereiopod 2; (m) pereiopod 3; (n) pereiopod 4; (o) pereiopod 5; (p) telson. Bar scales: a, b =0-5 mm; c, d, h-p = 0-2 mm; g = 0-l mm; e, f=0-05 mm. 166 A. A. FINCHAM Antenna 1 (Fig. Ic): peduncle bearing single flagellar segment with three aesthetascs distally,one wider than the others.* Antenna 2 (Fig. Id): exopodite as a broad lamina divided into 5 short segments distally. Mandibles (Fig. le): asymmetrical. Maxillipeds 1-3 (Figs Ih-j): with natatory exopodites. Pereiopods 1-4 (Figs Ik-n): rudimentary, biramous. Pereiopod 5 (Fig. lo): rudimentary, uniramous. Abdomen (Figs la, b): somite 6 continuous with telson; pairs of ventral buds on somites 1-5indicate position of pleopods. Telson (Fig. Ip): fans out distally, posterior margin bears 7 + 7 plumose spines, with minutespines between four innermost pairs of spines. ZOEA 2 (Fig. 2) 4-2 mm (4-0-4-5 mm) Head (Figs 2a, b): eyes 'stalked'. Carapace (Figs 2a, b) : one dorso-medial and a pair of supraorbital spines all bent forward withsmall retrorse teeth ventrally, rostrum without teeth. Antenna 1 (Fig. 2c) : distal segment of peduncle bearing first segment of internal flagellum,external flagellum now with four distal aesthetascs, two wider than others. Pereiopods 1, 2 (Figs 2k, 1): developed, with natatory exopodites. Pereiopods 3, 4 (Figs 2m, n) : rudimentary, biramous. Pereiopod 5 (Fig. 2o) : developed, uniramous (without exopodite). Abdomen (Figs 2a, b): somite 5 with posterior margin produced into a pair of spines. Telson (Fig. 2p): developing uropods visible beneath exoskeleton; in central group of smallspines, one pair longer than the others. ZOEA 3 (Fig. 3) 4-6 mm (4-3-4-8 mm) Carapace (Figs 3a, b) : two dorso-medial spines and a small frontolateral spine at edge of cara-pace beneath the eyes, former with retrorse teeth ventrally. Antenna 1 (Fig. 3c) : external flagellum with three distal aesthetascs ; conspicuous spine mediallyand stylocerite forming on proximal external margin of first segment of peduncle. Antenna 2 (Fig. 3d) : exopodite with distal part divided into only three short segments. Pereiopods 1 , 2 (Figs 3k, 1) : endopodite with internal distal margin of propodus produced slightlyforward (will become fixed finger of chela). Pereiopod 3 (Fig. 3m) : developed, with natatory exopodite. Abdomen (Figs 3a, b) : somite six divided from telson by suture. Telson (Fig. 3p) : narrower, but still broader distally, outer pair of spines on posterior marginconsiderably reduced: uropod endopodite with no marginal setae', exopodite with marginal, plumosesetae. ZOEA 4 (Figs 4, 5) 5-2 mm (4-9-5-5 mm) Carapace (Figs 4a, b) : three dorso-medial spines with small retrorse teeth ventrally. Antenna 2 (Fig. 5b) : endopodite with 3-segmented flagellum (usually), as long as scaphocerite,distal part of exopodite divided into two, one or no short segments. Pereiopods 1, 2 (Figs 5f, g): endopodite with internal distal margin of propodus producedforward to over half length of dactylus (excluding terminal setae). Pereiopod 4 (Fig. 5i) : developed with natatory exopodite. Abdomen (Figs 4b, 5k-o) : pleopods on somites 1-5 rudimentary, biramous. Telson (Fig. 5p): a little broader distally than proximally, posterior margin weakly concavewith 5+5 large spines and with 2 smaller spines on latero-distal margin; endopodite and exopoditeof uropod both with marginal plumose setae. ZOEA. 5 (Figs 6, 7, 8) 5-8 mm (5-5-6-0 mm) Carapace (Fig. 6b) : setae in angles of two anterior dorso-medial spines. * In a previous paper (Fincham, 1977) two aesthetascs were recorded distally on the flagellar segment of antenna1 in zoea 1 ofPalaemon (Palaeander) elegans. Examination of more material, including specimens from the MarmaraSea, Turkey, indicate that three aesthetascs is the usual number (one wide, two narrow). LARVAL DEVELOPMENT OF PALAEMONETES VARIANS 167 Fig. 2 Zoea 2: (a) dorsal view; (b) lateral view; (c) antenna 1 ; (d) antenna 2; (e) mandibles; (f)maxilla 1; (g) maxilla 2; (h) maxilliped 1; (i) maxilliped 2; (j) maxilliped 3; (k) pereiopod 1;(1) pereiopod 2; (m) pereiopod 3; (n) pereiopod 4; (o) pereiopod 5; (p) telson. Bar scales: a, b0-5 mm; c, d, h-p = 0-2 mm; f, g = 0-l mm; e = 0-05 mm. 168 A. A. FINCHAM Fig. 3 Zoea 3: (a) dorsal view; (b) lateral view; (c) antenna 1; (d) antenna 2; (e) mandibles; (f)maxilla 1 ; (g) maxilla 2; (h) maxilliped 1 ; (i) maxilliped 2; (j) maxilliped 3; (k) pereiopod 1 ; (1)pereiopod 2; (m) pereiopod 3; (n) pereiopod 4; (o) pereiopod 5; (p) telson. Bar scales: a, b =0-5 mm; c, d, h-p = 0-2 mm; f, g = 0-l mm; e=0-05 mm. LARVAL DEVELOPMENT OF PALAEMONETES VARIANS 169 Fig. 4 Zoea 4: (a) dorsal view; (b) lateral view; (c) mandible; (d) maxilla 1 ; (e) maxilla 2.Bar scales: a, b = 0-5 mm; c = 0-05 mm; d, e = 0-l mm. 170 A. A. FINCHAM m Fig. 5 Zoea 4: (a) antenna 1 ; (b) antenna 2; (c) maxilliped 1 ; (d) maxilliped 2; (e) maxilliped 3;(f) pereiopod 1 ; (g) pereiopod 2; (h) pereiopod 3; (i) pereiopod 4; (j) pereiopod 5; (k) pleopod 1 ;(1) pleopod 2; (m) pleopod 3; (n) pleopod 4; (o) pleopod 5; (p) telson. Bar scale: a-p = 0-2 mm. LARVAL DEVELOPMENT OF PALAEMONETES VARIANS 171 Fig. 6 Zoea 5: (a) dorsal view; (b) lateral view; (c) mandible; (d) maxilla 1 ; (e) maxilla 2.Bar scales: a, b = 0-5 mm; c = 0-05 mm; d, e = 0-l mm. 172 A. A. FINCHAM n Fig. 7 Zoea 5: (a) antenna 1 ; (b) antenna 2; (c) maxilliped 1 ; (d) maxilliped 2; (e) maxilliped 3;(f) pereiopod 1 ; (g) pereiopod 2; (h) pereiopod 3; (i) pereiopod 4; (j) pereiopod 5; (k) pleopod 1 ;(1) pleopod 2; (m) pleopod 3; (n) pleopod 4; (o) pleopod 5. Bar scale: a-o = 0-2 mm. LARVAL DEVELOPMENT OF PALAEMONETES VARIANS 173 Fig. 8 Zoea 5: (a) telson. Post larva 1 : (b) telson. Bar scale: a, b = 0-2 mm. 174 A. A. FINCHAM Antenna (Fig. 7a) : circlet of plumose setae developed dorsally on first segment of peduncle,indicating position of statocyst. Antenna 2 (Fig. 7b) : increase in number of segments of endopodite flagellum, just longer thanscaphocerite. Pereiopods 1, 2 (Figs 7f, g): endopodite with immovable finger of propodus produced forward toalmost length of dactylus (excluding terminal setae). Abdomen (Figs 6a, b, 7k-o) : pleopods with rudimentary setae on margins of exopodite, endo-podite ofpleopods 2-5 with rudiment of appendix interna (stylamblys). Telson (Fig. 8a): further narrowing distally, posterior margin still weakly concave with 4+4large spines and with 3 smaller spines on latero-distal margin. POST LARVA 1 (Figs 8, 9, 10, 11) 6-4 mm (6-0-7-0 mm) Carapace (Figs 9a, b) : rostrum with 3-6 dorsal and 1-2 ventral spines, supraorbital spines missing. Antenna 1 (Fig. 10a): internal flagellum of 2-4 segments and usually an additional group of 2aesthetascs distally on first segment of external flagellum. Antenna 2 (Fig. lOb): endopodite with flagellum multisegmented, more than twice length ofscaphocerite. Mandible (Fig. 9c): divided into pars incisiva and pars molaris, lacinia mobilis no longer present. Maxilliped 2 (Fig. lOd): endopodite with dactylus, propodus and merus flattened, exopoditeshortened and with no setae. Maxilliped 3 (Fig. lOe): endopodite dactylus shortened, exopodite reduced to less than halflength of endopodite, and without setae. Pereiopods 1, 2 (Figs lOf, g): ischium, merus and carpus lengthened, exopodite reduced to aboutthe length of the ischium of endopodite and with no setae. Pereiopods 3, 4 (Figs lOh, i): endopodite dactylus evenly tapering distally, propodus, carpusand merus lengthened, exopodite reduced, extending halfway along ischium of endopodite, setaegenerally absent but with a few small, plumose setae sometimes present. Pereipod 5 (Fig. lOj): dactylus evenly tapering distally, other segments of endopodite length-ened. Pleopod 1 (Fig. 11 a): ratio of endopodite to exopodite 1 : 4, endopodite bearing terminalplumose setae, exopodite fringed with long plumose setae. Pleopods 2-5 (Figs 1 Ib-e): endopodite over half length of exopodite, both with long, marginal,plumose setae, endopodite with appendix interna bearing well-developed intero-distal couplinghooks. Telson (Fig. 8b) : narrow, posterior margin convex with a short, median point, 1 + 1 large spinesand two pairs of setae on the posterior margin, one long and plumose, other simple, also 3 smallerspines on latero-distal margin. POST LARVA 2 (Fig. 11) 7-2 mm (6-8-7-9 mm) Maxillipeds, 2, 3 : exopodites lengthen and regain marginal, plumose setae.Pereiopods 1-4: exopodites continue to diminish.Telson (Fig. llg): extremely narrow, median point on posterior margin more pronounced. POST LARVA 5 (Fig. 1 1) Antenna 1 (Fig. llh): development of accessory flagellum on external flagellum. Antenna 2 (Fig. Hi): morphogenesis of exopodite complete - truncated distally, edges almostparallel. Discussion Results of the present study are summarized in Tables 1 and 2. The temporary regression of theexopodites of maxillipeds 2 and 3, in which shortening occurred with loss of marginal plumosesetae and also the disappearance of the natatory exopodites of pereiopods 1-4, paralleled exactlythe changes at first post larval moult (PL 1) for Palaemon (Palaeander) elegans (Fincham, 1977).The relatively abbreviated development of Palaemonetes (Palaemonetes) varians compared withthe 6-9 stages of Palaemon (Palaeander) elegans is accompanied by a change in the sequence of LARVAL DEVELOPMENT OF PALAEMONETES VARIANS 175 Fig. 9 Post larva 1 : (a) dorsal view; (b) lateral view; (c) mandible; (d) maxilla 1 ; (e) maxilla 2.Bar scales: a, b = 0-5 mm; c = 0-05 mm; d, e = 0-l mm. 176 A. A. FINCHAM Fig. 10 Post larva 1 : (a) antenna 1 ; (b) antenna 2; (c) maxilliped 1 ; (d) maxilliped 2; (e) maxilliped3; (f) pereiopod 1 ; (g) pereiopod 2; (h) pereiopod 3; (i) pereiopod 4; (j) pereiopod 5. Bar scale:a-j = 0-2 mm. LARVAL DEVELOPMENT OF PALAEMONETES VARIANS 111 Fig. 11 Post larva 1 : (a) pleopod 1 ; (b) pleopod 2; (c) pleopod 3; (d) pleopod 4; (e) pleopod 5.Post larva 2: (f) rostrum; (g) telson. Post larva 5: (h) antenna 1 (aesthetascs drawn, setaeomitted); (i) antenna 2 (setae omitted.) Bar scale: a-i = 0-2 mm. 178 A. A. FINCHAM Table 1 Larval development and range of morphological variation in Palaemonetes (Palaemonetes)varians Zoea/Stage PL1 Supraorbital spines + / No. of antero-lateral spines Rostrum tip - Ventral retrose hooks +/ Antenna 1 No. of groups, aesthetascsStylocerite + /-Statocyst +/-Medial spine + /No. of segments, flagellum - Internal ExternalAccessory flagellum +/ Antenna 2Endopodite - No. of segments c.f. Length of scaphocerite Exopodite - No. of distal segmentsNo. of plumose setaeExternal spine +/ Mandible - Lacinia mobilis + /Maxilla 1 1-2 10-50 59 20-50 416-18 3 0-66 -0-75 2 18-21 5 1-0-1-25 21-23 pereiopod development. Limb buds were present in zoea 1, and at zoea 2 only pereiopods 3 and4 were still rudimentary. At zoea 3 pereiopod 3 was fully developed together with a functionalnatatory exopodite, and at zoea 4 pereiopod 4 was fully formed also. The change to adult-typemandible (Fig. 9c) is made at the moult to PL 1 and is associated with the change in diet neces-sitated by the major behavioural change from a planktonic to largely benthic existence. LARVAL DEVELOPMENT OF PALAEMONETES VARIANS Table 1 (cont.) 179 Zoea/Stage PL1 Maxilliped 2 Endopodite - No. of segmentsExopodite +/Setae +/- Maxilliped 3 Endopodite - No. of segmentsExopodite +/Setae +/- Pereiopods 1 &2 +/-Biramous +/Endopodite - Propodus fixed finger + / Pereiopod 3 +/Biramous + / Pereiopod 4 + /Biramous + /- Pereiopod 5 +/Biramous +/ AbdomenSomite 5 - Lateral spines + / R+ R+ R+ R+ R+ R+ R+ R+ R+R+ + + + Rate of epigenesis In order to transform zoea 1 to a miniature adult or juvenile, a definite sequence of morpho-genetic and associated biochemical and physiological development and adaptation has to becompleted. If larvae moult 'early', less of the developmental sequence is completed. Epigenesis inCrustacea is a continuous sequential process despite being apparently arrested at morphological 180 A. A. FINCHAM Table 2 Analysis of morphometric variation (a) in overall size in mm and meristic variation in the numberof expedite plumose setae of (b) antenna 2, (c) uropod and (d) maxilla 2 during the development to postlarva of Palaemonetes (Palaemonetes) varians (n.d. = not developed; see Materials and Methods forstatistical abbreviations) Stage PL1 stages during the intermoult period of ecdysis. Moulting and epigenesis become desynchronizedafter the first few zoeal stages. This results in morphological variation in larvae with similarmoulting histories (in terms of the number of moults), but in which epigenesis may have beenproceeding at different rates. Also, the longer an intermoult period lasts so the next stage is moreadvanced. Superimposed on this is normal intraspecific variation including variation within abrood from one female. The separate control of development and moulting is adaptive in that larvae are able to copewith sub-optimal conditions by slowing epigenetic development while continuing to moult. Theanimal is constrained physically by the rigid exoskeleton and moulting is essential to permit anincrease in size. Epigenesis may be delayed, but moulting continues and may not always beaccompanied by an increase in size. This results in so called 'repeat' moults (Rochanaburanon &Williamson, 1976; Fincham, 1977). As moulting uses up energy and increases vulnerability untilthe exoskeleton hardens after ecdysis, it is reasonable to assume that moulting has functionsother than merely allowing an increase in size. It is not clear why moulting does not cease in poorconditions. It has been shown, from analysis of whole larvae, however, that organic substancesincluding proteins and amino acids and inorganic ions such as K+. Ca ++ , Mg ++ rise in concen-tration during premoult and decrease at postmoult, and the reverse occurs in concentrations forNa+ and Cl~ (Torres, 1973; Charmantier, 1977). The periodic release into the haemolymph ofthese molecules and ions may be necessary to make them available for stages in the epigeneticsequence. This leads to the development of the new structures, which in the larval stages is con-tinuous even if, in response to poor external environmental conditions, the rate is slow. Meristic and morphological variation (Tables 1, 2) In a study of morphological variation in natural populations of the smooth newt, Bell (1974)found that animals of average length survive in conditions of stress such as the critical period ofmetamorphosis. As the total length increases, therefore, so variation in this character would beexpected to decrease. Waddington (1948) pointed out that development is canalized with a strongtendency for the adult to conform to the morphological norm within prescribed limits. In a laterpaper Waddington (1953) discussed the inflexibility of the biochemical pathways controlled by theepigenotype during development. These pathways lead inevitably to a similar end result, to a LARVAL DEVELOPMENT OF PALAEMONETES VARIANS 181 large extent regardless of unfavourable influences from the genotype or the environment. Bell(1974) stated that '. . . the epigenetic system is so constructed that individuals which are originallyquite different tend to become more similar as their development proceeds'. Both developmental canalization (stabilizing selection) and natural (normalizing) selection havethe effect of reducing variation. Bell (1974), however, was able to eliminate the former in account-ing for the decrease in variation in the two morphometric characters (standard length and headwidth) as the larvae approached metamorphosis. This was achieved by keeping laboratory popu-lations of newt larvae in near optimum conditions. Overall survival was better than for equivalentwild populations since external natural selection was less intense in the laboratory, whereas theinternal stabilizing selection would have been the same in both wild and laboratory populations.This reduction in variation of larval size distribution was reversed in post-metamorphosis newtsand was corroborated by dentition data (Bell, 1975). The obvious advantage of such selectiveprocesses is that only typical representatives of the species survive metamorphosis. The present morphometric results (Table 2) parallel the findings of Bell and show that there isa significant reduction (P < 0-05) in variation or normalizing selection of larval size as Palae-monetes (Palaemonetes) varians approached metamorphosis, with a tendency to increase in post-metamorphosis shrimps. All other correlations of meristic characters were not significant andthere was no tendency for individuals to become more similar as suggested by Bell (1974). Par-ticular attention was given to the shrimp mouthparts since Bell (1975) found newt dentition datacorroborated his morphometric findings. To compare these results of Palaemonetes (Palaemonetes)varians, data (Fincham, 1977) from a closely related palaemonid Palaemon (Palaeander) eleganswas analysed to test for changes in variation as metamorphosis approached. In the latter specieseven morphometric data were not significant. There was, however, a significant increase invariation of the plumose setae on the exopodite of mouthpart maxilla 2 in the pre-metamorphosisstages (P<0-01). Clearly there is no simple, general correlation between larval variation andthe approach of metamorphosis. Some similarities in habitat exist between the newt and Palaemonetes (Palaemonetes) varians \both live in shallow ephemeral bodies of water and both showed a reduction in overall lengthvariation. A rigorous selection process may be necessary to ensure survival in this particularhabitat. The increase in variation of maxilla 2 in P. (P.) elegans - a genuine increase and notsimply a corollary of increased size - presents a totally unexpected reversal of normalizing selec-tion. This shrimp is a common inhabitant of intertidal rockpools and undergoes 6-9 zoeal moultsbefore metamorphosis. The larvae are planktonic and have access to a wide variety of coastalhabitats when they become benthic after the final larval stage. There is a degree of uncertainty inmaking immediate contact with the most suitable rocky coastline and a degree of variation wouldclearly be advantageous. Gurney (1924) stated '. . . a knowledge of the larval history is of importance in tracing thesystematic relationships of Decapoda . . .'. One of the aims of this present series of papers is toprovide detailed descriptions of larval stages to aid identification and to form the basis of asystematic study using numerical methods. For this purpose the extent of larval variation needsto be determined. Gurney (1924) gave details of intermediate post larval stages in which variouscombinations of late larval and first post larval characters were found. While these were notunknown in the present study, rearing at 22 C produced a rapid, and in most cases direct,development to PL1 through five larval stages. The delay in the epigenetic process recorded byGurney was probably a response to environmental stress imposed by the rearing techniques.With regard to larval polymorphism or poecilogony (Boas, 1889; Heldt, 1953) abundant larvalvariation was recorded in the present study but this did not exceed variability commonly foundin larval prawns and shrimps. Acknowledgement It is a pleasure to thank Peter Warren, MAFF Fisheries Laboratory, for introducing me toBurnham-on-Crouch ditches and Ann Gurney, BM(NH) Crustacea Section, for assisting ablywith larval rearing. 182 A. A. FINCHAM References Allen, E. J. 1893or. Preliminary account of the nephridia and body cavity of the larva of Palaemonetes variant. Proc. R. Soc. 52 : 338-342. 18936. Nephridia and body cavity of some decapod Crustacea. Q. Jl microsc. Sci. 34 : 403-426. Bell, G. 1974. The reduction of morphological variation in natural populations of Smooth newt larvae. /. Anim. Ecol. 43:115-128. 1975. 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A tabular view of the external characters of four classes of animals, which Linn6 arranged under Insecta; with the distribution of the genera comprising three of these classes into orders etc., and descriptions of several new genera and species. Trans. Linn. Soc. Land. 11 : 306-400.Le Roux, A. 1970. Contribution a 1'etude du developpement larvaire de Palaemonetes varians (Leach) (Decapoda, Palaemonidae). C. r. hebd. Seanc. Acad. Sci., Paris 270D : 851-854.Mayer, P. 1880. Carcinologische Mittheilungen. IX. Die Metamorphosen von Palaemonetes varians (Leach). Mitt. zool. Stn Neapel. 2 : 197-221.Rochanaburanon, T. & Williamson, D. I. 1976. Laboratory survival of Palaemon elegans Rathke and other caridean shrimps in relation to their distribution and ecology. Estuar. cst. mar. Sci. 4 : 83-91.Sol laud, E. 1914. Recherches sur 1'ontogenie des Caridea; relation entre du vitellus nutritif de 1'oeuf et 1'ordre d'apparition des appendices abdominaux. C. r. hebd. Seanc. Sci., Paris 158 : 971-973.1919. Influence des conditions du milieu sur les larves du Palaemonetes varians microgenitor Boas. C. r. Hebd. Seanc. Sci., Paris 169 : 735-737.1921. Le comportement des larves de Palaemonetes varians microgenitor, Boas. Changement de signe du phototropisme apres la metamorphose. Rapp. pres. Congr. Ass. fr. Avanc. Sci. Rouen, 1921 : 671-673. 1923a. Le developpement larvaire des Palaemoninae. Bull. biol. Fr. Belg. 57 : 509-603. 19236. Ce qu'il faut penser du 'polymorphisme' poecilogonique du Palaemonetes varians (Leach). C. r. hebd. Seanc. Acad. Sci. Paris 178 : 125-128. 1930. La legende du 'Polymorphisme poecilogonique' de Palaemonetes varians (Leach); distribution de ce Crustace sur nos cotes. Bull. Soc. sclent. Bretagne 7 : 1-6.Torres, C. 1973. Variations du pool des acides amines libres du muscle abdominal de Penaeus kerathurus au cours du cycle d'intermue et au cours du jeune. Comp. Biochem. Physiol. 45B : 1-12.Waddington, C. H. 1948. The genetic control of development. Symp. Soc. exp. Biol. 2 : 145-154. 1953. Epigenetics and evolution. Symp. Soc. exp. Biol. 1 : 186-199. Weldon, W. F. R. 1890. Palaemonetes varians in Plymouth. /. mar. biol. Ass. U.K. 1 (4) : 459-461.Weygoldt, P. 1961. Beitrag zur Kenntnis der Ontogenie der Dekapoden: Embryologische Untersuchungen an Palaemonetes varians (Leach). Zool. Jb. 79 : 223-270. Manuscript accepted for publication 17 May, 1977 A revision of the spider genus Brettus(Araneae : Salticidae) F. R. Wanless Department of Zoology, British Museum (Natural History), Cromwell Road, London SW7 5BD Introduction The genus Brettus was proposed by Thorell (1895) for the Burmese species Brettus cingulatusThorell. Simon (1900) described four more species (Brettus martini from South Africa, B. albolim-batus and B. semifimbriata from India and B. adonis from Sri Lanka) and in 1901 synonymizedthe genus with Portia. Wanless (19786) revised Portia and resurrected Brettus in part. Brettusmartini Simon could not be recognized from the original description and as the type specimencould not be found the name was considered a nomen dubium. In the present paper the genus isredefined and its affinities discussed. The four known species (of which one is new) are describedand keyed. One species is newly synonymized and three lectotypes designated. The measurements were made in the manner described by Wanless (1978#). The known species of Brettus are closely related and occur in the Oriental region. They resemblespiders of the genus Portia, but are generally smaller in size and lack the abdominal hair tufts.Unfortunately their biology is unknown though it is considered that their behaviour may besimilar to that described for some species of Portia (Wanless, 19786), and that specimens may befound living in diplurid or pholcid webs. Genus BRETTUS Thorell Brettus Thorell, 1895 : 354. Type species Brettus cingulatus Thorell, by original designation and monotypy.Simon, 1901 : 402 [= Portia] Petrunkevitch, 1928 : 213. Bonnet, 1955 : 915. Wanless, 19786 : 84[gen. rev.]. DEFINITION. Small to medium spiders ranging from about 3-0 to 8-0 mm in length. Sexes alike;leg fringes present, but abdominal hair tufts apparently lacking; colour patterns composed ofsetae (easily rubbed). Carapace : high, longer than broad ; fovea present, behind posterior lateraleyes ; sculpturing not marked, cuticle weakly iridescent (under some angles of illumination) ; inmost species, broad marginal bands composed of white setae extend from clypeal region toposterior thoracic margin. Eyes: anteriors subcontiguous with apices recurved; posterior medianeyes relatively large, nearer to anterior laterals than to posterior laterals ; posterior row narrowerthan anterior row; quadrangle length between 40 and 50 per cent of carapace length. Clypeus:moderately high to high, concave. Chelicerae : medium to large, more or less vertical ; promarginwith 3 teeth, retromargin with 3 to 4. Maxillae : elongate, usually divergent. Labium : subtriangular,about half maxilla length. Sternum: elongate scutiform. Pedicel: short. Abdomen: elongateovoid; scuta lacking, but four impressed spots usually present; anterior and posterior spinneretsrobust, subequal in length, medians slender, relatively short; trachea not examined (insufficientmaterial). Legs : long and slender, fringes present on legs I and sometimes II ; spines numerous,moderately robust; claws pectinate, tufts present, scopula lacking; legs I-II with minute setae inparallel row on venter of tarsi and metatarsi. Female palp : long and slender with terminal claw(difficult to see). Male palp: femoral apophyses lacking; tibiae with lateral and ventral apophyses,the former with an associated duct which appears to arise from a flask-like vacuole (Fig. IE, F).Cymbium modified proximally; embolus very long and slender; conductor apparently lacking;tegulum with peripheral seminal reservoir, a curved furrow (Fig. 1A, B) and a bipartite mem-braneous apophysis (apparently lacking in B. adonis) adjacent to the embolic base; median Bull. Br. Mus. not. Hist. (Zool.) 35 (2): 127-200 Issued 26 April, 1979 183 184 F. R. WANLESS B H Fig. 1 (A, C, E, G) Brettus cingulatus Thorell, holotype <?: (A) palp, ventral view; (C) palp, mesalview; (E) palpal tibia, posterior view; (G) palp, ectal view. (B, D, F, H) B. adonis Simon, $: (B)palp, ventral view; (D) palp, mesal view; (F) palpal tibia, dorsolateral view; (H) palp, ectal view. apophysis lacking. Epigyne: relatively simple; openings usually indistinct, leading to elongateducts which terminate distally as spermathecae. AFFINITIES. Wanless (19786) suggested that on behavioural and anatomical grounds Portia,Brettus, Cocalus and several other genera with large posterior median eyes could be related tolyssomanid spiders and that Brettus may form a link between Portia in the Salticidae and Ase-monea in the Lyssomanidae. Unfortunately the link cannot be satisfactorily demonstrated fromthe known species of Brettus which are evidently closer to Portia than to Asemonea. Preliminary SPIDER GENUS BRETTUS 185 observations on male Asemonea have shown that the palps are generally very complex and thatsome males (e.g. A. tenuipes O.P.-C.) apparently have ducts associated with the femoral apophyses.The presence of these ducts may indicate a distant relationship with Brettus, but their significancecannot be evaluated at the present time. DIAGNOSIS. Brettus is distinguished from Portia by the very long embolus and the apophysal ducton the tibiae in males, and the long fertilization ducts in females. A fuller diagnosis cannot begiven until other related genera have been revised. List of species in the genus Brettus Thorell, 1895 Brettus adonis Simon, 1900B. albolimbatus Simon, 1900B. anchorum sp. n.B. dngulatus Thorell, 1895 Key to speices of Brettus 1 Males- 2 - Females 3 2 Retrolateral tibial apophysis not bifurcate, ectal margin of cymbium with pointed spur (Fig. 1 G) (Burma) dngulatus Thorell (p. 185) - Retrolateral tibial apophysis bifurcate, ectal margin of cymbium lacking pointed spur (Fig. 1H) (Sri Lanka) adonis Simon (p. 186) 3 Distal margin of epigynal plate clearly projecting beyond epigastric fold (Fig. 3A) (Sri Lanka) adonis Simon (p. 186) - Distal margin of epigynal plate not projecting beyond epigastric fold ..... 4 4 Spermathecae extending laterally (Figs 3B; 4C, D) (India) . . anchorum sp. n. (p. 188) - Spermathecae extending anteriorly (Figs 3C, D; 4A, B) (India) . . albolimbatus Simon (p. 188) Brettus dngulatus Thorell(Figs 1A, C, E, G;2A,B) Brettus dngulatus Thorell, 1895 : 355, <J. Holotype <J, Burma, Tharrawaddy (NR, Stockholm, no. 1605) [Examined]. Wanless, 19786 : 83.Portia dngulata: Simon, 1901:402. Reimoser, 1925:90. Roewer, 1954:934. Bonnet, 1958:3766. Proszyriski, 1971 :461. DIAGNOSIS. The male of B. dngulatus is readily distinguished from that of Brettus adonis by thepointed spur on the ectal margin of the cymbium (Fig. 1G). FEMALE. Unknown. MALE HOLOTYPE. Carapace (Fig. 2A, B) : orange-brown with paler eye region and a wide marginalband composed of recumbent, silky white hairs from clypeus to posterior thoracic margin.Eyes: with black surrounds except AM; anteriors fringed by whitish hairs. Clypeus: denselyclothed in silky white hairs. Chelicerae: orange-brown; thinly covered in fine light brown hairs;promargin with 3 teeth, retromargin with 4. Maxillae and labium : pale orange-brown tinged withgrey. Sternum : light orange-brown with poorly defined reddish orange margins ; sparsely clothedin dull white hairs. Abdomen: rubbed; light yellow-orange tinged with black; pattern indistinct.Legs: anteriors dark orange-brown, posteriors lighter; brown ventral fringes present on femora,patellae and tibiae of legs I and II; spines numerous, moderately robust. Palp (Fig. 1A, C, E, G).Dimensions (mm): total length 5-6; carapace length 2-56, breadth 2-2, height 1-48; abdomenlength 2-88; eyes anterior row 1-44, middle row 1-08, posterior row 1-28; quadrangle length 1-08.Ratios: AM : AL : PM : PL : 12-5 : 6-5 : 5 : 6; AL-PM-PL : 6-5-9. DISTRIBUTION. Burma. MATERIAL EXAMINED. Holotype & data given in synonymy. 186 F. R. WANLESS Brettus adonis Simon comb. rev.(Figs IB, D, F, H;2D, E;3A) Brettus adonis Simon, 1900 : 32, ?, LECTOTYPE ? (here designated) Sri Lanka, Galle (MNHN, Paris, no. 20416) [Examined].Portia adonis (Simon): Simon, 1901 : 402. Roewer, 1954 : 934. Bonnet, 1958 : 3766. Proszyriski, 1971 : 461. Fig. 2 (A, B) Brettus cingulatus Thorell, holotype (J : (A) carapace, dorsal view ; (B) carapace, lateralview. B, albolimbatus Simon, lectotype ? : (C) carapace, lateral view. (D, E) B. adonis Simon, <? :(D) carapace, dorsal view; (E) carapace, lateral view. B. anchorum sp. n. holotype ?: (F) carapace,lateral view. The vial labelled '20416 Port Adonis [sic] E. S. Galle type' contains one male and one female.The female is considered to be the type specimen and is designated lectotype. The male, whichappears to be conspecific, is described below. DIAGNOSIS. B. adonis is distinguished from Brettus cingulatus by the absence of a pointed spur onthe ectal margin of the cymbium in males (Fig. 1H), and the posterior projection of the epigynalplate in females (Fig. 3A). MALE FROM GALLE, SRI LANKA. Carapace (Fig. 2D, E): light orange with yellow-orange eye region;very sparsely clothed in minute iridescent setae (mostly rubbed). Eyes: with black surroundsexcept AM; anteriors fringed by pale yellow hairs. Clypeus: fringed by short silky white hairs.Chelicerae : yellow with faint sooty markings ; fringed proximally with transverse band of silky SPIDER GENUS BRETTUS 187 white hairs; teeth not examined. Maxillae and labium: yellow tinged with grey. Sternum: yellow,glossy. Abdomen: yellow with faint blackish mottling; very sparsely clothed in minute iridescentsetae. Legs: legs I orange to pale orange, lightly tinged with black; remaining legs pale yellow;legs I densely fringed by stiff orange-brown hairs on venter and dorsum of tibiae, venter of patellaeand distal venter of femora. Spines moderately robust and numerous. Palp (Fig. IB, D, F, H).Dimensions (mm): total length 3-16; carapace length 1-65, breadth 1-28, height 0-92; abdomenlength 1-44; eyes anterior row 1-08, middle row 0-84, posterior row 0-92; quadrangle length 0-80.Ratios: AM : AL : PM : PL : 9-5 : 4-5 : 3-5 : 4; AL-PM-PL : 5-6-5. Fig. 3 Brettus adonis Simon, lectotype $: (A) epigyne. B. anchomm sp. n. holotype ?:(B) epigyne. (C, D) B. albolimbatus Simon, lectotype ?: (C) epigyne; paralectotype ?: (D) epigyne. FEMALE LECTOTYPE. Body form and colour similar to <. Carapace: as in <, but irregularly clothedwith recumbent white hairs, iridescent under some angles of illumination, apparently forming awide marginal band from clypeus to posterior thoracic margin. Eyes: more or less as in (J.Clypeus: thinly clothed in fine whitish hairs. Maxillae and labium: as in $. Sternum: as in <J.Abdomen : pale yellow with a greyish tip and markings forming an ill-defined ventral band fromspinnerets to epigyne. Legs: similar to <$ but dorsal fringes on legs I lacking and with patellae andventral tibial fringes composed of long white hairs proximally. Palps: long and slender, whitishyellow with white hairs. Epigyne (Fig. 3 A) : vulva not examined. Dimensions (mm): total length 4-6; carapace length 1-96, breadth 1-56, height 1-04; abdomenlength 2-52; eyes anterior row 1-27, middle row 0-98, posterior row 1-12; quadrangle length 0-96.Ratios: AM : AL : PM : PL : 11-5 : 6 : 4 : 5; AL-PM-PL : 6-8. DISTRIBUTION. Sri Lanka. MATERIAL EXAMINED. Lectotype $, data given in synonymy. SRI LANKA: Galle, 1 $ in the samevial as the lectotype. 188 F. R. WANLESS Brettus albolimbatus Simon comb. rev.(Figs 2C; 3C, D; 4A, B) Brettus albolimbatus Simon, 1900 : 31, ?. LECTOTYPE ? (here designated) India, Trichinopoly (MNHN, Paris, no. 17534) [Examined].Portia albolimbata (Simon): Simon, 1901 : 402. Roewer, 1954:934. Bonnet, 1958:3766. Proszyriski, 1971 : 461. Wanless, 19786 : 85.Brettus semifimbriatus Simon, 1900 : 31, ?. LECTOTYPE ? (here designated) India, Trichinopoly (MNHN, Paris, no. 18918) [Examined]. Syn. n.Portia semifimbriata (Simon): Simon, 1901 :401, 402. Strand, 1912: 148. Roewer, 1954:934. Bonnet, 1958 : 3767. Wanless, 19786 : 85.Portia foveata Strand, 1912 : 148. [Published as a synonym of P. semifimbriata (Simon).] The vial labelled '17534 Port. Scultzi Karch [sic] (albolimbata E. S. type) Natal C.M.' containsone female which is conspecific with the lectotype of Brettus semifimbriatus Simon. In view of thisconspecificity and the reference to 'albolimbata E. S. type' on the label, the locality and collectordata, i.e. Natal, C[h]. M[artin], is probably erroneus and the specimen is considered to be thetype of B. albolimbata. DIAGNOSIS. B. albolimbatus, known only from the female, is distinguished from other females ofBrettus by the S-shaped fertilization ducts and the anteriorly extended spermathecae (Figs 3C, D;4A,B). " MALE. Unknown. FEMALE LECTOTYPE. Carapace (Fig. 2C) : light orange-brown with yellow-orange eye region andfaint sooty marking radiating from fovea; shiny and weakly iridescent under some angles ofillumination; from AL to posterior thoracic margin a broad white marginal band composed ofrecumbent white hairs. Eyes: with black surrounds except AM; anteriors fringed by whitishhairs. Clypeus: thinly covered in white hairs. Chelicerae: pale orange-brown with sooty markings;sparsely clothed in long fine pale orange hairs; pro- and retromargins with 3 teeth. Maxillae andlabium: light orange-brown tinged with grey. Sternum: light orange-brown, shiny; thinly clothedin fine Light orange hairs. Abdomen: whitish yellow tipped with grey, with greyish markings dor-sally and subparallel bands from epigyne to spinnerets; irregularly clothed in white and orange-brown hairs (rubbed). Legs: pale yellow to orange-brown with ventral brown fringes on tibiae I,patellae I and femora I; similar fringes on legs II, but less dense; spines numerous, moderatelyrobust. Palp: white with yellowish tips. Epigyne (Fig. 3C). Dimensions (mm): total length 5-04; carapace length 2-4, breadth 2-0, height 1-4; abdomenlength 2-76; eyes anterior row 1-44, middle row 1-14, posterior row 1-26; quadrangle length 0-98.Ratios: AM : AL : PM : PL : 12-5 : 6 : 5 : 5-5; AL-PM-PL : 7-9. VARIATION. Females vary from 5-04 to 7-2 mm total length, 2-4 to 2-9 mm carapace length (threespecimens). The appearance of the epigynal fertilization ducts is evidently variable (Fig. 3C, D). DISTRIBUTION. India. MATERIAL EXAMINED. Lectotype females, data given in synonymy. INDIA : Madras, Trichinopoly,1 $ paralectotype in the same vial as the lectotype of B. semifimbriatus (no. 18918). Brettus anchorum sp. n.(Figs3B;4C,D) DIAGNOSIS. B. anchorum, known only from the female is separated from other females of Brettusby the laterally extended spermathecae (Figs 3B; 4C, D). MALE. Unknown. FEMALE HOLOTYPE. Carapace (Fig. 2F) : pale orange with yellowish eye region and broad marginalbands of recumbent white hairs from AM to posterior thoracic margin. Eyes: with black surrounds SPIDER GENUS BRETTUS 189 except AM; anteriors fringed by white hairs. Clypeus: thinly clothed in whitish hairs. Chelicerae:pale orange with long fine white hairs; promargin with 3 teeth, retromargin with 4. Maxillae andlabium: pale orange tinged with grey. Sternum: light yellow, shiny. Abdomen: whitish yellow.Legs: whitish yellow to orange; tibiae I, patellae I and distal half of femora I ventrally fringedby stiff orange-brown hairs. Palp: light yellow. Epigyne (Figs 3B; 4C, D). Dimensions (mm): total length 7-82; carapace length 2-72, breadth 2-36, height 1-48; abdomenlength 4-7; eyes anterior row 1-4, middle row 1-08, posterior row 1-26; quadrangle length M2.Ratios: AM : AL : PM : PL : 13 : 6 : 5 : 6; AL-PM-PL : 7-9-5. Fig. 4 (A, B) Brettus albolimbatus Simon, paralectotype ?: (A) vulva, ventral view; (B) vulva,dorsal view. (C, D) B. anchorum sp. n. holotype ?: (C) vulva, ventral view; (D) vulva, dorsal view. DISTRIBUTION. India. MATERIAL EXAMINED. Holotype $, India, Madras, Nilghiri Hills (Sir George Hampson) (BMNH.Reg. No. 1977.12.21.1). Acknowledgements I wish to thank the following colleagues for providing specimens for study. M. M. Hubert,Museum national d'Histoire naturelle, Paris, France (MNHN, Paris) and Professor T. Krone-stedt, Naturhistoriska Riksmuseet, Stockholm, Sweden (NR, Stockholm). References Bonnet, P. 1945-61. Bibliographia Araneorum, 3 vols. Imprimerie Douladoure, Toulouse. Petrunkevitch, A. 1928. Systema Aranearum. Trans. Conn. Acad. Arts Sci. 29 : 1-270. Proszynski, J. 1971. Catalogue of Salticidae (Aranei) specimens kept in major collections of the world. Annls zool Warsz. 28 : 367-519. Reimoser, E. 1925. Fauna sumatrensis. Supplta ent. 11 : 89-94.Roewer, C. F. 1954. Katalog der Araneae, 2, Abt. B : 924-1290. Institut Royal des Sciences Naturelles de Belgique, Bruxelles. 190 F. R. WANLESS Simon, E. 1900. Etudes arachnologiques. 30e Memoire (1) XLVII. Descriptions d'especes nouvelles de la famille des Attidae. Annls Soc. ent. Fr. 69 : 27-61. 1901. Histoire naturelle des Araignees, 2 (3) : 381-668. Roret, Paris: Libraire Encyclop6dique. Strand, E. 1912. Ober einige Spinnen aus Travancore in Indien. Arch. Naturgesch. 78A (8) : 144-148.Thorell, T. 1 895. Descriptive catalogue of the spiders of Burma. British Museum (Natural History). 406 pp.Wanless, F. R. 19780. A revision of the spider genera Belippo and Myrmarachne (Araneae: Salticidae) in the Ethiopian region. Bull. Br. Mus. nat. Hist. (Zool.) 33 (1) : 1-139.19786. A revision of the spider genus Portia (Araneae: Salticidae). Bull. Br. Mus. nat. Hist. (Zool.) 34 (6) : 83-124. Manuscript accepted for publication 10 November, 1977 Notes on the osteology of the Arab horse withreference to a skeleton collected in Egyptby Sir Flinders Petrie Juliet Clutton-Brock Department of Zoology, British Museum (Natural History), Cromwell Road, London SW7 5BD,England Richard Burleigh Research Laboratory, British Museum, London WC1B 3DG, England Synopsis A horse skeleton from Egypt donated by Sir Flinders Petrie to the British Museum (Natural History)and previously assumed to be ancient has been shown by radiocarbon dating to be only about three tofour hundred years old. As a result of this, the skeleton has acquired an altogether different importanceas a rare source of comparative material relevant to the history and development of the Arab horse.Comparative measurements of the skeletons of two modern Arab horses show that these closely resemblethe Petrie horse. Other valuable osteological material collected by Petrie is briefly discussed. Introduction Amongst the material in the osteology collections of the Mammal Section at the British Museum(Natural History) is the skeleton of a horse donated by Sir Flinders Petrie, probably at thebeginning of this century. There is no documentation with the skeleton to give its historical age,date of collection or provenance beyond the fact of its having come from Egypt. The skeletonhas recently been registered in the Museum's computer catalogue of archaeological animalremains as ARC 1977 5101. The earliest evidence for the domestic horse in Ancient Egypt is at present the single skeletonfrom the Middle Kingdom fortress of Buhen in northern Sudan, dated historically to circa1675 B.C. (Clutton-Brock, 1974), and there are in fact very few remains of horses even from laterperiods in Egypt. For this reason and because the Petrie skeleton is remarkably complete, exceptfor the cranial region which is unfortunately fragmentary, we were anxious to establish its dateand locality. The age could be determined by radiocarbon dating, but the locality has proved moreelusive. There appears to be no mention of the horse skeleton in any publication by Petrie, and we haveexamined all the relevant manuscripts and other records held by the Egypt Exploration Societyand in the Petrie Museum of the Department of Egyptology at University College London. Thedocuments in the Petrie Museum have been recently catalogued by Mrs Barbara Adams (1975,pp. 108-111) and include photocopies of original journals held at the Griffith Institute, Ash-molean Museum, Oxford, the other main repository of the Petrie archives. Unfortunately, wefound no reference to the horse skeleton although there were several useful references to otheranimal remains held at the British Museum (Natural History). Despite the absence of records we considered it justifiable to proceed with the radiocarbondating in the hope that it would shed light on the early history of the horse in Egypt. To our initialdismay this date came out at only 328 radiocarbon years before the present, that is to the earlyseventeenth century A.D. It took a little time to overcome our surprise at this result, and to become reconciled to thefact that we were no longer dealing with a specimen from Ancient Egypt, but we then realizedthat the skeleton has considerable intrinsic value. This is we believe the only well-dated skeleton Bull. Br. Mus. not. Hist. (Zool.) 35 (2): 127-200 Issued 26 April, 1979 191 192 J. CLUTTON-BROCK AND R. BURLEIGH mm . f ' * : Fig. 1 The Arab mare Ajjam with Lady Wentworth. (Photo: Special Press.) of a horse that comes from the North African region, at a period when horses were beginning toundergo intensive improvement in Britain by cross-breeding with stock imported from the East.To anyone interested in the history of the Arab horse this skeleton should therefore be of value ascomparative material, for it was in about A.D. 1689 that the first of the famous Arabs, ByerleyTurk, arrived in England. As far as is known, there are no extant remains of the original importedArab horses so we have not been able to make direct metrical comparisons with contemporaryskeletons. However, detailed measurements have been recorded of the Petrie horse and comparedwith two Arab skeletons from the modern collections of the British Museum (Natural History)(Tables 1 and 2). One of these skeletons, No. 37.1.26.9, is of Ajjam, an Arab mare that died in1937. Ajjam was owned by Lady Wentworth, who as is well known, was the daughter of LadyAnne Blunt, and had a world-famous stud of imported Arab stock at Crabbet Park in Sussex(Fig. 1). We cannot be certain, of course, that the skeleton of the horse collected by Petrie in Egypt wasof Arab breed, but it can be seen from the measurements that the bones bear a close resemblanceto the two modern Arab skeletons. Osteological description The skeleton of the seventeenth century A.D. horse that was presented to the British Museum(Natural History) by Sir Flinders Petrie, was from an aged animal that was certainly more than20 years old at the time of death, and may have been more than 30 years. The age was assessed OSTEOLOGY OF THE ARAB HORSE 193 from the state of wear on the upper left corner and intermediate incisors (I 2 and I 3 ), these beingthe only incisor teeth present. The skull and upper jaws of the horse only remain as comminuted fragments, but there is enoughof the diastema region of the left maxilla and premaxilla to indicate that no canine tooth waspresent. There is therefore a high probability that the animal was female and this assertion issupported by the shape and proportions of the pelvic bones. The post-cranial bones are almostall present and are well enough preserved to enable measurements to be taken on each bone fromeither the left or right side of the skeleton. These measurements which were taken according to themethod of von den Driesch (1976), are given in Table 1, whilst the dimensions of the lower cheekteeth are given separately in Table 2. Although most of the bones were complete, their conditionwas fragile so it was decided to impregnate them with polyvinyl acetate (PVA emulsion) to con-serve them. This was carried out on the whole skeleton with the exception of the left humerus,some ribs and the right ulna which was destroyed for the radiocarbon determination. When choosing modern comparative material to be measured against the Petrie horse wedecided to take the skeleton of the Arab mare Ajjam (BM(NH) No. 37.1.26.9), although its skullwas not available for measurement, and it was immediately apparent that the bones of the twospecimens were very similar in their proportions. In addition an Arab stallion, Little Joker(BM(NH) No. H.40, presented by the Bombay Veterinary College in 1911), was selected formeasurement and in this specimen the skull is complete so its gross dimensions are included inTable 1 . The skull of the Petrie horse is unfortunately too fragmentary to allow any valid measure-ments to be recorded from it, but the mandible is complete except for the incisor region, so thismay be compared with the mandible of the stallion, Little Joker. It can be seen that the lower teethof the Petrie mare are considerably smaller than those of the stallion, but this is at least partlydue to the greater age of the mare when it died and consequently the heavier wear on its cheekteeth. Although these teeth are much worn they are healthy and show no unevenness from bitingon a bit. The Petrie skeleton is from a large horse; it stood more than 15 hands (1509 mm) at the witherswhen it was alive (Table 1) and this is high, especially for a mare. The bones show that the animalwas fine-limbed, and although it is not possible to tell the breed from an examination of theskeleton the proportions are close to those of the modern Arab mare and stallion that were takenas comparative material. The slenderness index of the metacarpal (Table 1) indicates that thePetrie mare was slightly more stockily built than the mare Ajjam, but only marginally more sothan the stallion Little Joker, and in overall height she was taller than the stallion. The numbers of vertebrae in the Petrie skeleton and the two comparative skeletons are asfollows : Petrie mare Ajjam Little Joker Cervical 777 Thoracic 18 18 17 Lumbar 5 (estimated) 5 6 The fifth lumbar vertebra is missing in the Petrie skeleton but it is evident from examination of thearticular surfaces of the fourth lumbar and the sacrum that this mare only had five lumbar verte-brae. Stecher (1962) carried out a numerical survey of the numbers of vertebrae in the spines ofmodern horses, and he provided authoritative support for the contention of horsemen that thepurebred Arab horse is 'short-coupled', that is, compared to other races of horses, it has a reducednumber of vertebrae. Stecher found that the more usual number of six lumbar vertebrae wasoften reduced to five in Arab horses, and that if six lumbars were present then the thoracic verte-brae were reduced from the more usual 18 to 17. The two skeletons of Ajjam and Little Jokerprovide examples of these two alternative numberings, whilst that of the Petrie mare is consistentwith the usual number found in the Arab breed. In both Ajjam and Little Joker the two posterior lumbar vertebrae are fully ankylosed, indi-cating that both these horses were ridden extensively before they were fully mature. Although thePetrie mare was an aged animal when it died, there is no sign of ankylosis or other pathologicalcondition in the spine which appears to be perfectly healthy. The rest of the skeleton of the Petrie 194 J. CLUTTON-BROCK AND R. BURLEIGH Table 1 Measurements of the Petrie horse skeleton together with those from male and female modernArab horse skeletons. All measurements are in mm. Figures in brackets are estimates Axis OSTEOLOGY OF THE ARAB HORSE Table 1 (cont.^ 196 Table 1 (cent.) J. CLUTTON-BROCK AND R. BURLEIGH Petrie Little Designation horse Ajjam Joker as in von den 77.5101 37.1.26.9 H.40 Driesch (1976) ? ? <J Phalanx III Fore Length GL Width GB Height in region of extensor process HP Phalanx III Hind Length GL Width GB Height in region of extensor process HP Metatarsal Length GL Lateral length GL1 Proximal width Bp Distal width Dp Min. width of shaft SD Sacrum Max. width of wings GB Length of body of sacrum withoutfirst caudal vertebra PL Slenderness index ofmetacarpalMin. width of shaft x 100/length Estimate of withers height: Humerus Lateral length x 4-87 MetacarpalLateral length x 6-41 (60-9)(83-7)(41-7) 68-9 72-847-7 288-3 2854 53-5 50-3 31-2 230-7206-4 14-00 1509-71538-4 67-574-147-8 62-971-045-8 300-0 295-0 55-3 51-0 30-6 226-0194-2 12-84 1529-21583-3 74-879-336-6 66-1 75-338-0 288-5 282-3 55-0 53-7 28-8 200-0179-0 13-45 1480-51516-6 Note: In Britain the withers height of living horses is usually measured by 'hands'. One hand= 101-6 mm. mare is also healthy with the exception of the extensive exostoses on the mandible, described inthe appendix below (see also Figs 2 and 3). Moreover, the hoof cores and anterior phalangesshow no signs of the animal having been ridden or driven over hard ground, as is usual in agedhorses that have been kept in primitive conditions and overworked. As we have not been able to discover, up to now, how this mare came to be buried nor why itwas later excavated by Sir Flinders Petrie and brought to England we can only speculate on itsorigins, but at least the healthy condition of the spine and limb bones does indicate that it wasunlikely to have been a common beast of burden. One further small piece of evidence on its demiseis provided by the tufa-like matrix that surrounded the fragments of skull. This is almost entirelycomposed of the casts of great numbers of fly larvae and pupae which have been identified byMr K. G. V. Smith of the Department of Entomology, British Museum (Natural History) asbelonging to Chrysomya albiceps (Wiedemann). This fly is found all over Africa and is a commonfeeder on carrion which means that the head of the mare must have been exposed to the open air,shortly after death, for long enough to become a breeding ground for flies that were later sealedin with sand or silt. OSTEOLOGY OF THE ARAB HORSE Table 2 Measurements of the lower teeth of the Petrie horse compared with themodern Arab male, H.40 197 Dating As mentioned above the right ulna of the horse was sacrificed to provide a sample for radio-carbon dating. The most reliable part of bone for radiocarbon dating purposes is collagen, theprotein constituent, as dates on whole bones almost invariably prove to be too young. For thisreason the olecranon process of the right ulna was first completely demineralized with dilutehydrochloric acid. A quantity of well-preserved, uncontaminated collagen was obtained whichwas converted chemically to benzene for measurement of 14 C activity by the liquid scintillationcounting method. From this measurement the following date was obtained : BM-1357. 328 52 bp (ad 1622) This result is expressed in radiocarbon years before A.D. 1950 on the basis of the 5570 year half-life, the normal mode of reporting dates at present. Thus the bp/ad notation indicates that thisdate has not been corrected for the known differences between radiocarbon and calendar years.These differences are not large in the period in which the date falls but the true calendar date towhich it is approximately equivalent will be some 80 years earlier, that is about A.D. 1 540. Thiscorrected date has in turn an estimated error of about 75 years at the level of one standarddeviation. Discussion Although we do not know the reasons for the recovery of the skeleton of the horse or whether ornot Petrie believed that it was ancient, it is not altogether surprising that he apparently kept norecord. By comparison with the splendour and interest of the objects that Petrie uncovered in the 198 J. CLUTTON-BROCK AND R. BURLEIGH Fig. 2 Lingual side of left mandibular ramus of the Petrie horse showing extent of exostosis. (Photo : Royal Veterinary College.) Fig. 3 Petrie horse. Detailed view of exostosis on ramus. (Photo : Royal Veterinary College.) OSTEOLOGY OF THE ARAB HORSE 199 course of his excavations and of which he often wrote eloquently in his journals, the animalremains must have seemed commonplace and, though in many instances worthy of retention,unworthy of special note. Similarly, the important botanical materials that Petrie found, some ofwhich are also in the collections of the British Museum (Natural History), appear to have receivedscant mention in his records. It is perhaps difficult to comprehend this today, with the presentemphasis on reconstruction of the environment and economy of earlier human populations fromexactly this kind of evidence rather than from the more material remains. Such a commentarytakes no account of course of the scale of Petrie's work, its pioneer character, the huge and im-portant collections that he made and distributed to museums in many parts of the world, and theimmense volume of material that he published over a long life of ceaseless work. He was in fact oneof the principal founders of modern archaeology. Fortunately he did record some of the skeletalmaterial he found as exemplified by the following passage from Gizeh and Rifeh (Petrie, 1907): In the cemetery some tombs full of animals' skeletons were found. All the skulls in good statewere preserved, and sent to the British Museum (Natural History). Mr. Oldfield Thomas haskindly given the following report upon them: "The skulls form a wonderfully fine set, whichwill no doubt prove of great value when some one arises with time and taste to work out suchthings in detail. I never saw so fine a series before. There are 192 cats' skulls, mostly Felisocreata, but no doubt some are F. chaus. They are, however, a wonderfully varying lot, andwould require much work for every one to be certainly and exactly determined. One might believethat the Ancient Egyptians had as many different kinds as we have now. Also 7 mongoose skulls(Mungos ichneumon), 3 wild-dog (Canis lupaster), and 1 fox (Vulpes famelicd)" The series of 192 cats' skulls was later described by Morrison-Scott (1952) but the rest of thecollections presented by Petrie to the British Museum (Natural History) remain to be studied.Although much of this material lacks documentation we are optimistic that further informationmay yet come to light. We intend to subject more specimens to radiocarbon dating in the beliefthat this will yield interesting results and contribute to our knowledge of the history of domesti-cated animals in Egypt. Petrie died in 1942, a decade before the advent of radiocarbon dating butdoubtless its application to material he collected would have greatly interested and gratified him.The continuing need to retain excavated skeletal material for possible future investigation cannotbe overstressed. In the present instance, the precise dating of the horse skeleton has endowed itwith a scientific value which Sir Flinders Petrie would have been the first to applaud. Appendix Pathological examination of the mandible of the Petrie horse A region of prominent exostosis on the left mandibular ramus of the horse (Figs 2 and 3) waskindly examined for us by Dr E. C. Appleby of the Pathology Department, Royal VeterinaryCollege, London, who reported as follows : Part of the mineralized material forming a plaque on the mandibular surface near the base ofthe cheek teeth was removed and decalcified for histological examination. This revealed a trabe-cular structure suggestive of new, superficial bone growth possibly overlying a lesion deeperin the bone. The exostosis appears to have been inflammatory in origin and may have beenthe result of an abscess at the base of a tooth or perhaps due to traumatic or other injury to theperiosteum. Somewhat similar, but much smaller, deposits elsewhere on the mandible were notexamined histologically. The condition had evidently been established for some weeks. Bonechanges of this kind are not uncommon in horses although usually associated with chronicdegenerative diseases of the joints rather than present in the facial region. Lesions on themandible of horses can occur as part of a generalized skeletal change associated with space-occupying lesions in the chest (acropachia) but, as stated in the main text above, in this case allthe other surviving bones of the horse were healthy in appearance. Acknowledgements We thank Mrs Barbara Adams and Dr D. M. Dixon of the Department of Egyptology, Univer- 200 J. CLUTTON-BROCK AND R. BURLEIGH sity College London, and Miss Mary Crawford of the Egypt Exploration Society for kindlyallowing us to consult records in their care. References Adams, B. 1975. Petrie's manuscript notes on the Koptos foundation deposits of Tuthmosis III. J. Egypt. Arch. 61 : 102-111. Glutton-Brock, J. 1974. The Buhen horse. /. arch. Sci. 1 : 89-100. Morrison-Scott, T. C. S. 1952. The mummified cats of Ancient Egypt. Proc. zool. Soc. Land. 121 : 861-867.Petrie, W. M. Flinders. 1907. Gizeh and Rifeh, p. 29. Quaritch, London. Stecher, R. M. 1962. Anatomical variations of the spine in the horse. /. Mammal. 43 : 205-219.von den Driesch, A. 1976. A guide to the measurement of animal bones from archaeological sites. Bull. Peabody Mus., 1. Harvard. Manuscript accepted for publication 7 September, 1977 British Museum (Natural History)Monographs & Handbooks The Museum publishes some 10-12 new titles each year on subjectsincluding zoology, botany, palaeontology and mineralogy.Besides being important reference works, many, particularly amongthe handbooks, are useful for courses and students' backgroundreading. Lists are available free on request to : Publications Sales British Museum (Natural History) Cromwell Road London SW7 5BD Standing orders placed by educational institutions earn a discountof 10% of! our published price. Titles to be published in Volume 35 A revision of the 'acaecate' earthworms of the Pheretima group(Megascolecidae: Oligochaeta) : Archipheretima, Metapheretima,Planapheretima, Pleionogaster and Polypheretima. By E. G. Easton, Miscellanea The planktonic copepods of the northeastern Atlantic Ocean:Harpacticoida, Siphonostomatoida and Mormonilloida. By G. A.Boxshall. Towards a phyletic classification of the 'genus' Haplochromis (Pisces,Cichlidae) and related taxa. Part I. By Peter Humphry Greenwood. A revision of the British species of the genus Phthiracarus Perty, 1841(Cryptostigmata : Euptyctima). By B. W. Parry. Type set by John Wright & Sons Ltd, Bristol and Printed by Henry Ling Ltd, Dorchester Bulletin of the British Museum (Natural History) The planktonic copepods of the northeaster]Atlantic Ocean: Harpacticoida,Siphonostomatoida and Mormonilloida G. A. Boxshall Zoology series Vol 35 No 3 26 April 1979 The Bulletin of the British Museum (Natural History), instituted in 1949, is issued in fourscientific series, Botany, Entomology, Geology (incorporating Mineralogy) and Zoology,and an Historical series. Parts are published at irregular intervals as they become ready. Volumes will contain aboutthree hundred pages, and will not necessarily be completed within one calendar year. Subscription orders and enquiries about back issues should be sent to : Publications Sales,British Museum (Natural History), Cromwell Road, London SW7 5BD, England. World List abbreviations: Bull. Br. Mus. nat. Hist. (Zool.) Trustees of the British Museum (Natural History), 1979 ISSN 0007-1498 Zoology series Vol 35 No 3 pp 201-264British Museum (Natural History)Cromwell RoadLondon SW7 5BD Issued 26 April 1979 The planktonic copepods of the northeasternAtlantic Ocean: Harpacticoida, Siphonostomatoidaand Mormonilloida G. A. Boxshall f Department of Zoology, British Museum (Natural History), Cromwell Road, London SW7 5BD Contents Synopsis 201 Introduction . 201 Materials and methods . 202 Key to planktonic species ........... 202 Descriptions of species Harpacticoida 203 Genus Aegis thus ........... 203 Genus Microsetella ........... 207 Genus Bathyidia 209 Genus Volkmannia gen. nov. . . . . . . . . .213 Genus Neotisbella gen. nov. ......... 222 Phylogenetic relationships of the new genera 227 Genus Euterpina ........... 228 Genus Parathalestris ........... 229 Genus Clytemnestra . . . . . . . . . . .231 Genus Miracia 234 Genus Oculosetella ........... 237 Genus Macrosetella . . . . . . . . . . .237 Siphonostomatoida 238 Genus Ratania 238 Genus Pontoeciella ........... 240 Genus Hyalopontius ........... 243 Key to species of Hyalopontius 244 Mormonilloida 255 Genus Mormonilla 256 Species depth distributions 258 Acknowledgements 262 References 262 Synopsis Diagnoses of 17 species of planktonic harpacticoids are given, including two new mesopelagic genera,Volkmannia and Neotisbella, and 3 new species, Volkmannia forficula, V. attenuata and Neotisbella gigas,belonging to the family Tisbidae. The new genera are related to the genus Bathyidia Farran, and the maleof the type species of this genus, B. remota Farran, is described for the first time. Ten species of planktonicsiphonostomatoids are described, including 6 new bathypelagic species belonging to the genus Hyalo-pontius Sars ( Megapontius Hulsemann). The new species are H. hulsemannae, H. alatus, H. spinatus,H. roei, H. cinctus and H. enormis. The 2 species of Mormonilla Giesbrecht are described and the syste-matic position of this aberrant genus is considered. It is proposed to raise the family Mormonillidae to anew order, the Mormonilloida, derived from the podoplean line within the Copepoda. Introduction This revision of the minor planktonic copepod orders occurring in the northeastern Atlanticwas prompted by the discovery of two new genera of planktonic harpacticoids and of six new Bull. Br. Mus. not. Hist. (Zool.) 35 (3) : 201-264 Issued 26 April 1979 201 202 G. A. BOXSHALL species of free-living bathypelagic siphonostomatoids. Good descriptions of the representativesof the minor orders, Harpacticoida, Siphonostomatoida and Mormonilloida, are often notavailable or are not readily accessible to plankton workers who tend to concentrate on the moredominant groups. Consequently, these groups are comparatively poorly studied and publisheddata on occurrence, depth distribution and other aspects of their biology are scarce. Materials and methods This study is based on a day and night series of hauls taken at 'Discovery' station 7089 in theregion of the Cape Verde Islands (18 N 25 W) using the RMT 1 + 8 net system. The details ofhauls and the fractions examined are given in Boxshall (1977). The Hyalopontius material wascaught using the same net system in the northeastern Atlantic at a number of stations fished between1974 and 1977. Dr Howard Roe (I.O.S.) isolated the Hyalopontius material from these lattersamples and kindly allowed me to work them up. The type material of several of the speciesredescribed below and other specimens from important collections were also examined. All thespecimens examined are stored in the British Museum (Natural History) ; a maximum of tenregistration numbers is assigned to any one species-collection. Body lengths were measured fromthe tip of the rostrum to the distal end of the caudal rami excluding the caudal setae, except inAegisthus Giesbrecht. In this genus body length was measured from the base of the rostrum to theproximal end of the very elongate caudal rami. Key to planktonic species belonging to the Harpacticoida, Siphonostomatoidaand Mormonilloida found in the northeastern Atlantic Ocean 1 Leg 5 present ; second antenna exopod at most 4-segmented, sometimes absent . . . 2Leg 5 absent; second antenna exopod 8-segmented .... (MORMONILLOIDA) 21 2 Mandible stylet-like, located within an oral cone, without palp; inner seta present on coxa of legs 1-4 . . (SIPHONOSTOMATOIDA) 18 Mandible not stylet-like, usually with palp; coxal seta absent . . (HARPACTICOIDA) 3 3 First thoracic somite free (prosome 5-segmented) 4 - First thoracic somite fused to cephalothorax (prosome 4-segmented) 5 4 Dorsal surface of prosome without chitinous markings; rostrum absent in <J, long in ?; first antenna 6-segmented in ? . . . . . . . . - . Aegisthus mucronatus Dorsal surface of prosome without chitinous markings; rostrum short in ?; first antenna 7-segmented in ? .......... Aegisthus spinulosus - Dorsal surface of prosome with chitinous markings ; rostrum short in both sexes ; first antenna 7-segmented in both sexes Aegisthus aculeatus 5 Body small, fusiform (Figs 2A, B), without marked boundary between prosome and urosome ; caudal rami short; leg 1 with 3-segmented rami 6 - These characters not combined ........... 7 6 Body length 0-3-0-6 mm; inner caudal seta about 3 times longer than outer caudal seta and usually about as long as body ....... Microsetella norvegica Body length 0-6-0-9 mm; inner caudal seta 7-10 times longer than outer seta and usually morethan 1-5 times longer than body ....... Microsetella rosea 7 Both rami of leg 1 2-segmented Euterpina acutifrons At least one ramus 3-segmented 8 8 Leg 1 exopod 3-segmented; second antenna exopod 4-segmented; second maxilla reduced to basal segment with 1 seta and terminal claw (as Fig. 4F) 9 - These characters not combined ........... 1 2 9 Leg 1 endopod 2-segmented Neotisbella gigas sp. nov. Leg 1 endopod 3-segmented 10 10 Third endopod segment of leg 1 comprising about 14% of length of ramus; mandible endopod with 2 proximal and 5 apical setae Bathyidia remota - Third endopod segment of leg 1 comprising about 3-5% of length of ramus; mandible endopod with 3 proximal and 6 apical setae ........ 1 1 11 Endopod of leg 1 about 34% longer than exopod . . . Volkmanniaforficulasp.nov. - Endopod of leg 1 about 70% longer than exopod . . . Volkmannla attenuata sp. nov. PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 203 12 Maxilliped very squat and robust; leg 1 rami 3 -segmented . . . Parathalestris croni - Maxilliped slender ; one ramus of leg 1 with less than 3 segments . . . . . 13 13 Leg 1 with 3-segmented endopod and 1 -segmented exopod . . . . . . 14 - Leg 1 with 2-segmented endopod and 3-segmented exopod 15 14 First antenna 8-segmented; leg 1 exopod with 4 setae . . . Clytemnestra scutellata - First antenna 7-segmented ; leg 1 exopod with 3 setae .... Clytemnestra rostrata 15 Cephalosome with a pair of large cuticular lenses . . . . . . . . 16 - Cephalosome without cuticular lenses ....... Macrosetella gracilis 16 Exopod of second antenna 1 -segmented with 2 distal setae . . . . . . 17 - Exopod of second antenna absent ........ Oculosetella gracilis 1 7 Baseoendopod of leg 5 with 5 setae in <$, 3 in $ . . . . . Miracia efferata - Baseoendopod of leg 5 with 4 setae in ?, 2 in <J Miracia minor 18 First antenna 11 -segmented in both sexes Hyalopontius (see p. 244) - First antenna 5- to 9-segmented ........... 19 19 Second antenna exopod absent ; leg 5 with free segment ....... 20 - Second antenna exopod 1 -segmented; leg 5 without free segment . Pontoeciella abyssicola 20 First antenna 5-segmented in ?, 7-segmented in <J ...... Rataniaflava - First antenna 7-segmented in ?, 9-segmented in $ . . . . . . Ratania atlantica 21 First antenna 3-segmented; lateral seta of caudal ramus located about 33% of distance along ramus ............ Mormonilla phasma - First antenna 4-segmented; lateral seta of caudal ramus located about 16% of distance along ramus Mormonilla minor Description of speciesHARPACTICOIDA A total of 17 species belonging to 7 families are regarded here as being true planktonic forms.Many other harpacticoids have been recorded from the plankton, but they have usually beenfound in the neritic zone and can be regarded as temporarily displaced littoral forms (Wells,1970). Occasionally littoral species are carried into oceanic waters by clinging to algae driftingin ocean currents (Yeatman, 1962), these can also be regarded as expatriated specimens as theyare not permanent members of the plankton. Family AEGISTHIDAE Genus AEGIS THUS Giesbrecht, 1891 DIAGNOSIS. Prosome 5-segmented with first thoracic somite free and about equal in size to thefollowing somite. Genital complex ($) with dorsal and lateral transverse suture line. Caudal ramiat least twice as long as whole body. Rostrum present or absent. First antenna (?) 6- or 7-seg-mented, (() 7- or 8-segmented, weakly or not geniculate. Second antenna slender with 1 -seg-mented exopod bearing 1 or 2 setae. Mandible (?) with or without rudimentary palp; apparentlyabsent in $. First maxilla ($) well developed, (<) bilobed, rudimentary. Second maxilla (?) welldeveloped, (<J) with well-developed basipod but rudimentary rami. Maxilliped 3-segmented; ($)well developed, ($) poorly developed. Legs 1-4 with 3-segmented rami, armature formula asfollows : Coxa Basis Endopod Exopod Leg 1 0-0 1-1 0-1 ; 0-1 ; 1, 2, 2 1-1 ; 1-1 ; I, 2, 2 Leg 2 0-0 1-0 0-1 ; 0-2; 1, 2, 2 1-1 ; 1-1 ; III, 2, 2 Leg 3 0-0 1-0 0-1 ; 0-2; 1, 2, 3 1-1 ; 1-1 ; III, 2, 2 Leg 4 0-0 1-0 0-1; 0-1; 1,2, 2 1-1 ; 1-1 ; III, 2, 3 Leg 5 elongate, bearing a short naked seta and 5 serrate setae ($) and with 5 serrate setae and 2additional plumose setae in <J. Leg 6 with 1 or 2 small setae. 204 G. A. BOXSHALL TYPE-SPECIES. Aegisthus mucronatus Giesbrecht, 1891. REMARKS. Some differences of opinion exist over the homology of the caudal rami in this well-defined genus. Giesbrecht (1892), Scott (1894), Farran (1905), Rose (1933) and Wells (1970) haveerroneously interpreted the structures on the anal somite as comprising very short caudal ramifused to the anal somite and each bearing an extremely long seta which is itself setate (see Scott,1894; pi. 11, figs 31 & 44). In fact the caudal rami are extremely long (often as much as five timeslonger than the body), closely pressed together and armed with a lateral seta in the middle thirdof each ramus and at least 2 apical setae, one of which is plumose (Sars, 1916; Lang, 1948). Aegisthus mucronatus Giesbrecht, 1891 Aegisthus mucronatus Giesbrecht, 1891 : 476. A. longirostris Scott, 1894 : 104, pi. XI, figs 31^4. A. dubius Sars, 1916 : 8, 14, pi. VIII. DIAGNOSIS. Female. Prosome without reticulate chitinous markings on dorsal surface ; maximumbody width at level of second free thoracic somite (Fig. 1A). Genital complex with dorsal andlateral transverse suture line, armed with spinules. Rostrum very long and anteriorly directed.First antenna 6-segmented with large hook-like process medially on proximal segment. Secondantenna with 2 unequal distal setae on exopod. Maxilliped (Fig. IB) 3-segmented with 3 enlargedspines and 1 seta on middle segment and 3 setae on distal segment. Leg 1 with 3-segmented rami,but suture lines between segments 2 and 3 sometimes indistinct; exopod segments 2 and 3 withshort spines on outer margins. Leg 5 (Fig. 1C) free segment with 3 serrate setae on lateral margin,1 serrate seta and a naked seta distally and 1 serrate seta subapically. Leg 6 (Fig. ID) an elongatefree segment with a short subapical and a long apical seta. Body length of female from 1-90 to 2-55 mm. Male. As $ except: cephalothorax (Fig. IE) relatively narrow. Rostrum absent. First antenna8-segmented. Second antenna (Fig. IF) with 1 seta distally on exopod. First maxilla bilobed,rudimentary. Second maxilla with large claw-like process on basipod, rami rudimentary with 5short setae. Maxilliped 3-segmented; weakly developed, carrying 2 short setae on apex of distalsegment. Leg 5 (Fig. 1G) 2-segmented; first segment with small proximal seta and distal serrateseta on outer margin; second segment with 2 serrate seta on outer margin, 2 on distal margin(the inner just longer than the outer) and 2 plumose setae on inner margin. Body length of male from 1-10 to 1-70 mm. MATERIAL EXAMINED. 352 $$, 48 <&?: N.E. Atlantic Ocean, 18 N 25 W, 'Discovery' Stn 7089.BM(NH) registration numbers 1977.155-164 ($) and 1977.165-174 ($). 3 $$, 1 <? syntypes of A.longirostris: Gulf of Guinea, 1 55' N 5 55' E (Scott, 1894). BM(NH) registration numbers1893.4.22.588-589. REMARKS. Sars (1916) described A. dubius from male specimens and mentioned the similaritiesbetween it and female A. mucronatus. He regarded it as a separate species because of the absenceof a rostrum, the structure of the first antenna and the marked reduction of the mouthparts.Farran (1926) suspected that A. dubius was the male of A. mucronatus, as A. mucronatus femaleswere found in every haul from which A. dubius was recorded but he did not synonymize the twospecies because Scott (1894) had described both sexes of a new species, A. longirostris, the femalesof which had since been recognized as being synonymous with A. mucronatus. The syntype seriesof A. longirostris contains only 1 male specimen. This specimen lacks a rostrum and its append-ages are as described by Sars (1916) for A. dubius. The arostrate males (A. dubius Sars, 1916)have been correctly regarded as the males of A. mucronatus by most authors since Lang (1948). Aegisthus aculeatus Giesbrecht, 1891 DIAGNOSIS. Female. Cephalothorax and free thoracic somites with conspicuous reticulate markings(Fig. 1H); maximum width of body near mid-point of cephalothorax. Genital complex subdivided PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 205 Fig. 1 Aegisthus mucronatus: A, female; B, maxilliped; C, fifth leg; D, sixth leg; E, male; F,second antenna; G, fifth leg. A. aculeatits: H, female; I, second antenna; J, maxilliped; K, firstleg; L, fifth leg; M, sixth leg; N, male; O, fifth leg. A. spinulosus: P, female; Q, maxilliped; R, tipof fifth leg. (P-R redrawn from Farran, 1905.) Scales 0-1 mm unless otherwise indicated. 206 G. A. BOXSHALL dorsally and laterally by suture line. First antenna 7-segmented with small prominence mediallyon proximal segment. Second antenna (Fig. II) with 2 distal setae on exopod. Maxilliped (Fig. U)3-segmented, bearing 3 enlarged spines and 2 slender setae on middle segment and 3 setae ondistal segment. Leg 1 (Fig. IK) with 3-segmented rami, exopod segments 2 and 3 with long spineson outer margin. Leg 5 (Fig. 1L) free segment with 3 serrate setae on outer margin and a shortnaked seta and 2 serrate setae on the distal margin ; distal serrate seta on lateral margin 83 % aslong as middle serrate seta on lateral margin; inner apical seta 35-40% longer than outer. Leg 6(Fig. 1M) an elongate free segment with a single long seta and a minute spinule apically. Body length of female from 1-64 to 1-85 mm. Male. As for $ except: prosome more squat in appearance (Fig. IN); second free thoracicsomite as wide as cephalothorax. First antenna 7-segmented. First maxilla bilobed, rudimentary.Second maxilla with well-developed basipod, claw-like process on basipod less curved than in $A. mucronatus, rami rudimentary bearing 1 small and 5 long setae. Maxilliped 3-segmented,slender, with 2 setules on middle segment and 3 setae on distal segment. Leg 5 (Fig. 10) with arma-ture elements as in <$ A. mucronatus but inner distal margin seta about 35-40% longer than outer.Leg 6 with 2 long setae. Body length of male from 1-28 to 1-35 mm. MATERIAL EXAMINED. 154 ?$, 7 <?<: N.E. Atlantic Ocean, 18 N 25 W, 'Discovery' Stn 7089.BM(NH) registration numbers 1977.175-184 (?) and 1977.185-191 (). REMARKS. The male of A. aculeatus has only recently been discovered and partially described(Owre and Foyo, 1967). The mouthparts in male Aegisthus are reduced and are often difficult toobserve. No structure was found in either A. aculeatus or A. mucronatus which could be positivelyidentified as representing the mandible. The first maxilla was represented by a bilobed structurein males of both species ; the larger lobe bearing 5 or 6 setae and the smaller 1 or 2. The secondmaxilla has a well-developed basipod and distal claw but the rami are reduced. The maxillipedis 3-segmented in both species. In A. aculeatus males the middle segment bears 2 setules and thedistal segment 2 naked medial setae and a plumose apical seta. Reduction of this appendagehas proceeded further in male A. mucronatus with the armature comprising only 2 small setae onthe distal segment. The second maxillae and maxillipeds are better developed and closer to thefemale condition in A. aculeatus males than in A. mucronatus males. Aegisthus spinulosus Farran, 1905 DIAGNOSIS. Female. Cephalothorax and free thoracic somites without chitinous reticulations(Fig. IP); maximum width of body anterior to mid-point of cephalothorax. Rostrum short.Genital complex completely subdivided by suture line. First antenna 7-segmented. Second antennaand both maxillae as in A. aculeatus. Maxilliped (Fig. 1Q) 3-segmented, armed with 3 enlargedspines and 4 setae on middle segment and 4 setae on distal segment. Leg 1 with 3-segmented rami;exopod segments 2 and 3 with long spines on outer margins. Leg 5 (Fig. 1R) as in A. aculeatusexcept distal serrate seta on lateral margin only 57% as long as middle serrate seta on lateralmargin. Leg 6 with 2 equal terminal setae.Body length of holotype $ 1-74 mm. MATERIAL EXAMINED. None. REMARKS. In the original description of A. spinulosus Farran (1905) commented on its closeaffinity to A. aculeatus, but listed certain important characters which serve to distinguish betweenthem. The significant differences are the absence of chitinous reticulations from the cephalothorax,the complete subdivision of the genital complex, the armature of the maxilliped (called the firstmaxillipede by Farran) and the sixth leg. If Farran's (1905) description is accurate A. spinulosusshould be regarded as a valid species and not, as suggested by Lang (1948), as a possible lastcopepodid stage of A. aculeatus. PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 207 Family ECTINOSOMATIDAE Genus MICROSETELLA Brady and Robertson, 1873 DIAGNOSIS. Body fusiform, without marked boundary between prosome and urosome; prosome4-segmented with first thoracic somite fused to head, urosome 5-segmented. Rostrum very short,ventrally directed. Caudal rami short, each with a long apical seta. First antenna 6-segmented(Fig. 2C), with an aesthete on segment 3 or 4 and one on segment 6. Second antenna (Fig. 2D)with unarmed basis; exopod 3-segmented with single short seta on segment 1 and 2 long terminalsetae. Mandible (Fig. 2E) blade with few weak teeth; palp well developed, exopod small with fewsetae, endopod large bearing several setae and a large unilaterally pinnate process (seta ?) withan apical seta. First and second maxillae (Figs 2F, G) small. Maxilliped (Fig. 2H) 3-segmented,robust. Legs 1-4 with 3-segmented rami, armature formula: Coxa Basis Endopod Exopod Leg 1 0-0 1-0 0-1; 0-1; I, 2, 2 1-0; 1-1; II, 2, 1 Leg 20-01-0 0-1 ; 0-1 ; I, 2, 2 1-1 ; 1-1 ; II, 2, 2 Leg 3 0-0 1-0 0-1; 0-1; I, 2, 2 1-1 ; 1-1 ; II, 2, 3 Leg 4 0-0 1-0 0-1; 0-1; I, 2,2 1-1 ; 1-1 ; II, 2, 3 Leg 5 with baseoendopod and 1 -segmented exopod; exopod bearing 1 ventral surface seta andeither 3 ($) or 2 (<$) marginal setae. TYPE SPECIES. Microsetella norvegica (Boeck, 1864) (as M. atlantica Brady and Robertson, 1873). Microsetella norvegica (Boeck, 1864) Setella norvegica Boeck, 1864 : 281. Microsetella atlantica Brady and Robertson, 1873 : 130, pi. IX, figs 11-16. Ectinosoma atlanticum Brady, 1880: 13, pi. 38, figs 11-19. DIAGNOSIS. Longest seta (inner seta on distal margin) of caudal ramus usually about as long asbody, sometimes up to 1-5 times longer than body (Figs 2A, B); the second longest seta (outerseta on distal margin) about 33 % as long as the longest caudal seta and between 0-3 and 0-5 timesas long as body. Inner seta on baseoendopod of leg 5 (?) less than half as long as outer seta(Fig. 21). Lateral seta on distal margin of leg 5 exopod (<) apparently naked (Fig. 2J).Body length of female 0-35-0-57 mm; body length of male 0-33-0-42 mm. MATERIAL EXAMINED. 2 $?: N.E. Atlantic Ocean, 18 N 25 W, 'Discovery' Stn 7089. BM(NH)registration numbers 1977.192-193. 1 $: as Ectinosoma atlanticum, Faroe Channel. BM(NH)registration numbers 1901.9.27.101-2. 1 ?, 1 $: Suez Canal Expedition (Gurney, 1927). BM(NH)registration number 1928.4.2.137. 5 ?$: as E. atlanticum, Loch Fyne. BM(NH) registrationnumbers 1956.9.25.45. 12 $$: North Sea off Whitby. BM(NH) registration numbers 1976.653-662. REMARKS. This small species is usually distinguished from the only other species of the genus,M. rosea (Dana, 1848), by the relative length of the body and the longest seta on the caudal ramus.This seta is often shorter than or about as long as the whole body (Lang, 1948; Owre & Foyo,1967; Wells, 1970). However, in the material examined during the present study the length of thelongest caudal seta was found to vary from 20 % less than body length to 44 % more than bodylength (Table 1). More reliable characters which could be used to separate the species are bodysize, the armature of the baseoendopod in the female leg 5 and the relative length of the secondlongest (outer seta on distal margin) caudal seta. This outer caudal seta is about one third (33 %)as long as the inner caudal seta in M. norvegica. 208 G. A. BOXSHALL Fig. 2 Microsetella norvegica: A, female, lateral; B, female, dorsal; C, first antenna; D, secondantenna; E, mandible; F, first maxilla; G, second maxilla; H, maxilliped; I, fifth leg; J, malefifth leg. M. rosea: K, male; L, fifth leg; M, female; N, fifth leg. Scales 0-1 mm unless otherwiseindicated. PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 209 Table 1 Body and caudal seta lengths of examined specimens of Microsetella Microsetella rosea (Dana, 1848)Harpacticus rosea Dana, 1848: 153.Microsetella rosea Giesbrecht, 1891 : 476. DIAGNOSIS. Longest seta (inner seta on distal margin) of caudal ramus from 1-5 to 2 times as longas body (Figs 2K, M); second longest seta (outer seta on distal margin) about 10-15 % as long aslongest caudal seta and between 0-20 and 0-25 times as long as the body. Inner seta on baseo-endopod of leg 5 (?) about the same length as outer seta (Fig. 2N). Lateral seta on distal marginof leg 5 exopod (<J) bilaterally spinulate (Fig. 2L). Body length of female 0-64-0-85 mm; bodylength of male 0-6-0-7 mm. MATERIAL EXAMINED. 2$$: as M. atlanticum. Gulf of Guinea (Scott, 1894). BM(NH) registrationnumbers 1893.4.22.219-223. 1 <j>: as M. atlanticum. Hyeres. BM(NH) registration number1951.11.24.35. 1 <$: off Co. Mayo (Farran, 1908). BM(NH) registration number 1911.11.8.42881. REMARKS. Both sexes of M. rosea are much larger than in M. norvegica. Other characters whichcan be used to separate the species are the relative lengths of the two main caudal setae, the ratioof caudal seta length to body length (see Table 1) and the armature of the baseoendopod of the(?) leg 5. Family TISBIDAEGenus BATHYIDIA Farran, 1926 DIAGNOSIS. Body not laterally compressed (Fig. 4A). Prosome 4-segmented, urosome 5-segmentedin $, 6-segmented in <$. Dorsal surface of prosome and whole surface of urosome more or less 210 G. A. BOXSHALL Fig. 3 Bathyidia remota, holotype female: A, first antenna; B, second antenna; C, urosome; D,mandible 'palp'; E, first maxilla; F, second maxilla; G, maxilliped; H, first leg; I, middle setae ofthird endopod segments from both first legs. Scales 0-1 mm. PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 211 Fig. 4 Bathyidia remota male: A, dorsal; B, first antenna; C, second antenna; D, mandible; E,first maxilla; F, second maxilla; G, maxilliped; H, fifth leg. Scales 0-1 mm unless otherwiseindicated. 212 G. A. BOXSHALL covered with minute denticles. Genital complex ($) subdivided by a dorsal and dorso-lateralsuture line. Genital area probably with 3 short setae either side of oviduct openings (only 2 setaeremaining in holotype $). Caudal rami more than twice as long as wide; with 2 lateral, 1 dorsaland 4 distal setae plus 2 additional elements on the distal margin. First antenna 8-segmented (?) with aesthete on segment 4; 9-segmented (<$) with aesthete onsegment 5, geniculate between segments 7 and 8. Second antenna (Figs 3B, 4C) with 1 seta onbasis; 2-segmented endopod, distal segment with 3 lateral and 7 terminal elements; 4-segmentedexopod with segment 1 bearing 2 setae, segments 2 and 3 bearing 1 seta each and the distal seg-ment with 3 setae. Mandible (Figs 3D, 4D) with unarmed basis and 1 -segmented rami; endopodwith 2 proximal setae on medial margin and 5 apical setae; exopod with 1 medial and 2 apicalsetae. First maxilla (Figs 3E, 4E) inner lobe (arthrite) armed with 1 1 elements, outer lobe includingrudimentary rami bearing 10 elements. Second maxilla (Figs 3F, 4F) with 1 seta on basal segment,claw elongate bearing a spiniform seta and a distal row of pinnules. Maxilliped (Figs 3G, 4G)comprising 3-segments and a terminal claw; middle segment with 3 rows of setules, distal segmentwith 2 setae; displaying dimorphism with the distal segment bearing a strong chitinous processhie?. Legs 1-4 with 3-segmented rami; armature formula as follows: Coxa Basis Endopod Exopod Leg 1 0-0 1-1 0-1; 0-1; 3 1-0; 1-1; 6 Leg 2 0-0 1-0 0-1 ; 0-2; I, 2, 2 1-1 ; 1-1 ; III, I, 3 Leg 3 0-0 1-0 0-1; 0-2; I, 2, 3 1-1 ; 1-1 ; III, I, 4 Leg 4 0-0 1-0 0-1; 0-2; I, 2, 2 1-1; 1-1; III, I, 4 Leg 1 endopod 20-25 % longer than exopod ; basis with spinulate lobe between bases of rami ;inner spine on basis setiform; spines on outer margins of exopod segments 1 and 2 also setiform.Leg 2 displaying sexual dimorphism in structure of inner seta on (^) endopod segment 1. Legs1-4 with minute denticles on surface, especially on lateral surface of coxa and on both anteriorand posterior surfaces of rami; also spinule rows present on posterior surfaces of endopod seg-ments 2 and 3. Leg 5 with small baseoendopod and elongate free segment; baseoendopod with outer plumoseseta and single inner seta; armature of free segment consisting of 1 distal seta on inner and outermargins and 2 setae and a tiny setule around apex. Leg 6 represented by 3 naked setae in <$. TYPE-SPECIES. Bathyidia remota Farran, 1926. REMARKS. The genus Bathyidia was established by Farran (1926) to include a new bathypelagicspecies from the Bay of Biscay, B. remota. Farran's (1926) description of B. remota was incom-plete. The generic diagnosis given here is based on re-examination of the holotype of B. remotaand on the examination of two male specimens. Bathyidia is related to both Tisbe Lilljeborg, 1853and Paraidya Sewell, 1940, as well as to the two new genera described below Neotisbella gen. nov.and Volkmannia gen. nov. The principal distinguishing characters of these five genera and thegenera Tisbella Gurney 1927 and Tisbintra Sewell, 1940 are presented in Table 2. Bathyidia canreadily be distinguished from Paraidya by the segmentation of the first antenna, and from Neotis-bella and Tisbella by the segmentation of the endopod of leg 1 . The differences between Bathyidia,Tisbe and Volkmannia are the armature of the mandibular palp, the relative size of the endopodsegments of leg 1, the armature elements of both rami of leg 1, plus the structure and armatureof the caudal rami. Bathyidia remota Farran, 1926 Bathyidia remota Farran, 1926: 299-300, pi. 10, figs 13-17.Tisbe remota Lang, 1948 : 383, pi. 168, fig. 6. DIAGNOSIS. Prosome of? incompletely known, $ cephalothorax slightly indented laterally (Fig. 4A).Genital complex (?) and urosome somites 3, 4, 5 and 6 (in 3) provided with ventral and ventro- PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 213 lateral rows of spinules along posterior borders (Figs 3C and 5G). Genital area (?) (Fig. 3C) with2 short naked setae either side of oviduct openings, a third seta was probably present but is missingfrom the holotype ?. Caudal ramus (Figs 3C and 5G) 2-2-2-6 times longer than greatest width;armed with 2 lateral setae in proximal half of ramus (the lateral being 6-6-6-9 times long er thanthe ventro-lateral one), an oblique spinule row on the ventral surface extending distally frombases of the lateral setae, another spinule row proximal to the outer distal angle, a naked seta onthe dorsal surface, a seta at the outer distal angle and one at the inner distal angle, 2 long setaeon the inner portion of the distal margin and 2 elements towards the outer end of the distal margin.The latter 2 elements are flaccid and subdivided giving a forked appearance. Relative lengths of $ first antenna (Fig. 3A) segments 15 : 19 : 15 : 14 : 7 : 9 : 5 : 16. Armatureelements incomplete, first segment with 2 spinule rows. First antenna of $ (Fig. 4B) with seg-mental armature elements as follows: 1-1, 11-14, III-7, IV-2, V-6+1 aesthete, VI-3, VII-2,VIII-2, IX-9. First segment also bearing spinule row. Other cephalic appendages as in genericdiagnosis. Inner spine on basis of leg 1 (Figs 3H, 5A) with small distal pinnules and a few larger onesproximally; exopod segment 3 bearing 6 setiform elements, those on outer margin armed withshorter pinnules than those on distal margin ; relative lengths of endopod segments about 46 : 40 :14; outer element on endopod segment 3 setiform but armed with short pinnules, middle elementa simple long plumose seta (holotype $ exhibits aberrant bifurcated condition on only one memberof leg 1 pair (Figs 3H, I)), inner element a plumose seta similar in length to middle element. Legs 2-4 (Figs 5B-F) ; exopod segment 3 with central patch of larger denticles on posteriorsurface (Fig. 5E); endopod segments 2 and 3 with some denticles and about 5 and 16 spinulesrespectively on their posterior surfaces (Fig. 5F). Leg 2 displaying sexual dimorphism with innerseta on endopod segment 1 armed with distal row of spinules (Fig. 5B). Leg 5 of $ (Fig. 3C) with incomplete armature in holotype but traces of absent setae indicatearmature similar to <. Leg 5 of ^ (Fig. 4H) with single inner seta on baseoendopod about as longas free segment: free segment about 2-9 times longer than wide, its ventral surface covered withminute denticles and lateral surface with long spinules; bearing a plumose seta at distal end ofexpanded lateral margin ; projecting distal margin with a tiny setule laterally and 2 long sparselyplumose setae apically; inner margin with single pinnate seta distally. Leg 6 of $ (Fig. 5G) comprising 3 long naked setae situated laterally on genital lobes of urosomesomite 2. Body length of holotype $ 1-48 mm and ^ 1-41 mm. MATERIAL EXAMINED. Holotype $: Bay of Biscay (Farran, 1926). BM(NH) registration number1926.12.6.41. 1 (J: Sargasso Sea, Stn S (Deevey and Brooks, 1977). Florida State Museumcollections. 1 <$: N.E. Atlantic Ocean 18 N 25 W 'Discovery' Stn 7089. BM(NH) registrationnumber 1977.225. REMARKS. The males here assigned to B. remota agree closely with the holotype $ in the charac-teristic structure and armature of the leg 1 . The bifurcate nature of the middle seta on endopodsegment 3 in the holotype is regarded as aberrant because the middle seta on the other member ofthe leg 1 pair, although broken, displays no trace of a bifurcation at the same position on the seta(see Fig. 31). The mouthparts are generally very similar in the males and the female. The malemaxilliped differs from the female in the structure of the third segment, but the male maxillipedsof Neotisbella gigas gen. et sp. nov. and Volkmannia forficula gen. et sp. nov. also exhibit thischaracter whereas their respective females do not. The 2 male specimens are almost identical to the female in the detailed armature of theircaudal rami ; in the position of the spinule rows and especially in the relative lengths of the twolateral setae. These and other similarities strongly suggest that the two males are conspecific withthe holotype $ of B. remota. Genus VOLKMANNIA gen. nov.DIAGNOSIS. Prosome 4-segmented, urosome 5-segmented in $ and 6-segmented in <$. Dorsal 214 G. A. BOXSHALL Table 2 A comparison between the seven genera of the Tisbe group Character Paraidya Tisbella* Tisbintra\ Second antenna Mandible MaxillipedLegl 1 seta on basis; Exp3- or 4-segmented,with 1, 0, 3 or 1, 1, 2,3 elements Basis unarmed, Enpwith 3 medial & 6distal setae, Expwith 2 setae Not exhibitingmarked sexualdimorphism 3-segmented Enp lessthan 10% longer thanExp; Enp seg. 3 with1 outer spine & 2inner setae. Expelements withoutcombs of setules 1 seta on basis; Exp4-segmented with 1,1,1, 3 elements; segs 2 & 3 fused to seg. 4in T. pulchella Basis unarmed, Enpwith 3 medial & 7distal setae, Expwith 2 setae Not exhibitingmarked sexualdimorphism 2-segmented Enp; Enpseg. 2 with 1 outerspine, 2 distal setae& 1 inner seta. Expelements withoutcombs of setules 1 seta on basis; Exp2-segmented (segs 2, 3 &4 fused) with 1, 2proximal & 3 distalelements Basis with 1 small seta,Enp with 3 disto-medial& 5 or 6 distal setae,Exp with 2 setae Not exhibitingmarked sexualdimorphism 2-segmented Enp, about60 % longer than Exp ;Enp seg. 2 with 1 innerseta & 1 or 2 distalelements. Exp elementswithout combs ofsetules Leg5 Free segment with3 or 4 setae Free segment with5 plumose setae Free segment with4 or 5 setae Caudal ramus Less than 2'5 timeslonger than wide;with 6 elementsincluding 1 lateralseta in distal halfof ramus As wide as long orjust longer than wide;with 7 elementsincluding 1 lateralseta in distal halfof ramus Shorter than wide;with 6 elementsincluding 1 lateralseta in distal halfof ramus * Data from Yeatman (1963) and from re-examination of holotype ? of Tisbella timsae Gurney, 1927 from ImasiluSuez canal: BM(NH) registration number 1928.4.2.51. t Data from Sewell (1940) and from examination of 2 ?? & 2 <$<$ specimens of Tisbintra jonesi Ummerkutty, 196from Kuwait: BM(NH) registration numbers 1975.1201-1210. surface of prosome and whole surface of urosome more or less covered with minute denticles.Rostrum small. Genital complex (9) markedly subdivided by dorsal and dorso-lateral suture line,suture line absent ventrally; genital area with 1 short outer seta and 2 long naked setae either sideof oviduct openings. Caudal rami about twice as long as wide, with 2 lateral, 1 dorsal and 4 distalsetae plus 2 additional elements on the distal margin. First antenna 8-segmented (?) with aesthete on segment 4; 9-segmented (<) with aesthete onsegment 5, geniculate between segments 7 and 8. Second antenna with 1 seta on basis; 2-seg- PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 215 mented endopod with distal segment bearing 3 lateral and 7 terminal elements; 4-segmentedexopod with 2 setae on segment 1, 1 seta each on segments 2 and 3 and 3 setae on the distal seg-ment. Mandible with unarmed basis and 1 -segmented rami; endopod with 3 proximal setae onmedial margin and 6 apical setae ; exopod with 1 medial margin and 2 apical setae. First maxillainner lobe armed with 9 elements, outer lobe with 1 1 elements. Second maxilla with 1 seta onbasal segment, claw elongate with 1 plumose seta, a proximal curved row of tiny spinules and adistal row of pinnules. Maxilliped 3-segmented and with a terminal claw; middle segment with 216 G. A. BOXSHALLB Fig. 5 Bathyidia remota male: A, first leg, anterior; B, second leg; C, third leg; D, fourth leg;E, third exopod segment of fourth leg, posterior; F, second and third endopod segments of fourthleg, posterior; G, urosome. Scales 0-1 mm. setule rows, distal segment with 2 setae; displaying sexual dimorphism with distal segmentbearing strong chitinous process in <$.Legs 1-4 with 3-segmented rami; armature formula as follows: Coxa Basis EndopodLegl 0-0 1-1 0-1; 0-1; 1, 2Leg 2 0-0 1-0 0-1; 0-2; I, 2, 2Leg 3 0-0 1-0 0-1; 0-2; 1,2,3Leg 4 0-0 1-0 0-1; 0-2; 1,2,2 Exopod1-0; I-!1-1; 1-1 6 III, I, 31-1; 1-1; 111,1,41-1; 1-1; 111,1,4 PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 217 Leg 1 endopod about 25-30% longer than exopod; inner spine on basis stout and spinulate;spine on outer margin of exopod segment 1 strongly developed, that on segment 2 setiform;endopod segment 3 very small bearing an outer spine, a distal seta and a small inner seta. Leg 2displaying sexual dimorphism in armature of inner seta of endopod segment 1 . Legs 1-4 withvery minute denticles on surfaces of coxa, basis and rami; also spinule rows present on posteriorsurfaces of endopod segments 2 and 3 of legs 2-4. Leg 5 with small baseoendopod and elongate free segment, ventral surface of latter coveredwith minute denticles; baseoendopod with outer plumose seta and 3 inner setae in $ or 1 in <$;free segment expanded laterally with short spinules along outer margin; armature comprising 1lateral seta positioned at apex of lateral expansion, 1 distal seta on inner margin and 2 plumosesetae and a small naked seta around apex. Leg 6 represented by 3 long plumose setae in $. TYPE-SPECIES. Volkmannia forficula sp. nov. ETYMOLOGY. This genus is named after Dr Brigitte Volkmann in recognition of her work on thegenus Tisbe. REMARKS. The new genus can be distinguished from Paraidya, Bathyidia, Tisbella, Neotisbellagen. nov. and Tisbintra by the segmentation of the leg 1 and the armature of the mandibularpalp. Although there is a close superficial resemblance between Volkmannia and Tisbe there aresignificant differences in the mandible, leg 1 and caudal rami. The mandible of Tisbe possesses atleast one seta on the basis whereas the mandible of Volkmannia has an unarmed basis. The distalsegment of the leg 1 endopod in Tisbe usually possesses only 2 (occasionally 3) armature elementsat least one of which is armed with a distal comb of long setules ; similar combs are also found onthe outer margin elements of exopod segments 2 and 3 in Tisbe species. The distal segment of leg 1endopod possesses 3 armed elements in Volkmannia species, and none of the elements on eitherramus is armed with a distal comb of setules. The caudal ramus of Volkmannia closely resemblesthat found in Bathyidia and Neotisbella, but differs greatly in both structure and armature fromthat found in Tisbe. Volkmannia forficula sp. nov. DIAGNOSIS. Prosome rounded, maximum body width about mid-point of prosome (Figs 6A, 8D).Genital complex ($) and urosome somites 3, 4, 5 and 6 (in <$) provided with ventral and lateralrows of spinules along posterior borders. Genital area (?) (Fig. 6F) with a short outer plumoseseta and 2 subequal long inner naked setae. Caudal ramus (Fig. 6D) about 2-6 times longer thangreatest width; armed with 2 lateral setae in proximal half of ramus (the lateral being about 1-9times longer than the ventro-lateral one), an oblique spinule row extending from near base oflateral seta, another spinule row around outer distal angle, a naked seta on dorsal surface, aseta at the outer distal angle and 1 at the inner distal angle, 2 long plumose setae on the innerportion of the distal margin and 2 elements in the middle of the distal margin. The latter 2 ele-ments are thin walled and flaccid. Relative lengths of $ first antenna segments 14:18:20:16:5:8:3:16 (Fig. 7 A); armatureelements as follows; segment 1-1, 11-14, III-7, IV-4+1 aesthete, V-0, VI-4, VII-1, VIII-5;segment I also bearing 2 rows of spinules. First antenna ($) armature as follows; segment 1-1,11-11, III-4, IV-2, V-6 + 1, aesthete VI-2, VII-2, VIII-2, IX-11 (Fig. 8E); segment I also bearing2 spinule rows. Other cephalic appendages as in generic diagnosis (p. 213). Maxilliped terminal claw with single spinule on concave margin in both sexes (Figs 6E, 8F). Leg 1 provided with extremely minute denticles on its surface (as in Bathyidia and Neotisbellabut too small to be accurately figured); inner spine on basis strongly developed, much shorterthan endopod segment 1 and armed with long pinnules proximally and short pinnules distally(Fig. 7D). Outer margin of exopod segment 1 with well-developed spine, slightly swollen proxi-mally; outer margins of exopod segments 2 and 3 bearing setiform elements armed with short 218 G. A. BOXSHALL Fig. 6 Volkmanniaforficula n. sp.: A, female; B, second antenna; C, first maxilla; D, caudalramus; E, maxilliped; F, genital area. Scales 0-1 mm unless otherwise indicated. pinnules. Endopod about 34 % longer than exopod, relative lengths of endopod segments 56 :39 : 5; outer element on endopod segment 3 setiform and sparsely provided with short spinules;middle element forked at tip in both sexes (Fig. 7E) and very sparsely pinnate, inner element ashort and very slender naked seta. Legs 2-4 (Figs 8A-C, G) provided with extremely minute denticles on their surfaces as in leg 1 ;exopod segment 3 with central patch of larger denticles on posterior surface ; endopod segments2 and 3 with some very minute denticles and about 5 and 12-16 spinules respectively on theirposterior surfaces (Figs 8A, B). Leg 2 displaying sexual dimorphism, with inner seta on endopodsegment 1 armed with an additional row of spinules distally in $ (Fig. 8G). Leg 5 $ (Fig. 7F) with endopod represented by 3 setae on baseoendopod, a medium lengthinner seta with small pinnules, a long middle seta with small pinnules and a small outer nakedseta; free segment expanded laterally, about 2-5 times longer than wide; ventral surface coveredwith irregularly arranged denticles of varying size and bearing a row of short spinules laterally;armature elements comprising 1 medium length plumose seta at the distal angle of the lateral PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 219 Fig. 7 Volkmannia forficula n. sp.: A, female first antenna; B, mandible; C, second maxilla;D, first leg; E, tip of apical seta of third endopod segment of first leg; F, fifth leg. Scales 0-1 mmunless otherwise indicated. expansion, 1 minutely pinnate long seta at the inner distal angle, 2 long distal setae, the innerminutely pinnate and the outer plumose, and a short naked seta positioned between them andthe lateral seta. Leg 5 (<) as for female except only a single short and minutely pinnate seta presenton baseoendopod (Fig. 8H); free segment about 2-3 times longer than greatest width, armatureelements similar except the lateral plumose seta is relatively longer than in female. Leg 6 (<) comprising 1 medium length sparsely pinnate inner seta and 2 similar but longerouter setae positioned laterally on genital lobes of urosome somite 2 (Fig. 81). Body length of $$ from 1-22 to 1-63 mm and $$ from 1-04 to 1-18 mm. MATERIAL EXAMINED. Holotype ?, 2 &? and 6 $? paratypes: N.E. Atlantic Ocean 18 N 25 W,'Discovery' Stn 7089. BM(NH) registration numbers 1977.233 (holotype), 1977.234-5 (&) and1977.236-241 (??). 220 G. A. BOXSHALL Fig. 8 Volkmannia forficula n. sp.: A, female second leg, posterior; B, third leg; C, endopod offourth leg, anterior; D, male; E, first antenna; F, maxilliped; G, endopod of second leg, anterior;H, fifth leg; I, sixth leg. Scales 0-1 mm unless otherwise indicated. REMARKS. The general similarity between the males and females described above and the presenceof very distinctive characters in both sexes, such as the forked middle seta on the apex of leg 1endopod, indicate that they are conspecific. Sexual dimorphism was noted in the third maxillipedsegment, as in Bathyidia and Neotisbella, and in the setation of the baseoendopod of leg 5, as inNeotisbella. Volkmannia attenuata sp. nov. DIAGNOSIS. Prosome very broad (possibly due to distortion), maximum body width about mid-point of prosome (Fig. 9 A). Genital complex and urosome somites 3, 4 and 5 provided with spinule PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 221 Fig. 9 Volkmannia attenuata n. sp., holotype female: A, dorsal; B, caudal ramus; C, genitalarea; D, first antenna; E, maxilliped; F, first leg; G, fifth leg. Scales 0-1 mm unless otherwiseindicated. rows all around posterior borders except ventrally on somite 3. Genital area ($) with 3 approxi-mately equal naked setae (Fig. 9C). Caudal ramus (Fig. 9B) about 2 times longer than greatestwidth; armed with 2 lateral setae in proximal half of ramus (the lateral being about 1-7 timeslonger than the ventro-lateral one), an oblique spinule row on the ventral surface extending from 222 G. A. BOXSHALL near base of ventro-lateral seta, some spinules at inner distal angle, a naked seta on dorsal surface,a seta at outer distal angle and 1 at inner distal angle, 2 long plumose setae on inner portion ofdistal margin and 2 elements on outer portion of distal margin. The latter 2 elements are thinwalled and flaccid. Relative lengths of? first antenna segments 13:18:19:15:7:8:5:15 (Fig. 9D); armatureincomplete, elements present as follows: segment 1-1, II-5, III-6, IV-4+1 aesthete, V-0, VI-2,VII-1, VIII-3; segment 1 also bearing a row of spinules. Other cephalic appendages as in generic diagnosis (p. 213). Maxilliped (Fig. 9E) with 5 rows of setules on middle segment; terminal claw with 2 spinuleson concave margin. Leg 1 provided with extremely small surface denticles (too small to be accurately figured);inner spine on basis strongly developed, shorter than endopod segment 1, armed with long pin-nules proximally and short pinnules distally (Fig. 9F). Exopod segment 1 with well-developedouter margin spine and a row of 5 broad spinules on anterior surface; outer margins of exopodsegments 2 and 3 bearing setiform elements armed with short pinnules. Endopod about 70%longer than exopod, relative lengths of endopod segments 47 : 50 : 3 ; outer element on endopodsegment 3 spiniform and unilaterally provided with short pinnules, middle element subdividedat tip and sparsely pinnate, inner element a slender sparsely pinnate seta. Legs 2-4 damaged and incomplete but the armature elements appear to be similar to those ofVolkmannia forficula. Leg 5 (Fig. 9G) with endopod represented by 3 setae on baseoendopod, a small inner seta, along middle seta with small pinnules, and a very small outer naked seta; free segment not markedlyexpanded laterally, about 3-2 times longer than greatest width; ventral surface with irregularlyarranged denticles of varying sizes and a row of short spinules laterally; armature elements com-prising 1 medium length plumose seta at outer distal angle, 1 pinnate seta (broken in holotype) atthe inner distal angle, 2 medium length pinnate setae distally and a short naked seta positionedbetween them and the lateral seta. Body length of holotype $ 1-18 mm. Male unknown. MATERIAL EXAMINED. Holotype ?: N.E. Atlantic Ocean 20 N 21 W, 'Discovery' Stn 9131 18.BM(NH) registration number 1977.324. REMARKS. This species can be distinguished from V. forficula by the elongate endopod of leg 1(from which the specific name is derived) and by the proportions of the leg 5 and caudal rami. Genus NEOTISBELLA gen. nov. DIAGNOSIS. Prosome 4-segmented, large and vaulted; urosome 5-segmented in $ and 6-segmentedin c. Dorsal surface of prosome and whole surface of urosome more or less covered with minutedenticles. Rostrum small. Genital complex ($) subdivided by dorsal and dorso-lateral sutureline; genital area with 1 long plumose outer seta and 2 short naked inner setae either side of ovi-duct openings. Caudal rami more than twice as long as wide, with 2 lateral, 1 dorsal and 4 distalsetae, plus 2 additional elements on the distal margin. First antenna 8-segmented (?) with aesthete on segment 4; 9-segmented (<$) with aesthete onsegment 5, geniculate between segments 7 and 8. Second antenna with unarmed basis; 2-seg-mented endopod, distal segment with 3 lateral and 7 terminal elements; 4-segmented exopod,segments 1 and 3 bearing 1 seta each, segment 2 unarmed and distal segment with 3 seta. Mandiblewith unarmed basis and 1 -segmented rami; endopod with 1 proximal seta on medial margin and4 apical setae; exopod with 1 medial and 2 apical setae. First maxilla inner lobe armed with 10elements, outer lobe bearing 11 elements. Second maxilla with 1 seta on basal segment, clawelongate bearing 1 short plumose seta and a distal row of pinnules. Maxilliped comprising 3segments and a terminal claw; middle segment with 3 rows of setules, distal segment bearing 2setae; displaying sexual dimorphism with the distal segment bearing a strong chitinous process PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 223 Leg 1 with 3-segmented exopod and 2-segmented endopod, legs 2-4 with both rami 3-segmented;armature formula as follows : Coxa Basis Endopod Exopod Leg 1 0-0 1-1 0-1; 1, 2,1 I-0;I-1;6 Leg 2 0-0 1-0 0-1; 0-2; I, 2, 2 1-1 ; 1-1 ; III, I, 3 Leg 3 1-0 1-0 0-1; 0-2; I, 2, 3 1-1 ; 1-1 ; III, I, 4 Leg 4 0-0 1-0 0-1; 0-2; I, 2, 2 1-1 ; 1-1 ; III, I, 4 Leg 1 endopod about 10% longer than exopod; inner spine on basis long and pinnate; spineson outer margins exopod segments 1 and 2 setiform; endopod segment 2 with many slenderspinules laterally and distally. Leg 2 displaying sexual dimorphism in structure of inner seta ofendopod segment 1. Legs 1-4 with minute denticles on surfaces of coxa, basis and rami; alsospinule rows present on posterior surfaces of endopod segments 2 and 3. Leg 5 comprising small baseoendopod and elongate free segment, ventral surfaces of bothcovered irregularly with minute denticles; baseoendopod with outer plumose seta and innerplumose seta; free segment with slender spinules all along lateral and ventro-lateral surfaces, andon middle portion of medial surface ; armature comprising 1 distal seta on both inner and outermargins and 2 plumose setae and a small naked seta around the apex. Leg 6 represented by 1short and 2 long plumose setae in <$. TYPE-SPECIES. Neotisbella gigas sp. nov. ETYMOLOGY. The generic name alludes to the superficial similarity between the new genus andTisbella. REMARKS. The only other genera in the subfamily Tisbinae which possess a 2-segmented endopodon the leg 1 are Tisbella and Tisbintra. The reduction in the number of armature elements on leg 1 endopod serves to separate Tisbintrafrom both Tisbella and the new genus. Some of the significant differences between Tisbella andNeotisbella are tabulated in Table 2. Other differences are the relative size of the endopod segmentsof legs 2-4, and the presence of an outer spine on exopod segment 2 of the leg 1 in Tisbellacompared with the setiform element present in Neotisbella. Neotisbella gigas sp. nov. DIAGNOSIS. Prosome angular and vaulted in appearance (Fig. 10 A); maximum width in anteriorthird of cephalosome (Fig. 12A). Genital complex ($) and urosome somites 3, 4, 5 and 6 (in c)provided with ventral and lateral rows of spinules along posterior borders. Genital area ($)(Fig. 1 1G) with a short inner naked seta, a slightly longer naked middle seta and a long plumoselateral seta. Caudal ramus (Fig. 10F) about 1-9 times longer than greatest width; armed with2 lateral setae in proximal half of ramus (the lateral being about 1-7 times longer than the ventro-lateral one), an oblique spinule row on ventral surface extending from near base of lateral seta, aspinule row just proximal to the distal margin, a naked seta on the dorsal surface, a seta at theouter distal angle and one at the inner distal angle, 2 medium length plumose setae on the innerportion of the distal margin and 2 elements in the middle of the distal margin. The latter 2 ele-ments are thin-walled and bifurcated at different levels. Relative lengths of $ first antenna segments 9 : 19 : 19 : 17 : 9 : 10 : 4 : 13 (Fig. 10B); armatureelements as follows; segment 1-1, 11-13, III-9, IV-3 + 1 aesthete, V-2, VI-5, VII-1, VIII-5; allsegments provided with minute denticles on surfaces and segment I bearing large area of spinules ,segment III about 6 spinules and segment IV 3 irregular rows of spinules. First antenna (<J)armature elements as follows; segment 1-1, 11-15, III-8, IV-2, V-8 + 1 aesthete, VI-2, VII-2,VIII-0 (?), IX-1 1 (Fig. 12B); segment I with 2 spinule rows, segment 7 with several rows of shortspinules on antero-ventral surface (see Fig. 12C). Other cephalic appendages as in generic diagnosis (p. 222). 224 G. A. BOXSHALL Fig. 10 Neotisbella gigas n. sp.: A, female; B, first antenna; C, second antenna; D, mandible; E,maxilliped; F, caudal ramus; G, first leg, anterior. Scales 0-1 mm unless otherwise indicated. Maxilliped terminal claw bearing a row of outer spinules on the convex margin in both sexesand two spinules on concave margin in $ (Fig. 10E); one spinule in $ (Fig. 12D). Inner spine on basis of leg 1 much longer than endopod segment 1 and armed with small pin-nules in $ (Fig. 10G); shorter than segment 1 and apparently naked in $ (Fig. 12E). Armatureelements on outer margins of exopod segments all setiform, those on segments 1 and 2 and the 3proximal elements on segment 3 with shorter pinules than those on distal margin of segment 3 ;outer element on endopod segment 2 setiform but armed with shorter pinnules than the outer PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 225 Fig. 11 Neotisbella gigas n. sp. : A, second leg, anterior; B, third leg; C, fourth leg; D, first maxilla;E, second maxilla; F, fifth leg; G, genital area; H, male endopod of second leg, posterior. ScalesOl mm. two distal plumose setae; endopod segments 1 and 2 both with long spinules on lateral and disto-medial surfaces. Legs 2-4 (Figs 11A-C); exopod segment 3 bearing central patch of larger denticles on posteriorsurface; endopod segments 2 and 3 armed with some denticles and about 7 and 16 spinulesrespectively on their posterior surfaces (Fig. 11H). Leg 2 displaying sexual dimorphism, the innerseta on endopod segment 1 stout and spiniform, and armed with distal row of stout spinules(Fig. 11H). Fig. 12 Neotisbella gigas n. sp. : A, male; B, first antenna; C, detail of first antenna segment seven,postero-lateral; D, maxilliped; E, base of endopod of first leg; F, fifth leg; G, sixth leg. ScalesO'l mm unless otherwise indicated. PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 227 Leg 5 $ (Fig. 11F) with single inner seta on baseoendopod about twice as long as free segment:free segment about 5-3 times longer than wide; its ventral surface covered with minute denticles;its lateral surface and the middle third of the medial surface bearing many spinules; armatureelements comprising 1 long plumose seta each at the distal ends of the lateral and medial margins,2 long plumose setae on the projecting distal margin and a short naked seta positioned betweenthem and the lateral seta. Leg 5 in <$ (Fig. 12F) as for female except inner seta on baseoendopodabout half as long as free segment. Leg 6 of <$ (Fig. 12G) comprising 1 short sparsely pinnate inner seta and 2 long sparsely pinnateouter setae situated laterally on genital lobes of urosome somite 2. Body length of $$ from 1-85 to 2-00 and $ 1-26 mm. MATERIAL EXAMINED. Holotype $, 1 $ and 5 $$ paratypes: N.E. Atlantic Ocean, 18 N 25 W'Discovery' Stn 7089. BM(NH) registration numbers 1977.226 (holotype), 1977.227 () and1977.228-232 ($$). REMARKS. The similarities between the male and females described above strongly suggest thatthey are conspecific. Apart from the obvious characters of urosome segmentation, structure ofthe first antenna and the leg 6, differences between the sexes were noted in the maxilliped, leg 1and leg 5. The presence of a spinous process on the third maxilliped segment has been recordedin males of Bathyidia remota and Volkmannia forficula. The minor differences between the sexesin the inner spine on the basis of the leg 1 and the inner seta on the baseoendopod of leg 5 canreadily be attributed to sexual dimorphism. Phylogenetic relationships of the new genera It is interesting to examine the possible phylogenetic relationships of the two new genera, Volk-mannia and Neotisbella, to other genera in the family Tisbidae. The new genera belong to thesubfamily Tisbinae which contains the following genera: Tisbe, Tisbella, Tisbintra, Bathyidia,Paraidya, Scutellidium Claus, 1866 and Sacodiscus Wilson, 1924. The aberrant genus CholidyaFarran, 1914 is profoundly modified for its parasitic mode of life and is here regarded as repre-senting a separate subfamily, the Cholidyinae subfam. nov. Scutellidium and Sacodiscus are closelyrelated and will be called the Scutellidium group of genera, all other genera will be referred to asthe Tisbe group. These two groups of genera are distinguished primarily by the structure of themouthparts. Within the Tisbe group the main characters used for separating the genera are the structure andarmature of the second antenna, mandible, leg 1 and caudal ramus. Consideration of thesecharacters within a phylogenetic framework suggested the following scheme of affinities (Fig. 13). The main events occurring during the evolutionary radiation of this group of genera are desig-nated, A, B and C (in Fig. 13). Event A resulted in the divergence of the ancestral stock into twolines, the VB lineage (Volkmannia-Bathyidid) and the TP lineage (Tisbe-Paraidyd). Event A wasthe adoption of a planktonic habit by the VB lineage and the retention of the ancestral benthichabit by the TP lineage. The change to a planktonic existence appears to be associated with theacquisition of an elongate caudal ramus armed with 9 armature elements, as possessed by all 3genera in the VB lineage. The benthic TP lineage typically possess a short caudal ramus bearingonly 6 or 7 armature elements. The second major event (B) seems to have occurred twice, once ineach main lineage. This was the divergence from an ancestral stock with a leg 1 endopod comprisingthree large segments of a stock with a reduced third endopod segment. The genera Bathyidia andParaidya both retained large third segments on their leg 1 endopods. The third major event (C)was the splitting off from an ancestral stock possessing a reduced third segment on the leg 1endopod of a stock in which the separate third segment is lost altogether. This appears to havetaken place at least twice, probably three times; once in the derivation of the Neotisbella line fromthe ancestral Volkmannia stock and probably twice in the independent separation of the Tisbellaand Tisbintra lines from the ancestral Tisbe stock. This scheme of phylogenetic relationships allows for the obvious close relationship of Volk-mannia, Neotisbella and Bathyidia (as indicated by their shared derived characters) despite their 228 G. A. BOXSHALL Tisbe Volkmannia Paraidya Bathyidia ancestral stock Fig. 13 The affinities of the seven genera of the Tisbe group within the subfamily Tisbinae. close phenetic similarities to Tisbe, Tisbella and Paraidya respectively. The progressive reductionof the third segment of the leg 1 endopod has resulted in the formation of a 2-segmented endopodindependently in Neotisbella, in Tisbella and in Tisbintra. In the first two genera the endopod isrelatively short and the distal endopod segment retains the combined armature elements of bothsecond (the single inner seta) and third segments (the 3 distal elements). This condition couldhave been derived from an endopod similar to that found in Bathyidia and Paraidya. In Tisbintrathe endopod is much longer than the exopod and the distal endopod segment possesses 1 innerseta and only 1 or 2 distal elements. This condition was probably derived from a more Tisbe-likestock. Family TACHIDIIDAE Genus EUTERPINA Norman, 1903DIAGNOSIS. As for type-species.TYPE-SPECIES. Euterpina acutifrons (Dana, 1848). PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 229 Euterpina acutifrons (Dana, 1848) Harpacticus acutifrons Dana, 1848 : 153. Euterpe gracilis Claus, 1863 : 110, pi. XIV, figs 1-13. DIAGNOSIS. Prosome 4-segmented, first thoracic somite fused to head; urosome 5-segmented in $(Fig. 14G) and 6-segmented in $. Genital complex ($) without subdividing suture line. Rostrumwell developed, anteriorly directed. Caudal rami just longer than wide. First antenna ($) 7-seg-mented (Fig. 14H) with 2 terminal aesthetes; (^) indistinctly 5-segmented, chirocerate and with 2aesthetes on claw-like distal segment (Fig. 14K). Second antenna (Fig. 141) with basis bearing1 -segmented exopod and 2-segmented endopod. Mandible with poorly developed biramous palp,without setae on basis. First maxilla arthrite well developed with about 12 mostly spiniform arma-ture elements, rami rudimentary. Second maxilla with well-developed basis and small 2-segmentedendopod. Maxilliped slender, 3-segmented; the long terminal claw armed with several strongsetules. Rami of leg 1 short and 2-segmented, displaying weak sexual dimorphism with the ramibeing longer and more slender in $ (Fig. 14L) than in $. Legs 2-4 usually with 3-segmented rami,endopod of leg 2 in ^ sometimes displaying incomplete separation of segments 2 and 3 giving2-segrnented appearance; armature formula as follows: Coxa Basis Endopod Exopod Leg 1 0-0 0-1 0-1 ; 1,1,4 1-0; III, 2, 2 Leg2 0-0 0-0 0-1; 0-2; I, 2, 2 1-1 ; 1-1 ; II, I, 3 Leg 3 0-0 0-0 0-1; 0-2; I, 2, 2 1-1; 1-1; II, I, 3 Leg 4 0-0 0-0 0-1 ; 0-1 ; I, 2, 2 1-1 ; 1-1 ; II, I, 2 Leg 5 ($) a flattened plate armed with 4 distal margin spines and 2 elements on the outer margin;a proximal seta, a short spine in the middle of the margin and a fine setule originating in the axilof this spine (Fig. 14J). Leg 5 (<) with both legs fused into a single plate with a median notch inthe distal margin, each leg bearing 2 distal margin spines and 3 elements on the outer margin, aproximal seta, a short spine in the middle of the margin and a fine setule originating in the axilof the spine (Fig. 14M). Leg 6 (Fig. 14N) in <$ a small prominence bearing 2 serrate spines apically. Body lengths of? 0-50-0-75 mm and $ 0-50-0-56 mm. MATERIAL EXAMINED. 1 $: Antarctic, Terra Nova' Expedition (Farran, 1929). BM(NH) registra-tion numbers 1930.1.1.1569-70. 4$$: Cheshire coast. BM(NH) registration numbers 1945.10.29.21-23. 10$$, 1 <$: Starcross, Devon. BM(NH) registration numbers 1911.11.8.43189-198. REMARKS. Both sexes of this species are easily recognizable and are rarely confused with otherspecies. The fine lateral setule present in the axil of the outer margin spine on leg 5 has beenreported previously in both the male (e.g. Klie, 1913; Haq, 1965) and the female (e.g. Giesbrecht,1892; Mori, 1964; Haq, 1965). This setule is not illustrated in either sex by Sars (1921) or in themale by Chappuis (1936) and Giesbrecht (1892). It is probable that the setule has been overlookedby the latter group of authors. It was even found to be present in both morphs of male E. acuti-frons studied by Haq (1965). Family THALESTRIDAEGenus PARATHALESTRIS Brady and Robertson, 1873 DIAGNOSIS. Prosome 4-segmented, urosome 5-segmented in $ and 6-segmented in <$. Body cylin-drical or slightly laterally compressed; epimeral plates of free thoracic somites not markedlyproduced. Rostrum short, antero-ventrally directed. First antenna ($) 7- to 9-segmented, without plumose setae. Second antenna with allobasis and2-segmented exopod. Mandible palp well developed; basis with 3 setae, both rami 1 -segmented.First maxilla with 1 -segmented exopod and endopod. Second maxilla with 3 endites on coxa,endopod rudimentary. Maxilliped with 2 robust basal segments and strong terminal claw. 230 G. A. BOXSHALL Fig. 14 Parathalestris croni : A, female ; B, second antenna ; C, first leg ; D, fifth leg ; E, male urosome ;F, fifth leg. Euterpina acutifrons: G, female; H, first antenna; I, second antenna; J, fifth leg;K, male first antenna; L, first leg; M, fifth leg; N, sixth leg. Scales 0-1 mm unless otherwiseindicated. PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 231 Leg 1 with both rami 3-segmented, about equal in length; exopod segment 2 and endopodsegment 1 providing most of length of respective rami. Legs 2-4 with 3 segmented rami in $;leg 2 displaying sex dimorphism, with endopod usually 2-segmented in <$. Armature formula asfollows: Coxa Basis Endopod Exopod Leg 1 0-0 1-1 0-1; 0-0; 3 or 2 I-0;I-l;4or5 Leg 2 0-0 1-0 0-1; 0-2; I, 2, 2 1-1 ; 1-1 ; II, I, 4 Leg 3 0-0 1-0 0-1 ; 0-1 ; I, 2, 3 1-1 ; 1-1 ; II, I, 5 Leg 4 0-0 1-0 0-1 ; 0-1 ; I, 2, 2 1-1 ; 1-1 ; II, I, 5 Leg 5 $ baseoendopod strongly projecting and usually bearing 5 setae, exopod usually with 6or 7 setae. Leg 5 ^ usually with 3 setae on baseoendopod and 6 or 7 on exopod.Leg 6 in <$ represented by 3 setae on genital lobes of urosome somite 2. TYPE-SPECIES. Parathalestris clausi (Norman, 1868). REMARKS. Sars (1905) erected a new genus, Halithalestris, to include the species Harpacticus croni,first recorded by Kroyer (1842). One of the major characters used by Sars to establish the newgenus was the pelagic habits of H. croni. Lang (1948) recognized that Halithalestris was not adistinct genus and subsequently referred H. croni to Parathalestris. Parathalestris croni (Kroyer, 1842) Harpacticus croni Kroyer, 1842 : pi. XLIII, figs 3a-n.Thalestris serrulata Brady, 1880 : 133, pi. LIX, figs 2-11.Halithalestris croni Sars, 1905 : 118, pi. LXXII. DIAGNOSIS. Cephalosome small, comprising about 50% of length of prosome (Fig. 14A); genitalcomplex in $ only subdivided laterally by a suture line. Anal somite markedly notched in middleof posterior border (Fig. 14E). Caudal rami divergent, about 3-5-4 times longer than maximumwidth. First antenna of $ 9-segmented, bearing a large aesthete on segment 4; $ indistinctly 7-seg-mented with aesthetes on segments 3 and 4. Second antenna (Fig. 14B) with 1 seta on allobasis;exopod segments 1 and 2 with 1 and 4 setae respectively. First segment of maxilliped with 3distal setae, terminal claw shorter than second segment. Both rami of leg 1 (Fig. 14C) similar in length; inner claw on distal segment of endopod about2 times longer than outer claw; exopod segment 3 with 4 armature elements. Leg 5 ($) extendingposteriorly as far as middle of genital complex ; baseoendopod armed with 5 setae and extendingjust beyond mid-point of exopod; exopod oval in outline, about twice as long as wide and armedwith 6 setae (Fig. 14D). Leg 5 (<$) smaller than in $, baseoendopod with 3 setae and exopod with6 setae (Fig. 14F). Leg 6 in ^ represented by 3 setae on lateral lobe of urosome 2 (Fig. 14E). Body length of $ from 2-1 to 2-3 mm and $ about 1*7 mm. MATERIAL EXAMINED. 1 ?, 1 <J; Firth of Forth. BM(NH) registration numbers 1911.11.8.46207-10. REMARKS. This is one of the largest species of harpacticoid and is easily distinguished by its size,small cephalosome and long divergent caudal rami. Brady (1880) first described the male, asThalestris serrulata, and figured the male leg 5. Wells (1970) misinterpreted Brady's figure when heredrew the leg 5, as he illustrated only 5 setae on the exopod (Wells, 1970 : fig. 7e $) instead ofthe 6 in Brady's figure. Family CLYTEMNESTRIDAE Genus CLYTEMNESTRA Dana, 1848 DIAGNOSIS. Prosome 4-segmented, first thoracic somite fused to head, urosome 5-segmented in?, 6-segmented in $\ body rather dorso-ventrally flattened, cephalosome and free thoracic somites 232 G. A. BOXSHALL with large, conspicuous epimeral plates. Urosome slender; genital complex without subdividingsuture line. Rostrum large, anteriorly directed. Caudal ramus at least as long as wide, with 6armature elements, 2 of which are long in <$. First antenna 7- or 8-segmented, with several aesthetes. Second antenna comprising a basis, a2-segmented endopod and either 1 or 2 plumose setae representing the exopod (Fig. 15F). Man-dible reduced to slender blade and palp represented by single minute setule. First maxilla 2-segmented, proximal segment with 1 lateral seta, distal segment with 2 apical elements. Secondmaxilla reduced, 2-segmented, bearing 1 proximal seta and a distal endite armed with 2 setae onfirst segment and 3 setae on second segment. Maxilliped long, consisting of 2 segments and aterminal claw; showing weak sexual dimorphism with longer terminal claw in <$ (Fig. 15G) thanin? (Fig. 15D). Leg 1 with 3-segmented endopod and 1 -segmented exopod. Legs 2-4 each with transverselyelongate basis and 3-segmented rami : armature formula variable on legs 1 and 2 between speciesbut within following limits : Coxa Basis Endopod Exopod Legl 0-0 0/1-0 0-1; 0-1; 0,2,2 3/4 Leg 20-01-0 0-1 ; 0-2; I, 2, 2 0/1-1 ; 1-1 ; II, 2, 2/3 Leg 3 0-0 1-0 0-1 ; 0-2; I, 2, 3 1-1 ; 1-1 ; III, 2, 3 Leg 4 0-0 1-0 0-1; 0-2; I, 2, 2 1-1; 1-1; HI, 2, 3 Leg 5 without inner setae on baseoendopod ; free segment elongate with 5 or 6 slender setae.Leg 6 in $ represented by an elongate lobe bearing 1 lateral and 2 apical setae. TYPE-SPECIES. Clytemnestra scutellata Dana, 1848. REMARKS. Lang (1948) in his monograph on the Harpacticoida retained Poppe's (1891) family-group name, Pseudopeltiidae, for the genus Clytemnestra which was its type and only genus. Thisaction has been followed by several subsequent authors (e.g. Wells, 1970) but it contravenes theICZN Article 1 le as a family-group name must, when first published, be based on the name thenvalid for a contained genus. Thus the family-group name Clytemnestridae, first proposed by Scott(1909), is adopted here. Clytemnestra scutellata Dana, 1848 Goniopelte gracilis Claus, 1891 : 151, pi. I-II.Clytemnestra hendorffi Poppe, 1891 : 132, pi. I. DIAGNOSIS. Caudal rami (Figs 15B, J) about 1-8 times longer than greatest width. First antenna8-segmented; $ with 1 aesthete on segment 4 and 2 each on segments 5 and 8; relative lengths ofsegments 3 : 10 : 10 : 10 : 12 : 10 : 15 : 30 (Fig. 15C); $ with 2 aesthetes each on segments 4, 5 and8; relative lengths of segments 3 : 7 : 14 : 3 : 28 : 5 : 16 : 24 (Fig. 15E). Exopod of second antenna(Fig. 15F) represented by 2 plumose setae. Basis of leg 1 (Fig. 15H) with outer margin seta;exopod with 4 distal setae. Leg 2 (Fig. 151) exopod segment 1 without outer margin spine;endopod segment 1 of legs 2-4 as long as exopod segments 1 and 2 combined. Free segment ofleg 5 typically with 6 setae in both sexes (Fig. 15K), occasionally with 5 (var. quinquespinosd).Body length of? from 1 to 1-24 mm, and of <$ from 1*07 to 1*3 mm. MATERIAL EXAMINED. 1 ?, 1 #: N.E. Atlantic Ocean, 18 N 25 W, 'Discovery' Stn 7089. BM(NH)registration numbers 1977.194 (?) and 1977.195 (<J). 1 ?, \ <$: Suez Canal Expedition (Gurney,1927). BM(NH) registration number 1928.4.2.136. 10 $$, 2 &?: as C. rostrata, Gulf of Guinea(Scott, 1894). BM(NH) registration numbers 1893.4.22.268-275. REMARKS. This species can be distinguished from C. rostrata, the only other species in the genus,by the shape of the caudal rami and the segmentation of the first antenna when sorting un-dissected specimens. There are other significant differences between the two species, particularlyin the armature of legs 1 and 2. PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 233 Fig. 15 Clytemnestra scutellata: A, female; B, caudal ramus; C, segments four to seven of firstantenna; D, maxilliped; E, male first antenna; F, second antenna; G, maxilliped; H, first leg;I, second leg; J, caudal ramus; K, fifth leg. C. rostrata: L, female; M, caudal ramus; N, firstantenna; O, first leg; P, fifth leg; Q, male first antenna. (Q redrawn from Giesbrecht, 1892.)Scales 0-1 mm unless otherwise indicated. 234 G. A. BOXSHALL Clytemnestra rostrata (Brady, 1883)Goniopsyllus rostratus Brady, 1883 : 107, pi. XLII, figs 9-16. DIAGNOSIS. Caudal rami (Fig. 15M) about 1-1-1 times longer than wide. First antenna 7-seg-mented ; $ with 1 aesthete on segment 4 and 2 each on segments 5 and 7, relative lengths of seg-ments about 3 : 12 : 6 : 10 : 12 : 11 : 46 (Fig. 15N): $ with 2 aesthetes on segments 4, 5 and 7,relative lengths of segments about 4 : 7 : 16 : 8 : 14 : 23 : 28 (Fig. 15Q). Exopod of second antennarepresented by 1 plumose seta. Basis of leg 1 (Fig. ISO) without outer margin seta; exopod with3 distal setae. Leg 2 exopod segment 1 with an outer margin spine, exopod segment 3 with only 6armature elements compared with 7 in C. scutellata : endopod segment 1 of legs 2-4 almost aslong as exopod segments 1 and 2 combined. Free segment of leg 5 typically carrying 5 setae inboth sexes (Fig. 15P), occasionally reduced to 4 setae.Body length of $ from 0-60 to 1-00 mm, and < from 0-80 to 0-90 mm. MATERIAL EXAMINED. Holotype? as Goniopsyllus rostratus: Challenger Expedition (Brady, 1883).BM(NH) registration number CC. 46. 1 $: Great Barrier Reef Expedition (Farran, 1936).BM(NH) registration number 1948.4.28.120. 7 $$: Gulf of Guinea (Scott, 1894). BM(NH)registration numbers 1893.4.22.268-275. REMARKS. The holotype of C. rostrata was described by Brady (1883) as a male, but re-examinationof this specimen has shown it to be a female. It possesses a 7-segmented first antenna, with 1aesthete on segment 4, and 2 aesthetes on segments 5 and 7. The relative lengths of segments 5, 6and 7 are 12 : 9 : 36 respectively (as percentages of the total appendage length). The armature andproportional lengths of the segments indicate that this appendage belongs to a female. Family MIRACHDAE DIAGNOSIS. Prosome 4-segmented with first thoracic somite fused to head, urosome 5-segmented in$ and 6-segmented in <. Body slender, slightly laterally compressed. Rostrum variable. Caudalrami longer than wide. First antenna 7- to 8-segmented in $, 8- to 9-segmented and haplocerate inc. Exopod of second antenna 1 -segmented or absent. Mandible with small toothed blades andrudimentary palp. First maxilla with several cutting elements on arthrite, rest of appendagerudimentary. Second maxilla with small number of endites. Maxilliped well developed, 2-seg-mented with third segment apparently fused to short terminal claw. Leg 1 with 3-segmented exopodand 2-segmented endopod; legs 2-4 with 3-segmented rami except for leg 2 displaying sexualdimorphism with 2-segmented endopod in . Leg 5 ($) comprising a short baseoendopod bearing3-5 setae and elongate exopod armed with 6 setae. Leg 5 (<$) with short baseoendopod bearing 2or 3 setae, exopod bearing 4 or 6 setae. Genus MIRACIA Dana, 1846 DIAGNOSIS. Cephalosome quite large, rounded anteriorly and provided with a pair of large cuti-cular lenses (Fig. 16A). Rostrum inconspicuous. Urosome somites 3-5 (6 in^) each provided witha row of spinules ventrally along posterior border. Caudal rami about 3 times longer than wide.Fitst antenna 8-segmented in $ carrying an aesthete on segment 4; in 9-segmented, with aestheteon segment 5 and geniculate between segments 6 and 7. Second antenna (Fig. 16B) with 1 -seg-mented exopod bearing 2 apical plumose setae. Armature formula of legs 1-4 variable. Leg 5 as in family diagnosis for both sexes. Leg 6 represented in by a small lateral lobe bearing3 setae. TYPE-SPECIES. Miracia efferata Dana, 1852. REMARKS. The armature formula given by Lang (1948) for the genus Miracia applies only to M.minor, not M. efferata. PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 235 Miracia efferata Dana, 1852 DIAGNOSIS. Cuticular lenses on cephalosome touching. Second antenna (Fig. 16B) with allobasis,as basis and first endopod segment completely fused. Armature formula of legs 1-4 as follows : Coxa Basis Endopod Exopod Legl 0-0 1-1 0-1; 3 1-0; 1-1; 4 Leg 2 0-0 1-0 0-1; 0-2; I, 1,2 1-0; 1-1; II, 2, 2 Leg3 0-0 1-0 0-1; 0-2; I, 2, 2 1-0; 1-1; III, 2, 3 Leg 4 0-0 1-0 0-1; 0-1; 1,2, 2 1-0; 1-1; III, 2, 3 Legs 5 (?) with 5 setae on baseoendopod and 6 setae on exopod (Fig. 16C). Leg 5 (<) with 3setae on baseoendopod and 6 setae on exopod (Fig. 16D).Body length of $ from 1-45 to 2 mm and $ from 14 to 1*6 mm. MATERIAL EXAMINED. 31 ??, 8 &?: N.E. Atlantic Ocean, 18N 25 W, 'Discovery' Stn 7089.BM(NH) registration numbers 1977.196-205 (?$) and 1977.206-213 (&?). REMARKS. Both sexes of M. efferata were a bright bluish-purple colour even after a considerabletime in preservative. The armature formula of legs 2-4 differs in several respects from that pre-sented by Lang (1948) for the genus Miracia. The most significant differences are the presence ofinner margin setae on endopod segment 1 of legs 2-4 and the presence of 3 outer margin spineson exopod segment 3 of legs 3 and 4. Lang's formula was presumably based only on data fromM. minor Scott, 1894. Miracia minor Scott, 1894 DIAGNOSIS. Body (Fig. 16E) more slender than in M. efferata (c.f. Fig. 16 A). Cuticular lenses oncephalosome not touching. Second antenna apparently with basis and 2-segmented endopod.Armature formula of legs 1-4 as follows : Coxa Basis Endopod Exopod Legl 0-0 1-1 0-1; 3 1-0; 1-1; 4 Leg 20-01-0 0-0; 0-2; I, 1, 2 1-0; 1-1; II, 2, 2 Leg 3 0-0 1-0 0-0; 0-2; I, 2,2 1-0; 1-1; II, 2, 3 Leg 4 0-0 1-0 0-0; 0-1; 1,2,2 1-0; 1-1; II, 2, 3 Leg 5 (?) with 4 setae on baseoerdopod, 1 very long and plumose, and with 6 setae on exopod(Fig. 16G). Leg 5 ($) with 2 setae on baseoendopod and 4 setae on exopod, 2 distally and 2 on thelateral margin (Fig. 16F). Body length of? from 0-90 to 0-93 mm and ^ 0-82 to 0-93 mm. MATERIAL EXAMINED. Syntype series $$ and^: Gulf of Guinea (Scott, 1894). BM(NH) registra-tion numbers 1893.4.22.340 and 1894.1.20.76-87. 1 ?, 1 <$: as Macrosetella oculata, John MurrayExpedition (Sewell, 1947), BM(NH) registration numbers 1949.12.31.584-5. 1 ?: Gulf of Aden.BM(NH) registration number 1911.11.8.43199. REMARKS. There is some confusion in the literature over the armature of the leg 5 in both sexes ofM. minor. This arose because Scott (1894) in his original description illustrated 7 setae on the ?leg 5 exopod, and no outer margin seta on the baseoendopod. Examination shows that thearmature of the $ leg 5 comprises 1 outer margin seta on the baseoendopod and 6 setae on theexopod in agreement with Giesbrecht (1895). Scott (1894) also figured the exopod of the $ leg 5with 2 inner margin setae and 2 distal setae. The complete male specimen in the syntype seriesshows that in the slide (No. Z.D. 76) prepared by Scott the exopod had been accidentally rotatedso the 2 outer margin setae (shown in Fig. 14F) appeared to be on the inner margin. Giesbrecht(1895) figured the $ leg 5 with 2 outer margin setae and 2 distal setae but most other authors(e.g. Owre and Foyo, 1967; Wells, 1970) redrew their illustrations from Scott (1894). 236 G. A. BOXSHALL Fig. 16 Miracia efferata: A, female; B, second antenna; C, fifth leg; D, male fifth leg. M. minor:E, syntype male; F, fifth leg; G, female fifth leg. Macrosetella gracilis: H. female; I, fifth leg; J,male fifth leg; K, rostrum. Oculosetella gracilis: L, female cephalosome; M, fifth leg; N, male fifthleg. (L redrawn from Sars, 1916; M & N redrawn from Owre & Foyo, 1967.) Scales 0-1 mm unlessotherwise indicated. PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 237 Genus OCULOSETELLA Dahl, 1895DIAGNOSIS. As for type-species.TYPE-SPECIES. Oculosetella gracilis (Dana, 1852). Oculosetella gracilis (Dana, 1852) Miracia gracilis Dana, 1852 : 46. Setella oculata Sars, 1916 : 7, 13, Fig. VII. Macrosetella oculata Rose, 1929 : 54. DIAGNOSIS. Cephalosome rounded anteriorly, provided with large cuticular lenses touching in themedian line. Rostrum large, clearly delimited at base and ventrally directed (Fig. 16L). Urosomesomites 3-5 (6 in <) each provided with a spinule row ventrally along posterior border. Caudalrami about 3 times longer than wide. First antenna 7-segmented in $; 8-segmented and geniculatein c. Second antenna (Fig. 16L) with allobasis; exopod absent. Leg 5 ($) with 3 setae on baseoendopod and 6 setae on exopod (Fig. 16M). Leg 5 ($) with 2setae on baseoendopod and 4 setae on exopod (Fig. 16N). Body length of $ from 1-2 to 1-35 mm and $ from 1-15 to 1-3 mm. MATERIAL EXAMINED. None. REMARKS. This species is rather incompletely known as some of its appendages have not beendescribed. The two specimens of Macrosetella oculata reported by Sewell (1947) were found onre-examination to be Miracia minor. Genus MACROSETELLA Scott, 1909DIAGNOSIS. As for type-species.TYPE-SPECIES. Macrosetella gracilis (Dana, 1848). Macrosetella gracilis (Dana, 1848)Setella gracilis Dana, 1848 : 155. DIAGNOSIS. Cephalosome prolonged anteriorly (Fig. 16H), without cuticular lenses. Rostrumlarge, clearly delimited at base and ventrally directed (Fig. 16K). Caudal rami about 8 timeslonger than wide. First antenna 8-segmented in both sexes with aesthetes on segments 4 and 8.Second antenna with allobasis in $ and apparently with separate basis and 2-segmented endopodin $; exopod absent in both sexes. Mandible and first maxilla both comprising a toothed bladeand a single seta representing the palp. Second maxilla with 1 ($) and 2 ($) endites. Maxillipedslender. Armature formula of legs 1-4 as follows : Coxa Basis Endopod Exopod Leg 1 0-0 1-0 0-1; 3 1-0; 1-0; 3 Leg 2 0-0 0-0 0-0; 0-2; 1,2, 1 1-0; 1-1; 11,2,2 Leg 3 0-0 0-0 0-1 ; 0-1 ; I, 2, 2 1-0; 1-1; II, 2, 3 Leg 4 0-0 0-0 0-1; 0-1; I, 2, 2 1-0; 1-1; II, 2, 3 Leg 5 ($) with 4 setae on baseoendopod and 6 setae on exopod (Fig. 161). Leg 5 (<) with 2setae on baseoendopod and 4 setae on exopod (Fig. 16J).Body length of $ from 1-21 to 1-5 mm and <$ from 1-13 to 1-16 mm. MATERIAL EXAMINED. 21 ??, 1 g: N.E. Atlantic Ocean, 18 N 25 W 'Discovery' Stn 7089.BM(NH) registration numbers 1977.214-223 (?$) and 1977.224 (). 238 G. A. BOXSHALL REMARKS. This is the only member of the family Miraciidae without conspicuous cuticular lenses.It possesses only a simple eye spot. SIPHONOSTOMATOIDA This order as defined bj Kabata (1979) comprises both the Caligoida, containing primarilyparasites of fishes, and the Cyclopoida Siphonostoma, which are predominantly associated withor parasitic upon invertebrate hosts. Although adult and, more commonly, juvenile fish parasiticsiphonostomatoids are occasionally recorded free in the plankton they are not true holoplanktonicforms and are not considered further. Siphonostomatoid copepods belonging to three genera,Ratania Giesbrecht, Pontoeciella Giesbrecht and Hyalopontius Sars (= Megapontius Hulsemann),have been found in the plankton of the N.E. Atlantic Ocean and can be regarded as members ofthe planktonic community. Species of these three genera are probably associated with planktonicinvertebrates but no 'hosts' are known at present. Family RATANIIDAEGenus RATANIA Giesbrecht, 1891 DIAGNOSIS. Body unmodified; urosome 5-segmented in female, 6-segmented in male. Caudalramus with 6-setae. Rostrum weakly developed. First antenna 5- to 7-segmented ($) and 7- to9-segmented (^), with an aesthete on the terminal segment. Second antenna non-prehensile,4-segmented and without trace of exopod. Oral cone short. Mandible an elongated blade, dentateapically and without palp. First maxilla bilobed; inner lobe with 3 equal setae, outer lobe with 3setae and a short naked seta. Second maxilla 2-segmented, distal portion of second segmentproduced into a slightly curved claw. Maxilliped 3-segmented and with terminal claw armed witha spinulate seta.Legs 1-4 with 3-segmented rami; armature formula for both sexes as follows: Leg 5 with a free segment armed with 2 short medial and 3 long lateral setae.Leg 6 represented by 2 small spines in the female and by a large postero-ventral flap bearing asingle seta in the male. TYPE-SPECIES. Ratania flava Giesbrecht, 1891. REMARKS. Ratania shows a close affinity to the family Myzopontiidae, but differs from the generaof this family, primarily in the absence of an exopod on the second antenna, in the reducednumber of segments in the first antenna, in the small oral cone and in the structure of the bladeof the mandible (Heron & Damkaer, 1969). Ratania flava Giesbrecht, 1891 DIAGNOSIS. Female. Prosome about 2-2 times longer than urosome. Ratio of lengths of urosomesomites and caudal ramus (Fig. 17E) 14: 30: 12: 11 : 16 : 17. Caudal ramus about 1-7 timeslonger than wide. First antenna 5-segmented; relative lengths of segments (measured along posterior border)23 : 7 : 5 : 35 : 30 (Fig. 17F); segmental armature elements 1-6, II-2, III-2 + 1 aesthete, IV-5,V-5 + 2 aesthetes. Second antenna (Fig. 17G) with terminal seta about 3 times longer than distalsegment. Tip of mandible (Fig. 17H) with two dentate areas well separated. Inner lobe of firstmaxilla (Fig. 171) markedly longer than outer lobe. Free segment of leg 5 (Fig. 17E) somewhatexpanded laterally, setae on leg 5 not conspicuously plumose. PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 239 Fig. 17 Ratania atlantica: A, female; B, first antenna; C, male urosome; D, first antenna. R.flava:E, female urosome; F, first antenna; G, second antenna; H, mandible; I, first maxilla; J, male;K, first antenna. (A-D redrawn from Heron & Damkaer, 1969.) Scales 0-1 mm unless otherwiseindicated. 240 G. A. BOXSHALL Body length of female 1-1-1-2 mm. Male. As for? except: prosome about 1-9 times longer than urosome (Fig. 17J). Ratio of lengthsof urosome somites and caudal ramus 14: 16 : 14: 13 : 11 : 14: 18. First antenna (Fig. 17K)7-segmented; relative lengths of segments 23:11:15:6:13:14:18. Segmental armatureelements 1-6, II-5, III-3, IV-1, V-2, VI-1, VII-6+2 aesthetes. Body length of male 1-1-2 mm. MATERIAL EXAMINED. 7?$ and 1 <$; 'Discovery' Stn 7089. BM(NH) registration numbers 1977.242-248 ($?) and 1977.249 (). REMARKS. Saraswathy (1961) reported that many of the segments of the 5-segmented first antennain $ R. flava showed subdivisions. No significant subdivisions were observed in the presentmaterial, and the segmentation of the first antenna remains a useful character in distinguishingbetween the two species of Ratania. Ratania atlantica Farran, 1926 DIAGNOSIS. Female. Prosome from 1-9 to 2-3 times longer than urosome (Fig. 17 A); relativelengths of urosome somites and caudal ramus 14 : 29 : 15 : 10 : 13 : 19. Caudal ramus from 2-3to 2-5 times longer than wide. First antenna (Fig. 17B) 7-segmented, relative lengths of segments 25 : 8 : 4 : 8 : 9 : 13 : 33;segmental armature elements 1-7, II-3 + 1 aesthete, III-2, IV-3, V-2, VI-2, VII-11 +2 aesthetes.Tip of mandible with two dentate areas separated by small indentation. Inner lobe of first maxillajust longer than outer lobe. Free segment of leg 5 not markedly expanded laterally. Body length 2-21-2-8 mm. Male. Prosome about 1-9 times longer than urosome. Relative lengths of urosome somitesand caudal ramus (Fig. 17C) 10 : 21 : 15 : 13 : 9 : 13 : 19. Caudal ramus about 2-2 times longerthan wide. First antenna (Fig. 17D) 9-segmented, relative lengths of segments 16:11:3:8:5:4:16:8:19; segmental armature elements 1-4 + 3 aesthetes, II-4, III-2, IV-3; V-l, VI-1, VII-2, VIII-2 + 1aesthete, IX-8 + 1 aesthete. Body length 2-42-2-62 mm. MATERIAL EXAMINED. Holotype $: Bay of Biscay (Farran, 1926). BM(NH) registration numbers1926.12.6.40 (spirit) and 1926.12.6.52 (slide of appendages). 2 ?$: Antarctic (between 66 30'and 76 S), Terra Nova Stns 276 and 285 (Farran, 1929). BM(NH) registration numbers1930.1.1.1330-1333 (spirit) and 1930.7.24.91 (slide of appendages). REMARKS. The holotype of R. atlantica is in poor condition. The slide of the appendages containsone of the first antennae, it is 7-segmented and the relative lengths of the segments are as follows24: 11:4: 11: 10: 11: 29. The armature elements remaining on the appendage are in agreementwith the formula given by Heron & Damkaer (1969). The body length of the holotype, 2-34 mm,also serves to distinguish between R. atlantica and the smaller R. flava. The two Antarctic speci-mens are poorly preserved, but their large size and the 7-segmented nature of the first antennae ofone of them confirm that these specimens are R. atlantica. Family PONTOECIELLIDAE Genus PONTOECIELLA Giesbrecht, 1895 DIAGNOSIS. Female. Body unmodified (Fig. ISA), urosome 5-segmented. Caudal ramus with 6setae, ventral seta strongly spinulate. Rostrum weakly developed. First antenna (Fig. 18C) 8-segmented with an aesthete on segment VI. Second antenna (Fig. 18D) non-prehensile, with a1-segmented exopod bearing 1 or 2 apical setae. Oral cone long, forming a true siphon (Fig. 18B).Mandible (Fig. 18E) a slender, elongate blade without a palp. First maxilla (Fig. 18F) a single Fig. 18 Pontoeciella abyssicola: A, holotype female; B, female cephalosome lateral; C, first antenna;D, second antenna; E, mandible; F, first maxilla; G, second maxilla; H, maxilliped; I, male; J,anterior portion of urosome, lateral; K, first antenna; L, first antenna from another specimen;M, second antenna; N, oral cone, lateral; O, second maxilla; P, maxilliped; Q, first leg; R, fifthand sixth lees. Scales fH mm unless otherwise indicated. 242 G. A. BOXSHALL lobe with 2 apical setae and (sometimes) a small spinule. Second maxilla (Fig. 18G) 2-segmented,distal segment curving through between 65 and 90. Maxilliped (Fig. 18H) 4-segmented.Legs 1-4 with 3-segmented rami; armature formula variable but usually as follows: Coxa Basis Endopod Exopod Leg 1 0-1 1-0 0-1; 0-2; 1, 2, 3 1-0; 0-1; MI, I, 3 Leg 2 0-1 1-0 0-1; 0-2; 1,2, 3 1-1 ; 1-1 ; II, I, 3 Leg 3 0-1 1-0 0-1; 0-2; 1, I, 3 0-1; 1-1; II, I, 3 Leg4 0-1 1-0 0-1; 0-2; 1,1,2 0-1 ; 1-1 ; I, I, 3 Leg 5 reduced to a single seta. Male. Body unmodified (Fig. 181); urosome 6-segmented, first somite with ventral swelling(Fig. 18J), second somite narrower ventrally, producing slightly flexed appearance in lateral view.Ventral seta on caudal ramus thin-walled, not spinulate. First antenna (Figs 18K, L) 6-segmented, the distal segment providing between 75 and 90% ofthe overall length of the appendage; one aesthete present on segment III and one on segment V,the latter adhering along the entire length of the distal segment and projecting beyond its tip.Second antenna (Fig. 18M) with 1 -segmented exopod and 2-segmented endopod bearing a singleapical element. Mouth cone (Fig. 18N) short without true siphon. Second maxilla (Fig. 18O),distal segment armed with a single naked seta. Maxilliped (Fig. 18P) 4-segmented, terminal clawlong but weakly developed. Legs 1-4 (Fig. 18Q) as in female. Leg 5 (Fig. 18R) a small lobe fusedto somite and bearing 4 plumose setae. Leg 6 represented by a single seta. TYPE-SPECIES. Pontoeciella abyssicola (Scott, 1894). REMARKS. The new species described by Ummerkutty (1968), Danodes panikkari, obviouslybelongs to Pontoeciella. Pontoeciella abyssicola (Scott, 1894) lArtotrogus abyssicolus T. Scott, 1894: 128-129, pi. 12, figs 5-9, pi. 14, figs 11-18.Pontoeciella abyssicola Giesbrecht, 1895 : 186.Carnegiella gracilis Wilson, 1942 : 176, figs 20-25.Danodes plumata Wilson, 1942: 182-183, figs 57-68.Danodes panikkari Ummerkutty, 1968 ; 298-304, figs 1-13. DIAGNOSIS. As for genus (p. 240). MATERIAL EXAMINED. Holotype ? (as Artotrogus abyssicolus): Gulf of Guinea 1 55' N 5 55' E(T. Scott, 1894). BM(NH) registration number 1893.4.22.69a. 4 $?, 1 ^: Great Barrier ReefExpedition, Stns 20, 28, 45 and 48 (Farran, 1936). BM(NH) registration numbers 1948.4.28.132-135. 92?$, 4 <?: 'Discovery' Stn 7089, 18 N 25 W. BM(NH) registration numbers 1977.250-259($$) and 1977.260-263 (^). REMARKS. This species is highly variable both in the shape and proportions of the body and inthe structure and armature of some of the appendages. Female body length varies from 0-7 mm(Farran, 1936) to 1-65 mm (Heron & Damkaer, 1969) and body width relative to length rangesfrom 33 to 41 % (Farran, 1936). Variation in appendage structure and armature has been recordedfrom the first antenna to leg 5. According to Ummerkutty (1968), in Danodes panikkari the seta representing the female leg 5is absent. This difference alone is not sufficient to warrant the establishment of a distinct species,because of the variability exhibited by P. abyssicola, especially as this seta is often difficult toobserve (T. Scott in his original description did not observe this seta although it is still presenton his holotype specimen). Danodes panikkari is therefore regarded as a junior synonym ofPontoeciella abyssicola. The structure illustrated by Ummerkutty (1968, Fig. 7) as the first maxillais not the first maxilla of a Pontoeciella, which is unilobed, and requires re-examination. Less variation has been recorded in the males of P. abyssicola. However, a comparison of Far-ran's (1936, text-fig. 24d) and Wilson's (1942, fig. 20) figures with Fig. 161 shows variation in PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 243 body form, especially in relative lengths of the urosome somites. The relative lengths of segmentsof the first antenna also vary markedly, with the distal segment providing between 75 and 90 %of total appendage length. The male leg 5 is absent according to Scott (1894) and Wilson (1942),is represented by a single seta according to Farran (1936) or comprises four plumose setae(p. 242). Scott's male specimen is no longer extant but Farran's specimen from G.B.R. expeditionStn 20 was re-examined and the leg 5 was found to consist of 4 setae as in the 'Discovery' specimenillustrated in Fig. 18R. Only the most lateral seta is visible when the urosome is viewed from thedorsal aspect. Family MEGAPONTHDAE Genus HYALOPONTIUS Sars, 1909Syn. Megapontius Hulsemann, 1965. DIAGNOSIS. Both sexes. Body unmodified. Urosome 5-segmented in female, 6-segmented in male.Caudal ramus with 2 lateral, 2 dorsal and 3 apical setae, the latter situated in a concave depressionin the distal margin. Rostrum well developed, ventrally directed and sometimes truncate distally.First antenna 1 1 -segmented; relative lengths of segments similar in all spp. 19:1:2:2:2:5:4:9:10: 12: 34; segmental armature usually as follows: 1-6, H-l, III-2, IV-1; V-l, VI-6 + 1 spine,VII-1 + 1 spine, VIII-2, IX-2, X-2, XI-13 + 1 aesthete. Spine on segment VI usually pointed(Fig. 24E), that on segment VII often blunt (Figs 23D & 24E); aesthete on segment XI locatednear anterior margin about two thirds of distance along segment. Aesthete narrow and seta-likeproximally, becoming thin- walled and flaccid distally. Second antenna 2- to 3-segmented; distalsegment armed with a lateral spine, a small hirsute subapical seta and a very long terminal clawbearing a row of tiny spinules on its concave margin; exopod 1 -segmented bearing lateral andmedial naked setae and a sparsely pinnate apical seta. Oral cone short and well developed, with elaborate buccal tube distally; buccal stylets present.Mandible an elongate blade, dentate at tip and without palp. First maxilla bilobed; larger innerlobe with 3 apical setae, outer lobe with small spine and a long spinulate seta apically. Secondmaxilla 2-segmented, distal segment curved and dentate towards apex. Maxilliped 3-segmented;first segment usually bearing a unilaterally pinnate seta; second segment with a naked seta and arow of hairs along inner margin; terminal segment bearing 2 subapical setae and a long apicalclaw armed with a row of tiny hairs. Legs 1-4 with 3-segmented rami; armature formula within following range: Coxa Basis Endopod Exopod Leg 1 0-1 1-0 0-1; 0-2; 1, 2, 3 (O-I)-l; (0-I)-1; (II-III), 2, 3 Leg 2 0-1 1-0 0-1; 0-2; 1,2, 3 1-1 ; 1-1 ; (II-III), I, 5 Leg 3 0-1 1-0 0-1; 0-2; 1,2, 3 1-1 ; 1-1 ; (II-III), I, 5 Leg 4 0-1 1-0 0-1; 0-2; 1,2, 2 1-1 ; 1-1 ; II, I, 5 Leg 5 comprising basal segment armed with an outer seta and free segment bearing 1 apicaland 2 lateral setae. Leg 6 represented by a single seta in female and by a genital lobe bearing 1long seta and 2 spinules in male. TYPE-SPECIES. Hyalopontius typicus Sars, 1909. REMARKS. Sars (1909) described H. typicus in detail and comparison of his description with thatof Megapontius gigas (Hulsemann, 1965) clearly demonstrates that the two genera, Hyalopontiusand Megapontius, are synonymous. Sars (1909) placed Hyalopontius in the monotypic Pontoeciel-lidae but there are significant differences between these two genera. Hulsemann (1965), with somereservations, referred Megapontius to the family Artotrogidae sensu Eiselt (1961). Heptner (1968)described a new species, M. pleurospinosus, and erected a new family the Megapontiidae for thegenus. Although Megapontius is now recognized as a synonym of Hyalopontius the family name isunchanged as it was based on a generic name which was valid at the time it was proposed. 244 G. A. BOXSHALL Key to species of HYALOPONTIUS (females only) 1 Outer margin spine present on exopod segment 1 of leg 1 3 Outer margin spine absent from exopod segment 1 of leg 1 2 2 Exopod segment 3 of leg 2 with 2 outer margin spines H. alatus n. sp. Exopod segment 3 of leg 2 with 3 outer margin spines . . . . H. hulsemannae n. sp. 3 Distal segment of second antenna with lateral seta situated about 33% of distance along margin; outer margin spine present on exopod segment 2 of leg 1 4 - This seta situated within proximal 25% of margin; outer margin spine absent from exopod segment 2 of leg 1 5 4 Exopod segment 3 of leg 1 with 2 outer margin spines H. typicus Exopod segment 3 of leg 1 with 3 outer margin spines .... H. pleurospinosus 5 Distal seta on lateral margin of leg 5 free segment shorter than segment . . H. cinctus n. sp. - This seta longer than segment 6 6 Exopod segment 3 of leg 2 with 2 outer margin spines; lateral setae on caudal rami situated in proximal one-third of ramus H. spinatus n. sp. - Exopod segment 3 of leg 2 with 3 outer margin spines; lateral setae on caudal rami in distal one-third of ramus 7 7 Body length greater than 7 mm, body squat, about 2-9 times longer than greatest width; exopod of second antenna about 4-6 times longer than wide .... H. enormis n. sp. - Body length less than 6 mm, body about 4-3 times longer than greatest width ; exopod of second antenna about 2 times longer than wide H. roei n. sp. Hyalopontius typicus Sars, 1909Megapontius gigas Hulsemann, 1965. DIAGNOSIS. Female. Body relatively squat, about 34 times longer than greatest width (Fig. 19A);prosome about 1-8 times longer than urosome. Rostrum rounded at apex. Epimeral plates of freethoracic somites 2 and 3 pointed but not markedly produced posteriorly. Relative lengths ofurosome somites and caudal rami 18 : 27 : 12 : 6 : 14 : 23; first urosome somite without additionalspinose processes near posterior border; dentate hyaline membrane absent from posterior border.Posterior border of genital complex with dentate hyaline membrane. Caudal ramus about3-3-2 times longer than wide; lateral setae in distal half of ramus. Relative lengths of first antenna segments 19:2:2:2:3:5:4:7:8:11: 37 (Fig. 19C).Second antenna (Fig. 19D) exopod 1-9 times longer than wide; endopod 2-segmented with lateralspine on distal segment strongly developed and located about 35-38 % of distance along segment;terminal claw longer than rest of appendage. Maxilliped segments 1 and 2 incompletely separated,distal segment with long terminal claw, a small naked subapical seta and a lateral seta, relativelengths of these 3 elements 61 : 7 : 32 respectively. Legs 1-4 armature formula as for generic diagnosis except: Exopod Legl 1-1; 1-1; 11,2,3Leg 2 1-1; 1-1; 111,1,5Leg 3 1-1; 1-1; 11,1,5 Leg 5 basal segment with small inner spinose process (Fig. 19E); free segment with 1 long apicaland 2 medium-length lateral setae. Body length of female 4-87-5-3 mm. Male. Body similar to that of female; relative lengths of urosome somites and caudal ramus16 : 13 : 15 : 12 : 7 : 15 : 22 (Fig. 19F). Appendages as in female (Figs 19H, I). Leg 6 (Fig. 19J) asmall projection bearing a long outer plumose seta, arid two inner, subequal spinules. Body length of males 4-6-5-05 mm. MATERIAL EXAMINED. 18 ?$. 7 $$: N.E. Atlantic Ocean 44 N 12 W, 'Discovery' Stns 8508 78(7 ??) and 8509 20 (1 1 ?$, 7 &?). BM(NH) registration numbers 1977.302-31 1 (?) and 1977.312-318 (<?). PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 245 Fig. 19 Hyalopontius typicus: A, female; B, anterior portion of urosome; C, first antenna; D,second antenna; E, fifth leg; F, male urosome; G, caudal ramus; H, maxilliped; I, fifth leg; J,sixth leg. Scales 0-5 mm unless otherwise indicated. 246 G. A. BOXSHALL REMARKS. The type material of H. typicus could not be located. It is not in the collections of theMusee Oceanographique de Monaco where the other material described in the same paper(Sars, 1909) is stored (Testa, pers. comm.). The present 'Discovery' material is identified as H.typicus because of the agreement in size and body proportions with the specimen figured by Sars(1909), and because of the position of the lateral spine on the distal segment of the second antenna.This spine was described by Sars as being in the middle of the segment but his figure shows it tobe rather more proximal in position. The position of the lateral spine in the 'Discovery' material,at 35-38 % of the distance along the margin of this segment, is sufficiently similar for these speci-mens to be regarded as conspecific with Sars' material. In contrast, the six new species of Hyalo-pontius described below have the lateral seta on the second antenna situated within the proximalquarter (25 %) of the distal segment. There are no significant differences between the material described above as H. typicus andMegapontius gigas Hulsemann, 1965, which is thus regarded as a synonym. Hyalopontius hulsemannae sp. nov. DIAGNOSIS. Female. Body slender (Fig. 20A), about 4 times longer than greatest width; prosomeabout 1-3 times longer than urosome. Rostrum rounded at tip (Fig. 20B). Epimeral plates of freethoracic somite 2 pointed but not markedly produced ; those of free thoracic somite 3 producedposteriorly into a slender projection extending almost as far as the posterior border of the firsturosome somite (Fig. 20C). Relative lengths of urosome somites and caudal ramus 14: 31 : 15 :8 : 20 : 12. Dentate hyaline membrane present along posterior margins of urosome somites 1-4.First urosome somite with 2 small spinose processes dorso-laterally near posterior border. Caudalramus about 2-1 times longer than wide; lateral setae in distal half of ramus (Fig. 20D). Relative lengths of first antenna segments; 19 : 2 : 2 : 2 : 2 : 5 : 4 : 9 : 10 : 10 : 35 (Fig. 20E).Second antenna (Fig. 20F) exopod about 2 times longer than wide; lateral spine on distal endopodsegment small, unilaterally plumose and situated about 7 % of the distance along segment. Mandible(Fig. 20G) with reduced number of dentate projections at tip. Maxilliped (Fig. 20H) segments 1and 2 distinctly divided ; relative lengths of terminal claw, hirsute subapical seta and naked lateralseta 77 : 7 : 16: respectively. Legs 1-4 armature formula as for generic diagnosis except: Exopod Legl 0-1; 0-1; 11,2, 3Leg 2 1-1; 1-1; 111,1,5Leg 3 1-1; 1-1; 11,1,5 Leg 5 (Fig. 201) bearing a small blunt inner process on basal segment; free segment with longapical and 2 medium-length lateral setae.Body length of holotype $ 5-03 mm. MATERIAL EXAMINED. Holotype ?: N.E. Atlantic Ocean 20 N 21 W, 'Discovery' Stn 9541 22.BM(NH) registration number 1977.322. REMARKS. The species is named after Kuni Hulsemann who provided the first well-illustratedaccount of a species in this genus. This species can be distinguished from other species, exceptH. alatus n. sp., by the absence of an outer margin spine from exopod segment 1 of leg 1. It differsfrom H. alatus primarily in the position of the lateral spine on the distal segment of the secondantenna, the degree of expansion of the epimeral plates of free thoracic somites 2 and 3 and thepossession of 3 outer margin spines on exopod segment 3 of leg 2 (as compared to 2 in H. alatus). Hyalopontius alatus sp. nov. DIAGNOSIS. Female. Body slender (Fig. 21 A), about 5-2 times longer than greatest width; prosomeabout 1-3 times longer than urosome. Rostrum rounded at apex. Epimeral plates of free thoracicsomite 2 produced, those of somite 3 markedly produced posteriorly and expanded laterally PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 247 Fig. 20 Hyalopontius hulsemannae n. sp., holotype female: A, dorsal; B, rostrum; C, anteriorportion of urosome; D, caudal ramus, lateral; E, first antenna; F, second antenna; G, tip ofmandible; H, maxilliped; I, fifth leg. Scales 0-5 mm Unless otherwise indicated. 248 G. A. BOXSHALL Fig. 21 Hyalopontius alatus n. sp., holotype female: A, dorsal; B, anterior portion of urosome;C, caudal ramus; D, second antenna; E, maxilliped; F, first leg; G, second leg; H, fifth leg. Scales0-5 mm unless otherwise indicated. PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 249 (Fig. 2 IB). Relative lengths of urosome somites and caudal ramus 16:32: 15: 10: 12: 15.Dentate hyaline membrane present on posterior margins of urosome somites 1-4. First urosomesomite with 2 small spinose processes dorso-laterally near posterior border. Caudal ramus(Fig. 2 1C) about 2-8 times longer than wide; lateral setae in distal half of ramus. First antennae incomplete on both sides. Second antenna (Fig. 2 ID) exopod about 2 timeslonger than wide ; lateral spine on distal endopod segment situated about 1 5 % of distance alongsegment; terminal claw much longer than rest of appendage. Maxilliped (Fig. 2 IE) segments 1and 2 distinctly divided ; relative lengths of terminal claw, hirsute subapical seta and naked lateralseta 81:6:13 respectively. Legs 1-4 (Figs 2 IF, G) armature formula as for generic diagnosis except: Exopod Leg 1 0-1 ; 0-1 ; II, 2, 3Leg 2 1-1; 1-1; 11,1,5Leg 3 1-1; 1-1; 11,1,5 Leg 5 (Fig. 21H) with medium-sized spinose process on basal segment; distal seta on lateralmargin of free segment shorter than the segment.Body length of holotype $ 4-16 mm. MATERIAL EXAMINED. Holotype <j>: N.E. Atlantic Ocean. 'Discovery' Stn 9541 24. BM(NH)registration number 1977.323. REMARKS. The specific name refers to the conspicuous wing-like expansion of the epimeral platesof free thoracic somite 3. This character, together with the armature formula of legs 1 and 2 andthe position of the lateral spine on the distal segment of the second antenna, enables H. alatus tobe distinguished from other species. Hyalopontius spinatus sp. nov. DIAGNOSIS. Female. Body slender (Fig. 22A), about 5-1 times longer than greatest width; prosomeabout 1-2 times longer than urosome. Rostrum truncate at apex (Fig. 22D). Epimeral plates offree thoracic somites 1 and 2 markedly produced posteriorly, those of somite 3 pointed but notmarkedly produced. Relative lengths of urosome somites and caudal ramus 14: 32: 14:9: 11: 20.First urosome somite with a pair of dorso-lateral spinose processes near the posterior border(Figs 22B, C); dentate hyaline membrane present along posterior margins of urosome somites1-4. Caudal ramus about 4-4 times longer than wide; lateral setae situated in proximal half oframus. Relative lengths of first antenna segments 17 : 1 : 1 : 2 : 2 : 5 : 3 : 10 : 12 : 13 : 34 (Fig. 22F);segmental armature as in generic diagnosis but with additional seta on segment II. Second antenna(Fig. 22F) exopod about 2-2 times longer than wide, lateral spine on distal segment small andsituated about 10% of distance along segment; terminal claw much longer than rest of appendage.Mandible (Fig. 22G) with two areas of dentate projections. First maxilla (Fig. 22H) and secondmaxilla (Fig. 221) as in other species of genus. Basal segment of maxilliped (Fig. 22J) with 2 strongprocesses on medial surface; relative lengths of terminal claw, hirsute subapical seta and nakedlateral seta 83 : 8 : 9 respectively. Legs 1-4 (Figs 22K, L) armature formula as for generic diagnosis except: Exopod Legl I*-l; 0-1; 11,2,3Leg 2 1-1; 1-1; 11,1,5Leg 3 1-1; 1-1; 11,1,5 * This spine very small. Leg 5 (Fig. 22M) with large blunt inner process on basal segment; free segment with long apicaland 2 medium-length lateral setae.Body length of holotype $ 4 mm. 250 G. A. BOXSHALL Fig. 22 Hyalopontius spinatus n. sp., holotype female: A, dorsal; B, anterior portion of urosome,dorsal; C, same, lateral; D, rostrum; E, first antenna; F, second antenna; G, mandible; H, firstmaxilla; I, second maxilla; J, maxilliped; K, first leg; L, second leg; M, fifth leg. Scales (M mmunless otherwise indicated. PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 251 MATERIAL EXAMINED. Holotype ?: N.E. Atlantic Ocean 20 N 21 W, 'Discovery' Stn 9541 18.BM(NH) registration number 1977.271. REMARKS. The specific name refers to the spinose processes formed by the development of theepimeral plates of free thoracic somites 1 and 2. This character, together with the armatureformula of legs 1-4 and the position of the lateral setae of the caudal ramus in the proximal halfof the ramus, serves to separate H. spinatus from other species. Hyalopontius voei sp. nov. DIAGNOSIS. Female. Body moderately elongate (Fig. 23A), about 4-3 times longer than greatestwidth; prosome about 1-3 times longer than urosome. Rostrum rounded at apex. Epimeral platesof free thoracic somites pointed but not markedly produced. Relative lengths of urosome somitesand caudal ramus 15 : 32 : 15 : 9 : 14 : 15. Dentate hyaline membrane present on posterior marginsof urosome somites 1-4. First urosome somite with 2 small dorso-lateral processes near posteriormargin (Fig. 23B). Caudal ramus about 2-6 times longer than wide; lateral setae in distal half oframus. Relative lengths of first antenna segments 19 : 1 : 2 : 2 : 2 : 5 : 4 : 11 : 10 : 12 : 32 (Fig. 23C).Second antenna (Fig. 23E) exopod about 2 times longer than wide; distal segment of endopodwith lateral spine situated about 21 % of distance along segment; terminal claw longer than restof appendage. Mandible (Fig. 23F) with complex tip comprising a row of dentate projections, ablade-like process and an apical portion. First maxilla (Fig. 23G) as in other species of genus.Basal segment of maxilliped (Fig. 23H) with 3 small bumps proximally on inner surface and notdistinctly separated from segment 2; relative lengths of terminal claw, hirsute subapical seta andnaked lateral seta 83 : 6 : 11 respectively. Legs 1-4 (Fig. 231) armature formula as for generic diagnosis except : Exopod Legl 1-1; 0-1; 11,2,3Leg 2 1-1; 1-1; 111,1,5Leg 3 1-1; 1-1; 11,1,5 Leg 5 (Fig. 23 J) with large inner spinose process on basal segment; free segment with longapical seta and long proximal seta on lateral margin, distal seta just longer than segment.Body length of holotype $ 5 mm. MATERIAL EXAMINED. Holotype $: N.E. Atlantic Ocean, 'Discovery' Stn 9131 23. BM(NH)registration number 1977.320. REMARKS. This species is named after Dr Howard Roe who found most of the new Hyalopontiusmaterial described in this account. It can be distinguished by the combination of the followingcharacters; the body proportions, the absence of marked epimeral plates, the position of thelateral spine at 21 % of the distance along the distal segment of the second antenna endopod andthe armature formula of legs 1-4. Hyalopontius cinctus sp. nov. DIAGNOSIS. Female. Body slender (Fig. 24A), about 4-7 times longer than greatest width; prosomeabout 1 -3 times longer than urosome. Rostrum rounded at apex. Epimeral plates of free thoracicsomite 2 slightly produced posteriorly; those of somite 3 also produced posteriorly but not reach-ing as far as posterior border of first urosome and not expanded laterally (Fig. 24B). Relativelengths of urosome somites and caudal ramus 14 : 37 : 14 : 9 : 14 : 12. Dentate hyaline membranespresent around posterior borders of urosome somites 1-4. First urosome somite with a pair oflarge blunt processes situated dorso-laterally near posterior margin (Fig. 24B). Caudal ramus(Fig. 24C) about 2-4 times longer than wide; lateral setae in distal half of ramus. Fig. 23 Hyalopontius roei n. sp., holotype female: A, dorsal; B, anterior portion of urosome; C,first antenna; D, spine from first antenna seg. 7; E, second antenna; F, tip of mandible; G, firstmaxilla; H, maxilliped; I, first leg; J, fifth leg. Scales 0-5 mm unless otherwise indicated. PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 253 Fig. 24 Hyalopontius cinctus n. sp., holotype female: A, dorsal; B, anterior portion of urosome;C, caudal ramus; D, first antenna; E, spines from first antenna segs 6 & 7; F, second antenna;G, maxilliped; H, fifth leg. Scales 0-5 mm unless otherwise indicated. 254 G. A. BOXSHALL Relative lengths of first antenna segments 20 : 1 : 2 : 2 : 2 : 5 : 4 : 10 : 11 : 11 : 32 (Fig. 24D).Second antenna (Fig. 24F) robust; exopod about 1-9 times longer than wide; distal segment ofendopod with lateral spine positioned about 22 % of distance along segment; terminal claw longerthan rest of appendage. Segments 1 and 2 of maxilliped (Fig. 24G) distinctly separated; relativelengths of terminal claw, hirsute subapical seta and naked lateral seta 81 : 6 : 13 respectively. Legs 1-4 armature formula as for generic diagnosis except: Exopod Legl 1-1; 0-1; 11,2,3Leg 2 1-1; 1-1; II-III*, I, 5Leg 3 1-1; 1-1; 11,1,5 * Two spines are present on one member and three on the other. Leg 5 (Fig. 24H) with small inner process on basal segment; free segment with long apical seta,medium length proximal seta and very short distal seta on lateral margin.Body length of holotype $ 4-94 mm. MATERIAL EXAMINED. Holotype $: N.E. Atlantic Ocean 20 N 21 W, 'Discovery' Stn 9131 23.BM(NH) registration number 1977.321. REMARKS. The specific name of this species alludes to the distinctive leg 5. The short distal setaon the lateral margin of the free segment of leg 5 serves to distinguish H. cinctus from the otherdescribed species of the genus. Hyalopontius enormis sp. nov. DIAGNOSIS. Female. Body large, squat in appearance (Fig. 25A); about 2-9 times longer thangreatest width; prosome about 2 times longer than urosome. Rostrum rounded at apex. Epimeralplates of free thoracic somites hardly produced at all. Relative lengths of urosome somites andcaudal ramus 17 : 27 : 14 : 8 : 14 : 20. Smooth hyaline membranes present on posterior margins ofurosome somites 1-4. First urosome somite without spinose processes. Genital complex verybroad (Fig. 25B), only 1-1 times longer than greatest width. Caudal ramus (Fig. 25C) about 2-5times longer than wide; lateral setae in distal half of ramus. Relative lengths of first antenna segments 19:1:1:2:2:6:3:8: 10 :13: 35 (Fig. 25D).Second antenna (Fig. 25E) robust, first endopod segment fused to basipod; exopod about 4-6times longer than wide ; lateral seta on distal segment of endopod positioned 20 % of distance alongsegment; terminal claw shorter than rest of appendage. Mandible (Fig. 25F) with complex tipcomprising dentate margin, trilobed apical portion and hirsute lateral portion. First maxilla(Fig. 25G) and second maxilla (Fig. 25H, I) as in other members of genus. Maxilliped (Fig. 25J)with segments 1 and 2 fused; relative lengths of terminal claw, hirsute subapical seta and nakedlateral seta 74 : 5 : 21 respectively. Legs 1-4 (Figs 25K, L) as for generic diagnosis except: Exopod Legl 1-1; 0-1; 11,2,3Leg 2 1-1; 1-1; HI,I,5Leg 3 1-1; 1-1; 11,1,5 Leg 5 (Fig. 25 M) with small inner process on basal segment; free segment with long apical setaand 2 lateral setae of medium length.Body length of holotype $ 7-6 mm. MATERIAL EXAMINED. Holotype $: N.E. Atlantic Ocean 20 N 21 W, 'Discovery' Stn 9131 23.BM(NH) registration number 1977.319. REMARKS. This is the largest known planktonic siphonostomatoid and can be distinguished fromother species of the genus by its body proportions, the shape of the genital complex and theelongate exopod of the second antenna. PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 255 Fig. 25 Hyalopontius enormis n. sp., holotype female: A, dorsal; B, anterior portion of urosome;C, caudal ramus; D, first antenna; E, second antenna; F, tip of mandible; G, first maxilla; H,second maxilla; I, tip of second maxilla; J, maxilliped; K, first leg; L, second leg; M, fifth leg.Scales O5 mm unless otherwise indicated. MORMONILLOIDA The genus Mormonilla was first described by Giesbrecht in 1891, but because it exhibits a com-bination of podoplean and gymnoplean characters its position in the classification of the Copepodais still uncertain. Giesbrecht (1891, 1892) placed it in a separate family, the Mormonillidae,within the Podoplea Ampharthandria, which also included the families Cyclopidae, Harpacticidae 256 G. A. BOXSHALL and Monstrillidae. The latter three families were raised to subordinal level by Sars (1901). Sars(1902) placed Mormonilla in the family Tortanidae of the Calanoida, but later (1913) changedthis opinion, and stated that the systematic position of the genus is very doubtful though it mayperhaps be regarded as the type of a very anomalous family of the gnathostomous Cyclopoida.Few authors have considered the systematic position of the Mormonillidae since Sars. Rose (1933)adopted a cautious approach and placed the Mormonillidae in the Podoplea, but did not assignthis family to any of the existing suborders. In a recent work which deals with copepod systematics (Kabata, 1979), a more natural arrange-ment of the podoplean line is attained with the recognition of six orders: Harpacticoida,Monstrilloida, Misophrioida, Siphonostomatoida, Poecilostomatoida and Cyclopoida. The Mor-monillidae appear to be more closely related to the Misophrioida than to any other order, inpossessing a podoplean arrangement of the body somites and typically gymnoplean mouthparts.However, Mormonilla differs from the two genera that comprise the aberrant Misophrioida(Misophria Boeck and Benthomisophria Sars) in the absence of a 'heart', the small number ofsegments in the first antenna and the complete absence of the fifth leg. Mormonilla resembles thecyclopoid genus Oithona Baird 1843 in general body facies and the structure of the first antenna,but the presence of a well-developed exopod on the second antenna suggests that the sharedcharacters owe more to convergence than to a true phylogenetic relationship. It is therefore pro-posed to raise the family Mormonillidae to ordinal level. Family MORMONILLIDAE Genus MORMONILLA Giesbrecht, 1891 DIAGNOSIS. Body slender, cyclopiform (Fig. 26A); with 5-segmented prosome and 4-segmentedurosome. Genital complex with paired ventral genital openings and spinose areas laterally.Caudal ramus longer than urosome, bearing 6 armature elements. First antenna 3- or 4-segmented.Second antenna (Fig. 26D) with 8-segmented exopod and 2-segmented endopod. Mandible(Fig. 26E) blade with strongly incised teeth; palp comprising large basis fused to endopod and1 -segmented exopod; both rami armed with 6 plumose setae. First maxilla (Fig. 26F) with well-developed basis; gnathobase small but distinct and bearing 8 armature elements; both exopodand endopod 1 -segmented, armed with 6 and 8 setae respectively. Second maxilla (Fig. 26G)elongate, 5-segmented; proximal segment with 3 endites, second segment with 1 endite and anisolated seta; remaining 3 segments with 1, 1 and 4 armature elements. Maxilliped 2- or 3-seg-mented. Legs 1-4 biramous; leg 1 with 2- or 3-segmented rami; leg 2 exopod 2- or 3-segmented,endopod 1- or 2-segmented; leg 3 with 1 segmented endopod and 2- and 3-segmented exopod;leg 4 with 1 -segmented endopod and 2-segmented exopod. Legs 5 and 6 absent. Male unknown. TYPE-SPECIES. Mormonilla phasma Giesbrecht, 1891. Mormonilla phasma Giesbrecht, 1891 DIAGNOSIS. Widest part of genital complex in anterior third (Figs 26B, C). Lateral seta on caudalramus situated about 33 % of distance along ramus (Fig. 26A). First antenna 3-segmented, relativelengths of segments about 56 : 28 : 16. Maxilliped (Fig. 26H) 2-segmented; proximal segment with6 medial margin setae, distal segment with 7 setae. Leg 1 (Fig. 261) with spinose inner projections on coxa, basis and endopod segments; bothrami 2-segmented; legs 2-4 with 2-segmented exopods and 1 -segmented endopods; armatureformula as follows. PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 257 Coxa Basis Endopod0-0 0-0 0-0; 0, 2, 20-0 0-0 0, 2, 10-0 0-0 0, 2, 10-0 0-0 0, 2, 1 LeglLeg 2Leg3Leg 4 Body length of female from 1-58 to 1-73 mm. MATERIAL EXAMINED. 1507 ?$: N.E. Atlantic, 18N 25 W, 'Discovery' Stn 7089. BM(NH)registration numbers 1977.272-281. Exopod1-0; III, 2, 30-0; I, 1, 50-0; 0, 1, 40-1; 0,1,3 Fig. 26 Mormonilla phasma : A, female; B, genital complex, lateral; C, same, ventral; D, secondantenna; E, mandible; F, first maxilla; G, second maxilla; H, maxilliped; I, first leg; J, second leg;K, third leg; L, fourth leg. Scales 0-1 mm unless otherwise indicated. 258 G. A. BOXSHALL REMARKS. This species is most readily distinguished by the position of the lateral seta on the caudalramus when sorting through large samples of Mormonilla. Other significant differences are foundin the segmentation of the first antennae and legs 1-3. Mormonilla minor Giesbrecht, 1891 Mormonilla minor Giesbrecht, 1891 : 474.Mormonilla polaris Sars, 1900 : 120-126, pi. XXXIV.Mormonilla atlantica Wolfenden, 1905 : 16. DIAGNOSIS. Widest part of genital complex about at mid-point (Fig. 27B). Lateral seta on caudalramus located about 16 % of distance along ramus (Fig. 27A). First antenna 4-segmented, relativelengths of segments about 25 : 28 : 25 : 22 (Fig. 27C). Maxilliped (Fig. 27D) indistinctly 3-seg-mented; proximal segment with 7 setae on medial margin, middle segment with 1 seta and distalsegment with 5 setae. Leg 1 (Fig. 27E) with fringes of strong setules on inner margins of coxa,basis and endopod; both rami usually 3-segmented; leg 2 (Fig. 27F) with 3-segmented exopod and2-segmented endopod; leg 3 with 3-segmented exopod and 1 segmented endopod; leg 4 with2-segmented exopod and 1 -segmented endopod. Armature formula as follows: Coxa Basis Endopod Exopod Leg 1 0-0 0-0 0-0; 0-0; 0, 2, 1 1-0; 1-1; II, 1, 3 Leg 2 0-0 0-0 0-0; 0,2,1 0-0; 0-1; I, 1, 4 Leg 3 0-0 0-0 0, 2, 1 0-0; 0-1; 0, 1, 3 Leg 4 0-0 0-0 0,2, 1 0-1; 0, 1,3 Body length of female from 1-2 to 1-38 mm. MATERIAL EXAMINED. 274?$: N.E. Atlantic Ocean, 18 N 25 W, 'Discovery' Stn 7089. BM(NH)registration numbers 1977.282-291. REMARKS. The segmentation of the first pair of swimming legs is rather variable with the leg 1endopod being either 2- (Giesbrecht, 1891, 1892) or 3-segmented (Sars, 1900; Wolfenden, 1905).This variation appears to reflect merely the degree of separation of the two distal segments and isnot regarded as significant (Farran, 1908). Species depth distributions The depth distribution data for all of the species recorded from the 'Discovery' Station 7089Day and Night series are given in Table 3. The vertical migration patterns of the more abundantspecies are discussed below. Aegisthus mucronatus: During the day female A. mucronatus were found between 210 and790 m and over 80% of the population was concentrated at 210-290 m. At night the depth rangewas greater, 25-785 m, and there was some evidence of both upward and downward night scatter-ing as 89% of the population was distributed between 110 and 400 m. The data for the males(Table 3) also provide some evidence of an upward vertical migration at night. Aegisthus aculeatus: This species was distributed quite uniformly between 700 and 1220 m inthe daytime. During the night the depth range was virtually the same although a small number ofspecimens was recorded at 505-700 m. The population appeared to be more concentrated atnight as 86% of individuals were found between 800 and 1010 m. A. aculeatus was the dominantharpacticoid between 700 and 1250 m whilst its congener, A. mucronatus, was dominant in the11 0^500 m depth range. There was little vertical overlap between the distribution of these twospecies. Miracia efferata: M. efferata was found only within the upper 100 m of the water column bothday and night and there is little evidence of any diurnal change in depth distribution. Other harpacticoid species: The remaining species occurred in small numbers within the follow-ing depth ranges: Macrosetella gracilis, 55-300 m; Clytemnestra scutellata, 10-60 m; Microsetella PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 259 Fig. 27 Mormonilla minor: A, female urosome; B, genital complex, ventral; C, first antenna;D, maxilliped; E, first leg; F, second leg. Scales 0*1 mm. norvegica, 0-290 m; Neotisbella gigas, 300-900 m; Volkmannia forficula, 4 1 0-900 m; Bathyidiaremota 1000-1250 m and Volkmannia attenuata 3760-3920 m. Pontoeciella abyssicola: Females were recorded between 112 and 600m during the day, withabout 57% of the population distributed above 400 m. At night the depth range was 110-700 mand over 76 % of the population was concentrated above 400 m. This indicates that an upwardvertical migration of at least part of the population had occurred. Other siphonostomatoid species: Small numbers of Ratania flava were found between 20 and200 m. The species of Hyalopontius were recorded from the following depths: H. typicus, 2500-3100 m and 3000-3500 m; H. hulsemannae, 3740-3870 m; H. alatus, 3000-3500 m; H. spinatus,3830-4060 m; H. roei, 3000-3500 m; H. cinctus, 3000-3500 m and H. enormis 3000-3500 m. Mormonilla phasma: This species occurred primarily between 410 and 1250 m, with only occa-sional specimens taken in shallower hauls. The day and night depth distributions were similarwith between 70 and 75 % of the population concentrated at 410-700 m in the shallow mesopelagiczone. 260 G. A. BOXSHALL PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 261 w i* ^ 5 S " o B 5 -2 111- -Q 60 ^s ?s * 3<oa J *0 \ \ \ \ \ \ | | I I VO I I I I I I I II I <S I <N I I I I I I I S ' 1 1 pi 1 1 1 1 1 1 1 1 1 | | | I I I I I I 00 I I I I 00| | | | I I 1 I I 00 1 I I I 00 I vo oo I I i I I S I I I I I I I I I "* I i i i i MS i I ^j I o | | | | OO I SO VO Tt fS ^O r-l 0\ 00 >0 ^ => <N Q I 00 I I I I 10 262 G. A. BOXSHALL Mormonilla minor : M. minor has an almost identical depth distribution to that of M. phasma.The depth range is basically 410-1220 m with isolated records from shallower hauls. The distribu-tion is slightly more concentrated in the 410-700 m depth zone with between 86 and 95% of thepopulation occurring there. The similarity between the depth distributions of the two species of Mormonilla is remarkablebecause the other two pairs of closely related forms found in the mesopelagic zone (i.e. the twospecies ofAegisthus and the two forms of Oncaea ornata Giesbrecht) both exhibit a marked degreeof vertical segregation (see Boxshall, 1911 a for Oncaea ornata). Acknowledgements I am grateful to Dr Howard Roe (Institute of Oceanographic Sciences) for arranging the loan 01this material and for providing other relevant data. I would also like to thank Dr Roger Lincolnfor reading and commenting on the manuscript and Miss Ann Gurney for her help in the prepara-tion of the manuscript. Dr Brigitte Volkmann (Istituto di Biologia del Mare, Venezia) examinedsome of the tisbid material and I am very grateful for her detailed comments and advice. I wouldalso like to thank Dr G. Deevey for allowing me to examine her specimen of Bathyidia remota. References Baird, W. 1843. Note on the luminous appearance of the sea with descriptions of some of the entomostra-cous insects by which it is occasioned. Zoologist 1 : 55-61. Boeck, A. 1864. Oversigt over de ved Norges kyster iagttagne Copepoder henh0vende tie Calanidernes,Cyclopidernes og Harpacticidernes Familiar. Fork. VidenskSelsk. Krist. 1864: 226-281. Boxshall, G. A. 1977. The planktonic copepods of the northeastern Atlantic Ocean: some taxonomicobservations on the Oncaeidae (Cyclopoida). Bull. Br. Mus. not. Hist. (Zool.) 31 : 103-155. 1977o. The depth distributions and community organization of the planktonic cyclopoids (Crus-tacea : Copepoda) of the Cape Verde Islands region. /. mar. biol. Ass. U.K. 57 : 543-568. Brady, G. S. 1880. A monograph of the free and semiparasitic Copepoda of the British Islands. Ray Society,London. 2: 182 pp. 1883. Report on the Copepoda obtained by H.M.S. 'Challenger' during the years 1873-1876. Rep. sclent. Results. H.M.S. 'Challenger' 1873-1876 Zool 8 (1) : 1-142. & Robertson, R. D. 1873. Contributions to the study of the Entomostraca. 8, On marine Copepoda taken in the west of Ireland. Ann. Mag. nat. Hist. 12 : 126-142.Chappius, P. A. 1936. Brasilianische Ruderfusskrebse (Crustacea, Copepoda) gesammelt von Herrn. Dr. Otto Schubart. IV. Mitteilung. Bui. Soc. Sti. C/ay. 8: 450-461.Glaus, C. 1863. Die Frei Lebenden Copepoden. Leipzig. 230 pp. 1866. Die Copepoden-Fauna von Nizza. Schr. Ges. Bedford, ges. Naturw. Marburg 1-34. 1891. Ueber Goniopelte gracilis, eine neue Peltidie. Arb. zool. Inst. Univ. Wien. 9: 151-162. Dahl, F. 1895. Die Schwarmbildung pelagischer Thiere. Zool. Anz. 18 : 168-171. Dana, J. D. 1848. Conspectus Crustaceorum quae in orbis terrarum circumnavigatione, Carolo Wilkes e classe Reipublicae Foederatae duce, lexit et descripsit Jacobus D. Dana. Proc. Am. Acad. Arts Sci. 1 : 150-154. 1852. Crustacea. U.S. Explor. Exped. 13: 1-38. Deevey, G. B. & Brooks, A. L. 1977. Copepods of the Sargasso Sea off Bermuda: species composition, and vertical and seasonal distribution between the surface and 2000 m. Bull. Mar. Sci. 27 : 256-291.Eiselt, J. 1961. Neubeschreibungen und Revision Siphonostomer Cyclopoiden (Copepoda, Crust.) von der siidlichen Hemisphere nebst Bemerhungen tiber die Familie Artotrogidae Brady 1880. Sber. ost. Akad. Wiss. 170:315-366.Farran, G. P. 1905. Report on the Copepoda of the Atlantic Slope off Counties Mayo and Galway. Rep. Sea Inld. Fish. Ire. 1902-03, Appendix II : 23-52.1908. Second report on the Copepoda of the Irish Atlantic Slope. Scient. Invest. Fish. Brch. Ire. 1906, 2 : 3-104. 1914. Description of a harpacticid copepod parasitic on an Octopus. Ann. Mag. nat. Hist. 13 : 472- 475. 1926. Biscayan plankton collected during a cruise of H.M.S. 'Research' 1900. Part XIV. The Cope-poda. J. Linn. Soc. (Zool.) 36: 219-310. 1929. Copepoda. Nat. Hist. Rep. Br. antarct. Terra Nova Exped. (Zool.} 8 : 203-306. PLANKTONIC COPEPODS OF THE N.E. ATLANTIC 263 1936. Copepoda. Sclent. Rep. Gt. Barrier Reef Exped. 5 (3) : 73-142. Giesbrecht, W. 1891. Elenco die Copepodi pelagici raccolti dal tenente di vascello Gaetano Chierchiadurante il viaggio della R. Corvetta 'Vettor Pisani' negli anni 1882-85, e dal tenenti di vasiello FrancescoOrsini nel Mar Rosso, nel 1884. Att. Accad. naz. Lincei. Re. 7 (10) : 474-481. 1892. Systematik und Faunistik des pelagischen Copepoden des Golfes von Neapel und der angren- zenden Meeresabschnitte. Fauna Flora Golfo Napoli 19 : 1-831. 1895. Mittheilungen uber Copepoden, 10-11. Mitt. Zool. Stn. Neapel. 12: 217-226. Gurney, R. 1927. Zoological Results of the Cambridge Expedition to the Suez Canal, 1924. XXXIII. Report on the Crustacea:- Copepoda (Littoral and Semi-parasitic). Trans, zool. Soc. Lond. 22 (4) : 451- 577.Haq, S. M. 1965. Development of the copepod Enter pina acutifrons with special reference to dimorphism in the male. Proc. zool. Soc. Lond. 144: 175-201.Heptner, M. V. 1968. Description and functional morphology of Megapontius pleurospinosus sp. n. from the Pacific with some remarks on the status of the genus Megapontius within the system of families of Siphonostoma group (Copepoda, Cyclopoida). Zool. Zh. 11 : 1628-1638. [In Russian.]Heron, G. A. & Damkaer, D. M. 1969. Five species of deep-water cyclopoid copepods from the plankton of the Gulf of Alaska. Smithson. Contr. Zool. 20 : 1-24.Hulsemann, K. 1965. A new genus and species of siphonostome cyclopoid copepod from deep North Atlantic waters. Crustaceana 9 : 45-50.Humes, A. G. & Ho, J. S. 1969. Harpacticoid copepods of the genera Porcellidium and Paraidya associated with Hermit crabs in Madagascar and Mauritius. Crustaceana 17 : 113-130.Kabata, Z. 1979. Parasitic Copepoda of British Fishes. Ray Society, London. 459 pp.Klie, W. 1913. Die Copepoda Harpacticoida des Gebietes der Unter- und Aussenweser und der Jade. Schr. Ver. Natur. Unterw. 3 : 1-49.Kreyer, H. 1842. Crustaces. Atlas, pis. 41-43 (in: Gaimard, P. Voyages de la Commission scientifiques du Nord en Scandinavie, en Lapone, au Spitzberg et aux Feroe pendant les annees 1838, 1839 et 1840 sur la Corvette l La Recherche'. Paris). Lang, K. 1948. Monographic der Harpacticiden. Hakan Ohlsson, Lund. 1682 pp.Lilljeborg, W. 1853. De crustaceis ex ordinibus tribus: Cladocera, Ostracoda et Copepoda, in Scania ocurrentibus. Lund. 222 pp. Mori, T. 1964. The pelagic Copepoda from the neighbouring waters of Japan. Tokyo. 145 pp.Norman, A. M. 1868. Shetland final dredging report. Part II. On the Crustacea, Tunicata, Polyzoa, Echinodermata, Actinozoa and Porifera. Rep. Br. Ass. Advmt. Sci. 1868 : 297. 1903. New generic names for some Entomostraca and Cirripedia. Ann. Mag. not. Hist. 11 : 367-369. Owre, H. B. & Foyo, M. 1967. Copepods of the Florida Current. Fauna carib. No. 1, Crustacea, Pt. 1, Copepoda: 137 pp. Poppe, S. A. 1891. Beitrag zur Kenntniss der Gattung Clytemnestra Dana. Abh. Ver. Bremen 12 : 131-142.Rose, M. 1929. Copepodes pelagiques particulierement de surface provenant des campagnes scientifiques du Prince Albert ler de Monaco. Result. Camp, sclent. Prince Albert 1, 78 : 1-123. 1933. Copepodes pelagiques. Fame Fr. 26 : 1-374. Saraswathy, M. 1961. Observations on the genus Ratania (Copepoda) with a description of the type species. Bull. Cent. Res. Inst. Univ. Travancore 8 : 141-146. Sars, G. O. 1900. Crustacea. Sclent. Results Norw. N. polar Exped. 1893-1896 1 (5) : 1-141.1901. An account of the Crustacea of Norway. IV. Copepoda Calanoida. Bergen Museum. Pts. I & II : 1-28.1902. An account of the Crustacea of Norway. IV. Copepoda Calanoida. Bergen Museum. Pts. VII- VIII : 73-96.1905. An account of the Crustacea of Norway. V. Copepoda Harpacticoida. Bergen Museum. Pts. DC-X: 109-132,1909. Note preliminaire sur trois formes remarquables de Copepodes, provenant des Campagnes de S.A.S. le Prince Albert de Monaco. Bull. Inst. Oceanogr. Monaco 147 : 1-8.1913. An account of the Crustacea of Norway. VI. Copepoda Cyclopoida. Bergen Museum. Pts. I & II : 1-32.1916. Liste systematique des Cyclopoides, Harpacticoides et Monstrilloides recueillis pendant les campagnes des S.A.S. le Prince Albert de Monaco, avec descriptions et figures des especes nouvelles. Bull. Inst. oceanogr. Monaco 323 : 1-15. 1921. An account of the Crustacea of Norway. VII. Copepoda supplement. Bergen Museum. 121 pp. Scott, A. 1909. The Copepoda of the Siboga Expedition, Part I. Free swimming, littoral and semi-parasiticCopepoda. Siboga Exped. 29a : 1-323. 264 G. A. BOXSHALL Scott, T. 1894. Report on Entomostraca from the Gulf of Guinea, collected by John Rattray, B.Sc. Trans.Linn. Soc. Lond. Zool. ser. 2, 6 (1) : 1-161. Sewell, R. B. Seymour. 1940. Copepoda Harpacticoida. Sclent. Rep. John Murray Exped. (Zool.) 7(2): 117-382. 1947. The freeswimming plankton Copepoda. Systematic account. Sclent. Rep. John Murray Exped. (Zool.) 8 (1) : 1-303. Ummerkutty, A. N. P. 1968. Studies on the crustacean fauna of the Mysore coast 2. Description of thecopepod Danodes panikkari n. sp. with remarks on the systematic position of the genus DanodesWilson. Crustaceana 15 : 298-304. Wells, J. B. J. 1970. Copepoda - 1, suborder Harpacticoida. Fich. Ident. Zooplancton 133 : 1-7. Wilson, C. B. 1924. New North American parasitic copepods, new hosts, and notes on copepod nomen-clature. Proc. U.S. natn. Mus. 64 : 1-22. 1942. The copepods of the plankton gathered during the last cruise of the Carnegie. Scient. Results Cruise VII Carnegie 1 : 1-237. Wolfenden, R. N. 1905. Plankton Studies, preliminary notes upon new or interesting species. Part i. Copepoda.London & New York. 24 pp. Yea t man, H. C. 1962. The problem of dispersal of marine littoral copepods in the Atlantic Ocean, in-cluding some redescriptions of species. Crustaceana 4 : 253-272. 1963. Some redescriptions and new records of littoral copepods for the Woods Hole, Massachusetts Region. Trans. Am. microsc. Soc. 82 : 197-209. Manuscript accepted for publication 20 March 1978 British Museum (Natural History)Monographs & Handbooks The Museum publishes some 10-12 new titles each year on subjectsincluding zoology, botany, palaeontology and mineralogy.Besides being important reference works, many, particularly amongthe handbooks, are useful for courses and students' backgroundreading. Lists are available free on request to : Publications Sales British Museum (Natural History) Cromwell Road London SW7 5BD Standing orders placed by educational institutions earn a discountof 10% off our published price. Titles to be published in Volume 35 A revision of the 'acaecate' earthworms of the Pheretima group(Megascolecidae: Oligochaeta) : Archipheretima, Metapheretima,Planapheretima, Pleionogaster and Polypheretima. By E. G. Easton. Miscellanea The planktonic copepods of the northeastern Atlantic Ocean:Harpacticoida, Siphonostomatoida and Mormonilloida. By G. A.Boxshall. Towards a phyletic classification of the 'genus' Haplochromis (Pisces,Cichh'dae) and related taxa. Part I. By Peter Humphry Greenwood. A revision of the British species of the genus Phthiracarus Perty, 1841(Cryptostigmata: Euptyctima). By B. W. Parry. Type set by John Wright & Sons Ltd, Bristol and Printed by Henry Ling Ltd, Dorchester Bulletin of the British Museum (Natural History) Towards a phyletic classification of the'genus' Haplochromis (Pisces, Cichlidae) arrelated taxa.Parti. Peter Humphry Greenwood Zoology series Vol 35 No 4 31 May 1979 The Bulletin of the British Museum (Natural History), instituted in 1949, is issued in fourscientific series, Botany, Entomology, Geology (incorporating Mineralogy) and Zoology, andan Historical series. Parts are published at irregular intervals as they become ready. Volumes will contain aboutthree hundred pages, and will not necessarily be completed within one calendar year. Subscription orders and enquiries about back issues should be sent to : Publications Sales,British Museum (Natural History), Cromwell Road, London SW7 5BD, England. World List abbreviation: Bull. Br. Mus. nat. Hist. (Zool.) Trustees of the British Museum (Natural History), 1979 ISSN 0007-1498 Zoology series Vol 35 No 4 pp 265-322British Museum (Natural History)Cromwell RoadLondon SW7 5BD Issued 31 May 1979 Towards a phyletic classification of the 'genus'Haplochromis (Pisces, Cichlidae) and related taxa. Part I. Peter Humphry Greenwood Department of Zoology, British Museum (Natural History), Cromwell Road, London SW7 5BD Contents Introduction 266 Methods and materials 269 Methods 269 Materials 276 Classification 277 Section I .... 278 Haplochromis Hilgendorf . 278 Description ....... ... 278 Contained species ........ 280 Diagnosis and discussion 281 Astatotilapia Pellegrin 281 Description ......... . 281 Contained species 283 Diagnosis and discussion ...... . 284 Astatoreochromis Pellegrin . 285 Discussion . 285 Contained species ........... 286 Ctenochromis PfefTer 287 Description 287 Contained species 289 Diagnosis and discussion ......... 289 Thoracochromis gen. no\. .......... 290 Description 291 Contained species ........... 293 Diagnosis and discussion ...... . 294 Orthochromis Greenwood .......... 295 Synonymy ............ 295 Description ........ ... 296 Contained species ........... 297 Diagnosis and discussion ......... 297 Section 11 299 Serranochromis Regan .......... 299 Subgenus Serranochromis Regan ........ 299 Description ............ 299 Contained species ........... 302 Subgenus Sargochromis Regan ......... 303 Description 303 Contained species ........... 304 Diagnosis and discussion ....... 306 Chetia Trewavas ........... 307 Description 307 Contained species ........... 308 Diagnosis and discussion 308 Bull. Br. Mns. nat. Hist. (Zool.) 35 (4): 265-322 Issued 31 May 1979 265 266 P. H. GREENWOOD Pharyngochromis gen. nov. . ......... 310 Description ............ 310 Contained species ........... 311 Diagnosis and discussion ......... 311 The Angolan Haplochromis species ......... 312 Summary and conclusions .......... 313 Key to the genera 315 Appendix 1 A replacement 'generic' name for the Lake Malawi 'Haplochromis' species . . 317Appendix 2 The taxonomic status of the genus Limnotilapia Regan, 1920 . . . . 317 Acknowledgements ............ 319 References 319 Index 321 Introduction As currently recognized, the genus Haplochromis Hilgendorf encompasses over 300 species, somedoubtless nominal but the majority of apparent biological validity (see Fryer & lies, 1972;Greenwood, 19740). It is the most speciose African taxon in the family Cichlidae and, next to thegenus Sarotherodon has the widest distribution in the continent, extending from Tunisia in thenorth to Namibia (South West Africa) in the south. It is, however, virtually absent from westAfrica, being represented there by only one or two species from Nigeria. Amongst its numbers, indeed contributing the greatest number of species, are the well-knownHaplochromis flocks of Lakes Victoria and Malawi (Trewavas, 1935; Fryer & lies, 1972;Greenwood, 19740), together with the smaller and less studied flocks of Lakes Edward, George,Turkana (Rudolf), Albert and Kivu (see Regan, 19210; Poll, 1932; Trewavas, 1933; Trewavas,1938; Greenwood, 1973, 19746). It is amongst the species of these various lacustrine flocks that one encounters the great rangeof anatomical, dental and morphological differentiation usually associated with the genus. Thefluviatile species appear to be less diversified, but even here there is more diversity than is realizedat first. With this wide range of anatomical and morphological variation it is not surprising that thepresent concept of the genus, both in morphological and in phyletic terms, is very ill-defined. In-deed, the concept of Haplochromis seems to be based entirely on some intuitive appreciation of'overall similarity' amongst its constituent species. There has been, so far, no real attempt totest the validity of the implicit monophyly of these species. The recognizable and often notedintrageneric variability in Haplochromis has, until recently, not been seen as an analytical taxo-nomic tool because thinking amongst systematists working on cichlids has been dominated by a'size of the morphological gap' approach to supraspecific classification. A reappraisal of the situation with this variation seen in terms of derived (apomorph) andprimitive (pleisomorph) character states has not been applied to the genus as a whole (but seeGreenwood, 19740, for the Lake Victoria species). It is this basically Hennigian approach (Hennig,1966) that I have attempted to apply to the problem. Its use, I believe, does allow one to producea more realistic classification of the species now lumped together in Haplochromis, or separatedfrom that genus because of their showing an extreme manifestation of features already indicatedin species still retained in Haplochromis. The taxon Haplochromis was first introduced by Hilgendorf (1888), as a subgenus of Chromis,for his new species aptly named 'obliquidens' (see Greenwood, 19560). The fine, closely packedand multiseriate teeth of ' obliquidens\ with their protracted and obliquely truncate crowns (seeFig. 7B), provided the diagnostic features for Hilgendorf 's subgenus. No further species were added to Haplochromis until Boulenger (1906) elevated the taxon togeneric rank and included in it six new species from Lake Victoria and the Victoria Nile. Boulengergave no reasons for raising Hilgendorf's subgenus to a full genus, nor did he attempt to defineHaplochromis so as to accommodate the new species, none of which had teeth like those of A REVISION OF THE HAPLOCHROMIS GENERIC CONCEPT 267 H. obliquidens. A footnote to the paper (Boulenger, 1906 : 443) might be interpreted as a genericdefinition, but it is completely inadequate and rather confusing, merely noting that '. . . inaddition to the character of the dentition, intermediate between Paratilapia and Tilapia, thefishes of this genus differ from the latter in usually having a considerable portion of the maxillarybone exposed when the mouth is fully closed'. The following year Boulenger (1907 : 495) did provide a formal definition of Haplochromis, inwhich genus he then synonymized Pffefer's (1893) genus Ctenochromis and Pellegrin's (1903)Astatoreochromis (now recognized as a distinct genus, see Greenwood, 1959a; Poll, 1974 andp. 285 below). This definition is, however, very vague and so worded that it is impossible todistinguish Boulenger 's concept of Haplochromis from that of his redefined Paratilapia Bleeker. The situation remained virtually unchanged, except for the addition of several more species,with the publication of the third volume in Boulenger's Catalogue of African Freshwater Fishes(1915) in which he again comments that some Haplochromis species '. . . vary to such an extentin their dentition that [they] might be referred to Tilapia and others to Paratilapia'. Regan's (1920, 19220) fundamental studies on the osteology of African Cichlidae, and hisconsequent revision of Boulenger's genera, resulted in many more species being included inHaplochromis (which then became the '. . . largest African genus', Regan, 1920 : 45). In his 1920paper Regan also defined (in a footnote) several genera which, although apparently related toHaplochromis, differed from that genus in various dental features, both oral and pharyngeal. Surprisingly, in the light of these other generic definitions, Regan was content to include inHaplochromis a majority of species whose dental characters were quite unlike those of the typespecies. In effect, Regan's redefinition of Haplochromis in these and subsequent papers (especiallythose of 192 la & b and 1922a & 6) was only a slight improvement of that provided by Boulenger.Haplochromis remained a polymorphous assemblage of species showing a wide range of dentaland other anatomical peculiarities, only united by having a particular kind of cranial apophysisfor the upper pharyngeal bones. Since a similar apophysis occurs in other taxa defined by Regan,the monophyletic origin of Hapolchromis was not established. That Regan was aware of his system's shortcomings is shown by remarks in his papers on thecichlids of Lakes Malawi (19216) and Victoria (19226). For example, regarding the Haplochromisof Lake Victoria he wrote (Regan, 19226 : 158): 'The species of Haplochromis exhibit almost asgreat a diversity as in Nyassa, yet there are certain features which enable one to say almost at aglance to which lake a species belongs', and on page 160: 'From what has been said above as tothe evolution and relationships of the Cichlidae of Victoria, it will be evident that I do not regardthe classification here proposed as entirely satisfactory'. Regarding the species of Lake Malawi, Regan (19216 : 686) has this to say: '. . . the absence ofevident relationship to species found elsewhere leads to the conclusion that the Nyassa speciesare a natural group and may, perhaps, have evolved in the lake from a single ancestral form'.Regrettably, Regan does not elaborate on his remark about the absence of evident relationshipto species found elsewhere, particularly since a year later he was to place the majority of LakeVictoria species in the same genus. When revising the Lake Victoria species, Regan (19226) divided the Haplochromis into fivesubgenera, Neochromis for //. nigricans and H. nuchisquamulatus, Bayonia for H. xenodon (nowconsidered a synonym of Macropleurodus, see Greenwood, 19566), Haplochromis for H. obliqui-dens, and Ctenochromis for the remaining 42 species. These latter were characterized by theirhaving conical or bicuspid teeth separated by an interspace from the smaller inner teeth, theother subgenera having variously specialized crown forms to the teeth. Regan disregarded, orperhaps failed to appreciate the principal diagnostic feature which Pfeffer (1893) used to diagnoseCtenochromis, namely the very small scales on the thoracic region. Both Pfeffer and Regan over-looked other diagnostic features in Ctenochromis pectoralis (type species of the genus), none ofwhich is found in any of the 42 Victoria species placed in Regan's Ctenochromis subdivision ofthat flock (see p. 287 below). Recent research (summarized in Greenwood, 1974a) also indicatesthat these 42 species, and about an equal number described since Regan's 1922 revision, can besubdivided into several distinct groups. 268 P. H. GREENWOOD Similar arguments can be marshalled against Regan's (I922a : 253) statement that '. . . thespecies (of Haplochromis) not peculiar to the Great Lakes all belong to the subgenus Ctenochromis,Pfeffer . . .'; this aspect of the problem will be discussed later. Since Regan's time, no real attempts have been made to subdivide the genus (which nowcontains almost double the number of species known to Regan). Some species have been separatedoff as mono- or oligotypic genera, but these actions have in no way simplified the problem eithertaxonomically or phylogenetically, and the genus has still not been shown to be a monophyleticunit. Clearly, to test the phylogenetic integrity of such a large, ill-defined taxon will require muchdetailed and critical analysis. The present paper must be looked upon as a tentative first step inthat direction. I shall limit my detailed analysis to those Haplochromis species which I havestudied in some depth, viz. the species flock of Lake Victoria (which contains the type species,H. obliquidens) and those of Lakes Turkana, Albert, Edward and George, together with the fewHaplochromis occurring in Lake Tanganyika, and the purely fluviatile species from Africa andthe Middle East. Also included are the Haplochromis-\ike riverine genera Orthochromis Green-wood, Serranochromis Regan and Rheohaplochromis Thys van den Audenaerde, and the partlylacustrine Astatoreochromis Pellegrin. Unfortunately, I have been unable, through lack of first-hand knowledge, to include the Lake Malawi Haplochromis flock. However, I trust that theresults of my analysis of these other Haplochromis species will enable workers on the Malawifishes to review the species of that lake in a new light. My review of anatomical, osteological and morphological features, including details ofsecondary sexual markings and coloration, has yielded one particularly significant (but notsurprising) result; there is, apparently, not one deiived feature shared only by the 190 speciesexamined. The commonly occurring tooth form, an unequally bicuspid tooth, is found in several othergenera, as is the unicuspid and caniniform type. Even some of the specialized dental types seemto have evolved independently in other genera, these genera, and those in which bi- and unicuspidteeth also occur, each being recognizable on the basis of derived features not sharedby Haplochromis. The structure of the cranial apophysis for the upper pharyngeal bones (see Regan, 1920) isprobably a derived feature (see Greenwood, 1978), but again it is a feature widely distributedamongst several genera whose close affinity with Haplochromis cannot be established. At best thepharyngeal apophysis can be used as an indicator of relationship at a more distant level than the'generic' one (see Greenwood, 1978). No derived features of the anatomy or the squamation are universally shared amongst all thespecies although, as with various other characters, distinct groups can be defined withinHaplochromis on the basis of shared derived features. The anal fin markings found in adult male Haplochromis, the so-called anal ocelli or egg-dummies (see Wickler, 1962a & b\ Trewavas, 1973), have been considered a unique feature of thegenus. Trewavas (1973 : 34) expressed the generally held view on these markings when she wrote'. . . within their endless diversity the species of Haplochromis have almost universally in commona feature of the colour-pattern, the well-known ocellar spots on the anal fin of the male' (italicsmine). Certainly such ocellar markings are present in all the described species of Haplochromisfrom Lake Victoria, Edward, George and Kivu, and probably in those from Lake Turkana aswell. But, true ocelli (i.e. a central coloured spot with a clear surround) are not found in thespecies of Lake Albert, in the majority of species occurring in the rivers, nor even in many ofthe Lake Malawi species (see figs in Axelrod & Burgess, 1977). Coloured markings do occur onthe anal fins of these fishes (sometimes in both sexes), but are in the form of spots without aclear surround, often smaller than the true ocellar type, sometimes more numerous and coveringthe greater part of the fin, sometimes only as one or two spots, or, less commonly, similar innumber (3-5) and linear arrangements to the true ocellar type. Clearly, the presence of ocellar anal markings cannot be considered a character of Haplochromisas that genus is currently conceived, and the value of anal markings per se as an indicator ofphyletic relationship must be reassessed. A REVISION OF THE HAPLOCHROMIS GENERIC CONCEPT 269 Although a monophyletic origin for the 'genus' Haplochromis cannot be established, it ispossible to recognize several seemingly monophyletic lineages (reconstructed on the basis ofsynapomorphic characters) amongst the species of Lake Victoria (Greenwood, 19740 and un-published). None of the six major lineages recognized in that lake, however, could be interrelatedon a sister-group basis (although sister-groups could be recognized within five of the lineagesthemselves). In other words, the synapomorphic features of each lineage are superimposed on abasic, plesiomorphic 'bauplan' shared by all*. A similar picture emerges when the fluviatile species, and those from Lakes Albert, Turkanaand Tanganyika are examined closely. That is, one can postulate a number of lineages (somecontaining both fluviatile and lacustrine members), but none can be further interrelated on thebasis of synapomorphic features. With the possible exception of their occurrence in two species (one from Lake Victoria, theother from Lake George), none of the apomorph features used to delineate these lineages hasbeen observed amongst the 'Haplochromis' species of Lakes Victoria, Edward, George and Kivu. Although no apomorph character has been found to unite all the species of Lakes Victoria,Edward, George and Kivu, and thus suggest their common ancestry, species from the differentlakes can be grouped into common lineages each of presumed monophyletic origin. For thatreason the 'Haplochromis'' of Lakes Edward, Kivu and George will be treated together with thoseof Victoria in a forthcoming paper (except for those species which are now referred to the redefinedgenus Haplochromis, see p. 280). To summarize, the so-called Haplochromis species of Africa (excepting those of Lake Malawiwhich are not included in this review) can be split into a number of major lineages. Most of theselineages are characterized by derived features unique to its members. The different lineages cannot be interrelated on a sister-group basis for want of ascertainablesynapomorphic features which would permit the recognition of their sister-group status. I usethe qualification 'most of these' because one of the groups cannot be defined on the basis ofeven a single shared apomorph character. This is the group in which must be placed the widespreadH. bloyeti species complex of east Africa (see Greenwood, 1971, 19740) and, probably, certain ofthe generalized endemic species of Lake Victoria, Edward and Kivu ; it is recognized merely onthe overall similarity (and plesiomorphy) of its constituent species. Wherever breeding habits are known, members of the various lineages described in this paperare female mouth brooders, and all have a 'Haplochromis' -type cranial apophysis for the upperpharyngeal bones (Greenwood, 1978), features shared with the 'Haplochromis' and severalseemingly related species in Lake Malawi (Trewavas, 1935; Greenwood, 1978). Oral broodingand its associated spawning behaviour, as compared with substrate spawning and brood-care, isa derived condition; the 'Haplochromis'' -type apophysis would also seem to be a derived feature.One may therefore hypothesize a shared common ancestry, at some point, both for the lineagesdescribed below and for those which eventually will be recognized amongst the Lake Malawihaplochromine species (i.e. those with a 'Haplochromis'-type pharyngeal apophysis and, probablyspecies with a 'Tropheus'-type apophysis as well; see Greenwood, 1978). For the moment, however, and until it is possible to interrelate dichotomously the variouslineages on a sister-group basis, one is faced with a series of unresolved dichotomies (see, forexample, the problem discussed on p. 313). In classifying this assemblage I have followed theconvention suggested by Nelson (1972), namely that the taxa (i.e. the individual lineages) begiven equal rank. At this stage in our knowledge of supraspecific relationships amongst Africancichlids, generic rank would seem to be the most appropriate. Methods and materials Methods In essence I have attempted to break up the 'genus' Haplochromis into a number of monophyletic * It has been assumed (on the basis of overall morphological similarity between the least specialized members ofeach lineage) that the endemic Haplochromis species of Lake Victoria are of monophyletic origin (Greenwood,1974a). Since no apomorph feature unique to the Victoria species has yet been found, that hypothesis is withoutformal support. 270 P. H. GREENWOOD lineages, the members of each lineage being related by their relative recency of common ancestry.Recency of common ancestry, in turn, is recognized by members of a lineage possessing derived(apomorph) characters which are not shared with other species. Determining the primitive (plesiomorph) or derived status of characters in the Cichlidae is atpresent a very difficult task. No guidance is available from the entirely inadequate fossil record,and the family's nearest living relatives have yet to be recognized. Comparisons between differentcharacter states (outgroup comparison, see Hecht & Edwards, 1977) ideally should be carried outacross the whole family. As there are well over 600 nominal species in Africa and America, fewof which have been studied in the detail necessary for proper phyletic analysis, the level of out-group comparisons employed in this paper is, perforce, a low one. All comparisons have been restricted to African taxa, in particular to species and lineageswithin the group having a 'Haplochromis' -type of pharyngeal apophysis. This decision was madeon the assumption that all such taxa were derived from a common ancestor, albeit a distant one,and that the 'Haplochromis'-type apophysis, relative to the ' Ti lap la" -type, is itself a derivedcharacter. The most detailed comparisons, of course, have been those made between speciescomprising the lineages discussed in this paper. Outgroup comparisons have also been made with species having a 'Tilapia'-type apophysis, inparticular the lineages represented by the genera Sarotherodon and Tilapia. When comparisons were made with Haplochromis from Lake Victoria, the Victorian lineageswere those discussed in Greenwood (1974a). Since no such breakdown is available for the endemicHaplochromis of Lake Malawi or for the endemic genera with a 'Haplochromis'' -type apophysisin Lake Tanganyika, these various taxa were not involved in the analysis. The particular characters and character transformations studied are those which, after apreliminary survey of the taxa involved*, seemed to be most likely to yield information on theirderived or primitive states within the material available and within the limits of the tests whichcould be applied to the conclusions reached. As might be expected, the principal test was that of the distribution of a character state amongstthe species compared. The state having the widest occurrence is assumed to be the most primitiveone, that with the most circumscribed distribution the derived one (the so-called commonalityprinciple of Schaeffer, Hecht & Eldredge, 1972). The characters finally selected, and a few others that deserve comment, can now be discussed. (/') Squamation. All Haplochromis have the scales on the chest region (the area anterior to a linethrough the pelvic and pectoral fin insertions, and ventral to a horizontal line through the ventralpart of the pectoral fin insertion) smaller than those on the ventral and ventrolateral parts of thebody. The common condition is that in which the size change between the scales of the two regionsis a gradual one, see Fig. 1 ; even when, as in H. squamulatus of Lake Victoria, the chest scales arenoticeably small, the size change is still gradual (see fig. 17 in Greenwood, 1967). The less frequentcondition is that in which the size transition (usually along the line between pectoral and pelvicfin insertions, but sometimes a little further posteriorly) is abrupt ; since in these fishes the chestscales are generally small and numerous, the chest squamation is noticeably distinct from thatof the belly and ventral flank regions (Figs 2 & 3). A totally scaled chest, irrespective of squamation pattern, is the usual condition; circum-scribed, bilaterally symmetrical naked patches are uncommon and are confined to species showingan abrupt size transition in thoracic-abdominal scale sizes. A completely naked chest is the mostuncommon condition and would seem to be the end point in the apomorphic morphocline:abrupt size change -^ bilateral naked patches * completely naked chest. Although the ventral body scales extending posteriorly from the pelvic fin insertions to theanus are smaller than those on the lateral and ventrolateral aspects of the flanks, the size gradationbetween the two fields is generally gradual. However, in a few species the ventral (belly) scales aremuch reduced in size and thus are clearly demarcated from the flank scales above them. This * The Haplochromis species of Lakes Victoria, Albert, Turkana, Tanganyika, Edward, George and Kivu, of theAfrican rivers and those of Syria and Israel, and the species of Serranochromis, Rheohaplochromis, Orthochromis,Astatoreochromis, Macropleiirodus, Platytaeniodus and Hoplotilapia, a total of some 390 species. A REVISION OF THE HAPLOCHROMIS GENERIC CONCEPT 271 condition is correlated with an equally marked and abrupt size reduction in the scales on thechest, so that the tiny abdominal scales appear as a posterior and ventrolateral extension of thoseon the chest (Fig. 3). Such an arrangement is also considered to be a derived condition. Surprisingly, in a group of species where most morphological features appear as elements in acontinuum of differentiation, the various scale patterns discussed above are very trenchantlyseparated from one another. The few intermediate specimens I have observed are clearly individualrather than populational or specific variants. As with the chest, a completely scaled cheek is the common condition, the scales being arrangedin three or four horizontal rows. Reduced squamation is encountered infrequently, but rangesfrom a narrow naked band (one or two rows deep) along the ventral margin, to an almost com-pletely naked cheek with only the suborbital row, or part of that row, persisting. 10mmFig. 1 Thoracic-abdominal scale transition in Astatotilapia nubila; left lateral view. On the principle of commonality (Schaeffer et al, 1972), strongly ctenoid body scales should belooked upon as the primitive condition, and an increase in the area of the body covered bycycloid or reduced ctenoid scales should be considered the derived one*. Some uncertainty about this conclusion could be raised by the situation in Hemichromis, alsoa ' Haplochromis'' group species (see Regan, \922a). Here the scales are mostly cycloid with a fewweakly ctenoid ones confined to the anterior part of the body ; that is, a presumably derivedcondition. But Hemichromis species are substrate spawners and brood guarders, a presumedprimitive condition amongst African cichlids. Since certain other characters in Hemichromis areapparently derived ones (the unicuspid outer teeth, the number of inner tooth rows (one or none),and the form of the upper jaw), the cycloid scales may have evolved independently in the lineage.On the other hand, the presence of cycloid scales in 'Tilapia' group species (see footnote), someof which are also substrate spawners and all of which have an apparently plesiomorph type ofpharyngeal apophysis (see Greenwood, 1978), would appear to strengthen the argument forconsidering cycloid scales as primitive features. In the face of such contradictory observations itwould seem advisable not to use this type of scale ornamentation in phyletic analysis. All the Haplochromis and Haplochromis group species used in this review (see footnote p. 270)have less than the proximal two-thirds of the caudal fin covered by small scales; usually only the * Most taxa in the "Tilapid 1 group, as defined by apophyseal structure (see Greenwood, 1978), have cycloid scales,although some have a few weakly ctenoid scales on the anterior part of the body). 272 P. H. GREENWOOD 5mm Fig. 2 Thoracic-abdominal scale transition in Thoracochromis wingatii; left lateral view. 5mmFig. 3 Thoracic-abdominal scale transition in Orthochromis polyacanthus; left lateral view. proximal half is covered. In contrast, all the endemic lacustrine species from Lake Malawi havethe entire fin densely scaled (Trewavas, 1935). The partly scaled condition is assumed to be theplesiomorph one. (//') Dentition. Outer tooth row in both jaws. The most frequently occurring tooth form (Fig. 4)is that with an unequally bicuspid crown, moderately distinct neck and relatively stout bodyfirmly attached to the underlying bone. Neither cusp is strongly compressed, their tips are acuteor subacute and lie in or but slightly outside a vertical drawn through the corresponding outermargin of the tooth's body. Such teeth, apart from providing the definitive dental form in many A REVISION OF THE HAPLOCHROMIS GENERIC CONCEPT 273 species, also precede the definitive tooth type in species having unicuspid teeth in adult fishes,and also, in at least some species, precede the definitive types when these are much modifiedversions of the basic bicuspid (e.g. in H. obliquidens). Unfortunately, ontogenetic data on toothreplacement are not available for many species, so the generality of the latter observation isunknown. Because of its common occurrence and its primary position in the ontogenetic sequence oftooth replacement, the unequally bicuspid tooth is taken to be the plesiomorph dental type.Bicuspid teeth in which there is a differential growth of one cusp (usually the larger one) or equaldevelopment of both cusps are considered to be derived features, as are unicuspid teeth. As mentioned above, most taxa having a definitive outer row dentition composed of unicuspidteeth also have an ontogenetically earlier one of bicuspids (usually persisting until an individualfish is between 80 and 100 mm standard length). Any shift forward in the time or body size atwhich the definitive unicuspid teeth appear can therefore be interpreted as being a derivedcondition. 1mm Fig. 4 Outer row jaw teeth (premaxillary) of Astatotilapia flaviijosephi.A. Labial view. B. Lateral view (posterior aspect). From one to six (rarely as many as twelve) enlarged and unicuspid teeth occur posteriorly onthe premaxilla, even when the other teeth on that bone are bicuspids. The replacement of theseunicuspids by teeth similar to those on the rest of the premaxilla must be considered a derivedcondition. Inner row teeth. Here, on the grounds of common occurrence, small, tricuspid teeth mustrepresent the primitive condition. As with the outer teeth, there can be an ontogenetic successionof teeth types, tricuspids or a mixture of tri- and bicuspids preceding unicuspids. Occasionallysome or all inner rows are composed of highly modified bicuspid types resembling, albeit on asmaller scale, those of the outer row (e.g. Haplochromis obliquidens and Macropleurodus bicolor;see Greenwood, 1974a). The presence of inner teeth other than tricuspids is a derived condition. Since most commonlythere are from 2 to 3 rows of inner teeth, any increase or decrease in the number of rows mustalso indicate an apomorph condition. (Hi) The lower pharyngeal bone and its dentition. The most commonly encountered form of lowerpharyngeal bone has an approximately equilateral, triangular dentigerous surface, is not noticeablythickened or robust, and has its anterior blade-like portion neither noticeably elongate nor short(Fig. 5). The teeth are arranged anteroposteriorly in about 30 to 50 rows, with those in the two medianand in the posterior transverse row stouter than the others but, like them, retaining an unequallybicuspid crown in which the minor cusp is a near horizontal shoulder and the major one is weaklyfalciform and vertically aligned. Apomorphic derivations from this basic type include changes in overall outline shape of thedentigerous area (Fig. 14), elongation of the anterior blade, increase or decrease in the numberof tooth rows, an increase or, less commonly, a decrease in the number of rows of coarser teeth 274 P. H. GREENWOOD (Figs 20 & 8), and changes in crown morphology of the teeth (generally a process of molarizationassociated with a general coarsening of tooth form; see Fig. 18B). (iv) Neurocranial morphology. Modal neurocranial form (and thus the presumed plesiomorphcondition) is best appreciated from a drawing (Fig. 6). Salient features are the moderately high supraoccipital crest (c. three-quarters of the depth ofthe otic skull region measured from roof to ventral parasphenoidal face, but excluding thepharyngeal apophysis); the preorbital skull profile (from vomerine tip to the anterior point of thesupraoccipital crest) rising at an angle of cA5, its outline gently curved and its ethmovomerineregion sloping forwards and downwards at a slight angle; the preotic part of the skull (measuredfrom the vomerine tip to the anterior vertical wall of the prootic bone) comprising some 55-60 %of the total length of the neurocranium, and the otic region of the skull not inflated. The pharyngealapophysis is not enlarged, and the prootic does not contribute to the articular surface (Greenwood,1978). A B 3mm Fig. 5 Lower pharyngeal bone of Astatotilapia bloyeti. A. Occlusal view.B. Right lateral view (bone aligned vertically). Derivative conditions include elongation of the preotic part of the skull (to about 70% of theneurocranial length) correlated with a flattening of the preorbital skull profile (Fig. 13); narrowingof the otic region, and in some variants a relative lowering of the supraoccipital crest; the reten-tion of a basic skull form in the otic region but a marked increase in the slope of the ethmovomerineregion (in some species almost to the vertical) and a correlated increase in the slope and curvatureof the preorbital skull profile; the retention of basic otic and ethmovomerine regions but theelevation of the preorbital skull roof so that the neurocranium becomes higher and more angularin outline (see Greenwood, 1974a, for further analysis and figures). Departure from the plesiomorph condition for the pharyngeal apophysis is always associatedwith an hypertrophy of the upper and lower pharyngeal bones and their dentition (see Greenwood,19650, 19740, 1978). (v) Anal fin markings (egg-dummies) in male fishes. Reference has already been made (p. 268) tothe variety of these markings in Haplochromis. (See Wickler, 19620 & b, 1963 for a discussion oftheir importance in the breeding biology of these fishes). Regrettably there is little information about these markings in live fishes, and what has beenrecorded is often insufficiently detailed to be of value. For instance, it is important to know if the A REVISION OF THE HAPLOCHROMIS GENERIC CONCEPT 275 markings are merely coloured spots, whether each spot has a contrasting border, or whether it istruly an ocellus with a wide and translucent surround. The number and distribution of themarkings are also important data. My own observations on live fishes from different parts ofAfrica, and on preserved material as well, all suggest that the anal markings (or their absence)may be of considerable value in helping to define lineages. But, because of a paucity of informa-tion for many species considered below it has proved impossible to use the character fully inthis study. It seems reasonable to assume that the egg-dummy markings (using that term in its widestsense and not just for true ocelli) were derived from coloured streaks and spots like those thatare an almost universal feature on the dorsal fins of cichlids (see Wickler, 19620). The first stepsin the evolution of egg-dummies from a maculate colour pattern would involve a slight reductionin the number of spots and a consequent increase in the space between them, and the intensifica-tion or alteration of their colour so as to differentiate the anal spots from those in the dorsalfin. The end point in this process of differentiation seemingly would be reached with the develop-ment of ocellar spots. 5mmFig. 6 Neurocranium of Astatotilapia bloyeti; left lateral view. In species with true ocellar egg-dummies (e.g. the Haplochromis of Lake Victoria; seeGreenwood, 1974a, especially plate I) the number of spots is reduced to modes of 3 or 4, thecoloured centre of each spot is ovoid in outline, generally has a narrow black or dark border andis surrounded by a clear zone of fin membrane; other spots and markings on the fin are suppressed,although the greater part of the fin may have a coloured flush. The result is a most distinctivemark, with an illusion of three dimensionality, that is readily distinguished from any other finor body markings. There are, of course, other kinds of anal marking which, in their appearance, size and distri-bution on the fin, are intermediate between the supposed plesiomorph type (numerous, non-ocellate spots) and the presumed apomorph kind described in the last paragraph. Their possiblephylogenetic importance will become apparent when more information is available not only ontheir appearance in live animals, but also on their functional role in mate recognition, courtshipand spawning. For the moment one can assume that the ocellar spots represent the apomorph condition andthat the multiple spot type of anal marking is the plesiomorph one. Those Haplochromis-\ikespecies apparently without any spatially or chromatically differentiated anal markings (e.g.Orthochromis malagaraziensis; Greenwood, 1954) provide a particular problem because we knownothing of their reproductive behaviour. Thus the absence of 'egg-dummies' cannot necessarilybe construed as representing a plesiomorph condition in these species. 276 P. H. GREENWOOD (vi) Vertebral numbers. The modal range of total vertebral counts (excluding the fused Purostylar element) is 27-29 (comprising 12-14 abdominal and 15 or 16 caudal centra). On thegrounds of its being the modal number, it is taken to be the plesiomorph condition. Apomorphic deviations occur amongst the Haplochromis species of Lake Victoria where a fewspecies show a higher modal count (30-32); these are all long-bodied piscivorous predators andthe increase in the number of vertebrae occurs in the caudal section of the column. Parenthetically,it may be noted that Lake Malawi Haplochromis species with more than 32 vertebrae also showan increase in the number of caudal elements. The most marked increase in vertebral numbers (apart from that in some Malawi species) isfound in the genus Serranochromis. Here the modal counts are 33 and 34 (abdominal modes16-17, caudal modes also 16 and 17), with an increase in the number of abdominal rather thanthe caudal elements as was the situation in the Victoria and Malawi Haplochromis species. A similar increase in the number of abdominal vertebrae is also found in the seven Zambezispecies of so-called Haplochromis revised by Bell-Cross (1975). In these species there is, however,a reduction in the number of caudal vertebrae as compared both with Serranochromis and withthe plesiomorphic Haplochromis condition (14 and 15 in the Zambezi species, 16 and 17 in theothers). In consequence, the modal total count (29-32) for the Zambezi fishes overlaps that ofthe plesiomorph Haplochromis type. For want of falsifying evidence, the Serranochromis and 'Zambezi Haplochromis' conditionsare both considered to be apomorphic ones. In some Haplochromis-like genera, certain species have low counts for caudal vertebrae, butmodal ones for the abdominal elements (see p. 290); probably these taxa, in the phyletic contextof their particular lineages (and for this particular character), should be considered derived(i.e. autapomorphic). (v/7) Caudal fin skeleton. Vandewalle (1973) has provided a summary of the caudal fin skeletonin 108 cichlid species, mostly African. He shows that, overall, there is a remarkable constancy inthis feature but that in some species individual hypural elements may fuse (especially hypural 1with 2, and 3 with 4; the fifth hypural is always free except in one species (see p. 292) - Vandewallefinds no instance of fusion between all hypurals). My own observations generally confirm those of Vandewalle, but strongly indicate that, withone possibly exceptional lineage (see p. 297), hypural fusion is an individual and not a specificor lineage trait. It is thus of very restricted value as an indicator of phyletic affinities, as is theorganization of the whole caudal fin skeleton amongst the taxa examined. (v//7) Number of dorsal and anal fin rays. Amongst the Haplochromis species and related taxareviewed (see footnote p. 270) the modal numbers of dorsal fin rays are 15 and 16, and of branchedrays 9 and 10. Except for obvious individual variants, and two species of Astatoreochromis, allthese taxa have 3 spinous rays in the anal fin and, modally, 8 or 9 branched rays. If, on the principle of commonality, these numbers are taken to be the basic (i.e. plesiomorph)counts, then modal ray counts for either fin that are higher or lower should be considered derivedfeatures. (/*) Gill rakers. There is a fairly narrow range of both gill raker numbers and shapes (counts andobservations restricted to the outer row of gill rakers on the lower part of the first gill arch). Inmost species the rakers are relatively robust, simple structures (with sometimes the upper 2 or 3of the series flattened and bi-, tri- or even polyfid), of moderate length and numbering from 7 to12 (modal counts 8 and 9). Materials All the BMNH material (spirit specimens, alizarin preparations, dry skeletons and radiographs)of all the taxa named in this paper has been examined, as have the Museum's collections ofHaplochromis species from Lakes Victoria, Edward, George and Kivu, and selected specimens fromthe collection of Lake Malawi Haplochromis species and related genera. A REVISION OF THE HAPLOCHROMIS GENERIC CONCEPT 277 In addition, the following specimens, borrowed from other institutions, have also been studied(and radiographed). Haplochromis albolabris (Holotype) Haplochromis angusticeps Haplochromis bakongo (Paratypes) Haplochromis buysi (Holotype) Haplochromis darlingi Haplochromis fasciatus Haplochromis giardi (Holotype) Haplochromis luluae (Paratypes) Haplochromis oligacanthus Haplochromis polli (Paratypes) Haplochromis stappersi Haplochromis thysi (Holotype) Haplochromis toddi (Holotype) Haplochromis torrenticola Chetia brevis (Holotype) Chetia brevis (Paratypes) Chetia brevis Chetia flaviventris Ctenochromis pectoralis (Lectotype) Ctenochromis pectoralis (Paratypes) H1784 ANSP 54369-76RMAC 16945-947WHP1219AM/P2461RMAC 48407-4 15MHN A2754ANSP 5 1759-62RMAC 167930-931RMAC 99403-404RMAC uncataloguedRMAC 163991RMAC 1346IRSN 1809-1960AM/P951AM/P952AM/P1425-6AM/P1298ZMH402ZMH403 AM/P, Albany Museum; ANSP, Academy of Natural Sciences of Philadelphia; IRSN, InstitutRoyal des Sciences Naturelles de Belgique; H, Zoologisches Museum, Hamburg; MNH, MuseumNational d'Histoire Naturelle, Paris; RMAC, Musee Royal de 1'Afrique Centrale, Tervuren;WH, Windhoek Museum; ZMH, Zoologisches Museum, Berlin. Classification Applying the methodology and reasoning discussed above and in the Introduction, nine lineages,here given generic rank, may be recognized amongst the taxa studied. With the exception only ofChetia, each of these genera now contains species that were previously placed in Haplochromis. Unless indicated otherwise, all the genera have a cranial apophysis for the upper pharyngealbones formed from the parasphenoid and basioccipital (see 'Haplochromis'' -type apophysis inGreenwood, 1978) and a caudal fin scaled on its proximal half or less. All vertebral counts quoted exclude the fused PU! and Ui centra, and may thus be lower thanthose used by some other authors; abdominal vertebrae are identified as those bearing pleuralribs (including, of course, the first two vertebrae that have no ribs), and the caudal centra asthose without ribs but, except occasionally the first (anterior) centrum, with a haemal arch. Since the genus Haplochromis is now restricted to five species (see p. 280), difficulties arisewhen reference is made either to species formerly included in that genus, but which have not yetbeen assigned to other genera, or to the former concept of the genus Haplochromis. To avoidconfusion, I have adopted the convention proposed and used by Patterson & Rosen (1977 : 163)for dealing with such situations. Namely, to prefix the species name with its former generic namecited between quotation marks, i.e. 'Haplochromis' nigricans or '//' nigricans. When reference ismade to the former concept of the genus the generic name alone, but in quotation marks, is used. The Lake Victoria 'Haplochromis' species will be reviewed in a paper now in preparation;until its publication these species can be referred to by using the old generic name in quotes. Asa temporary expedient for general use until such times as the Lake Malawi 'Haplochromis' arerevised, a purely formal generic name for these species is proposed on p. 317. Species mentioned in this paper are listed in the index on p. 321 under their former genericnames (usually Haplochromis}, with a reference first to the page on which they are listed in theirnew generic grouping, and secondly to the page on which that genus is described. 278 P. H. GREENWOOD In the generic descriptions, presumed apomorph (i.e. derived) character states are italicized. The generic revision which follows is arranged in two parts. After redefining the genus Haplo-chromis Hilgendorf, 1888, the first section will deal with "Haplochromis" species from LakesTurkana, Albert, Tanganyika and Mweru, and with those from the Nile and Zaire river drainagesystems, and the rivers of Kenya, Uganda and Tanzania. The genera Onhochromis Greenwood, 1954, and Astatoreochromis Pellegrin, 1903, will also beconsidered in this section of the paper. The second section (p. 299) will be concerned with the genera Serranochromis Regan 1920 andChetia Trewavas, 1961, together with those ' Haplochromis" species from the Zambesi, Limpopoand Angola river systems, which were thought to be related to Serranochromis and Chetia (seeTrewavas, 1964). Section I HAPLOCHROM1S Hilgendorf, 1888 TYPE SPECIES: Chromis (Haplochromis) obliquidens Hilgendorf, 1888 (type specimens in theHumboldt Museum, Berlin). Description Body relatively deep (depth 35-40% of standard length). Squamation. Scales on the body below the lateral line, and behind a line through the pectoraland pelvic fin insertions, are ctenoid; those above the upper lateral line and on the head andchest are cycloid. The small scales on the chest grade imperceptibly in size with those on the ventrolateral andventral aspects of the flanks (p. 270). Cheek and chest fully scaled. Lateral line with 29-34 scales (modal range 30-32) ; all but the last 3 or 4 scales of the upperlateral line are separated from the dorsal fin base by at least two scales of approximately equalsize. Neurocranium. The skull is of a generalized type (see p. 274; Fig. 6, and Greenwood, 19740),its ethmovomerine region having only a slight downward slope, the dorsal surface of the vomersloping in the same plane and at the same angle as the anterior part of the skull roof; the preoticpart of the skull comprises some 55-60% of the total neurocranial length. Vertebral numbers: 28-30 (modes 28 and 29), comprising 12-14 (mode 13) abdominal and15 or 16 caudal elements. Dentition. The outer teeth in both jaws are weakly bicuspid or unicuspid, the crown of the toothcompressed and noticeably expanded relative to its slender, cylindrical neck and body (Fig. 7). Themajor cusp in bicuspid teeth is very much larger than the minor one, which is often little more thana slight, obliquely truncated basal point on the posterior margin of the anteriorly protracted andslightly incurved (i.e. buccally directed) major cusp. The compressed, anteriorly protracted anddorsoventrally expanded major cusp gives to the tooth, be it bi- or unicuspid, the appearance ofhaving an obliquely truncated crown. The tip of this cusp lies outside the vertical formed by theanterior margin of the tooth's body. All outer teeth, save in some species for a few posterior teeth on the premaxilla, are moveablyattached to the underlying bone. In some species the posterior one to six teeth on the premaxilla are unicuspid or acutelybicuspid, and are stouter and larger than the others in that series; these posterior teeth in otherspecies of the genus closely resemble, in size and cusp morphology, their anterior congeners. Teeth forming the inner rows in both jaws mostly are small and tricuspid, but in some speciesthe anterior and anterolateral teeth in the outermost row may be identical with those of the outerrow. The inner teeth are arranged so as to form a tooth band that is wide anteriorly and antero-laterally, but narrow posterolaterally. This is effected by an increase in the tooth rows from theprimitive state of two or three to the derived condition of from 4 to 6. Lower jaw is relatively slender in lateral aspect and not noticeably deepened posteriorly; thelength of its dentigerous surface is equal or about equal to the greatest depth of the dentary (as A REVISION OF THE HAPLOCHROMIS GENERIC CONCEPT 279 B D 1mm Fig. 7 Outer row jaw teeth (premaxillary) in various Haplochromis species; a. labial view, b. lateral (posterior) view. A. H. annectidens. B. H. obliquidens. C. H. Umax. D. H. astatodon. measured vertically from the posterior tip of its ascending coronoid process to the ventral marginof the bone). Lower pharyngeal bone and dentition. The dentigerous surface of the bone is triangular andapproximately equilateral in outline (Fig. 8). The teeth, except for those forming the posteriortransverse row, are slender with the greater part of the cusp protracted and curved posteriorlyso that most of the occlusal surface lies nearly parallel with the surface of the pharyngeal bone.(The absence of a distinctly coarser median series of teeth probably is a derived feature; see p. 273.) Dorsal fin with 14-16 (modes 15 and 16) spinous and 8-10 (mode 9) branched rays. Anal fin with 3 spinous and 7-10 (mode 9) rays. Caudal fin skeleton without fusion between any of the hypural elements; none of the speciesreviewed here was examined by Vandewalle (1973). Caudal fin truncate or subtruncate, the posterior margin straight or weakly emarginate. Pelvic fins with the first branched ray the longest. Anal fin markings. True ocellar egg dummies (see p. 274), usually 3 or 4 in a single row, arepresent in adult males. Some females may have a similar number of small, non-ocellate spotspresent in the same position on the fin. 280 P. H. GREENWOOD Gill rakers are moderately slender, with 8-10 (mode 9), rarely 7, present on the outer row onthe lower part of the first gill arch. Contained species Haplochromis obliquidens Hilgendorf, 1888 (Type species). Lake Victoria (see Greenwood, 19560). Haplochromis lividus Greenwood, 1956. Lake Victoria (see Greenwood, 1956a). Haplochromis annectidens Trewavas, 1933. Lake Nabugabo (see Greenwood, 19656). Haplochromis Umax Trewavas, 1933. Lakes Edward and George (see Greenwood, 1973). Haplochromis astatodon (part) Regan, 1921. Lake Kivu. When reviewing this species 1 foundthat two distinct types of outer jaw dentition are represented amongst the 1 3 specimens and oneskeleton on which Regan (192 la) based his original description of the species. That there are twotypes of teeth represented in this sample is implicit in Regan's comment that the dental morpho-logy of H. astatodon is annectant between that of H. obliquidens and the simple bicuspid toothfound in many of Lake Victoria ' Haplochromis' species. B Fig. 8 2mm Lower pharyngeal bone of H. lividus. A. Occlusal view.B. Right lateral view (bone aligned vertically). Six of the syntypical specimens (BMNH reg. nos 1906.9.6 : 124-129) have outer teeth re-markably like those of H. obliquidens. That is, the crown is obliquely truncate and greatly pro-duced (Fig. 7D), the neck and body fine, and the teeth are moveably implanted in the gum tissue.However, in these specimens a minute second cusp is present on many of the anterior and antero-lateral teeth, a condition seen only amongst some of the posterior teeth in H. obliquidens. Theseparticular specimens of H. astatodon also resemble H. obliquidens in having many teeth in theoutermost of the multiseriate inner rows enlarged and often obliquely cuspidate; the inner teeth,like those in H. obliquidens, being small and tricuspid. The pharyngeal dentition in those specimens is also like that in H. obliquidens, but the twospecies differ in certain morphometric features and thus would seem to represent distinct species. The eight other syntypical specimens of H. astatodon (BMNH reg. nos 1906.9.6:130-132;1977.5.2:1-4 (the material was originally under-registered, hence the lot registered in 1977)), anda skeleton (BMNH reg. no. 1906.9.6:133) have distinctly bicuspid teeth in which the major cusp,although somewhat obliquely truncate, is neither protracted nor expanded, nor is it markedlycompressed; the minor cusp is not so greatly reduced as it is in the other syntypical specimensof H. astatodon, or in H. Umax, H. annectidens and H. obliquidens. A REVISION OF THE HAPLOCHROMIS GENERIC CONCEPT 281 The tooth form and dental arrangement in these aberrant syntypes does, however, approachclosely that found in ' Haplochromis' nuchisquamulatus of Lake Victoria and '//'. aeneocolor ofLake George (see Greenwood, \956a and 1973 for the species respectively). Because of this marked difference in dental morphology I am restricting the name 'astatodon'to the six syntypes (BMNH reg. nos 1906.9.6:124-129) with H. obliquidens-Yike teeth, and haveselected specimen 1906.9.6:125 as the lectotype. The eight specimens with ' nuchisquamulatus' '-liketeeth will be dealt with in a subsequent paper. Diagnosis and discussion The lineage here recognized as the genus Haplochromis is characterized by having obliquelytruncate and protracted crowns to the outer jaw teeth, an increase in the number of rows of innerteeth in both jaws (some of these teeth also having obliquely truncate crowns), and all jaw teethmoveably articulated with the underlying bone. The species are also characterized by their finelower pharyngeal teeth, and the presence of truly ocellar egg-dummies on the anal fin of adultmales. In their gross morphology, and in most aspects of their osteology and anatomy (thegreatly elongate intestine excepted), the species retain a generally unspecialized level oforganization. Dental features similar to those of Haplochromis do occur in other African Cichlidae, forexample Cyathochromis obliquidens Trewavas (1935) of Lake Malawi, but are associated withcharacters which indicate that these other taxa do not share a recent common ancestry withHaplochromis. Since all the taxa are grazers on epilithic or epiphytic algae their dental similaritiesmust be considered the results of convergent evolutionary trends. Within the genus Haplochromis, H. obliquidens and H. astatodon have what appears to be themost specialized (i.e. derived) form of teeth, and H. Umax the least specialized teeth (see Fig. 7C).The common ancestor could well have been a species with a 'limax'-like dentition. In a preliminary phyletic analysis of the Lake Victoria 'Haplochromis' species flock (Greenwood,1974a), '//'. nigricans was considered to be the sister species of H. lividus and H. obliquidens, and'H '. nuchisquamulatus the sister species of the other three species combined. My recent investi-gations now suggest, however, that '//.' nigricans (together with species from Lakes Edward,George and Kivu) form a distinct monophyletic lineage which cannot be related to Haplochromis(as here defined) on the basis of shared derived characters. Neither, on those grounds, can'//.' nuchisquamulatus be considered the sister group of Haplochromis, But, it cannot be deniedthat 'H.' nuchisquamulatus (and at least two other species, including the atypical H. astatodonnoted above) do have a tooth morphology approaching that of Haplochromis (in particularH. Umax). Tooth form in these species is what might be expected as an early stage of differentia-tion from the primitive bicuspid type in a morphocline leading to the 'obliquidens' type. Moreresearch is needed before any possible relationship between the five Haplochromis species andthe '//.' nuchisquamulatus complex can be clarified. ASTATOTILAPIA Pellegrin, 1903 TYPE SPECIES: Labrus desfontainii Lacepede, 1803 (type specimens, once in the Paris Museum butnow apparently lost). Description Body relatively deep (35-40% of standard length). Squamation. Over most of the body the scales are ctenoid, the ctenii generally strong andextending around the greater part of the scale's free margin ; scales above the upper lateral linemay be less strongly ctenoid than those below it, and in three species are partly or entirely cycloid.Scales on the nape and cheek are cycloid, as may be those on the chest, which is always com-pletely scaled. The chest scales show a gradual size transition with those on the ventral and ventrolateralaspects of the flanks (see Fig. 1); in some species the chest scales are not noticeably small, but inA. flaviijosephi, A. dolorosa and A. desfontainesi these scales are distinctly smaller (and inA. calliptera somewhat smaller) than are the chest scales in other species of the genus. 282 P. H. GREENWOOD The cheek is fully scaled, usually with 3 (less commonly 2 or 4) horizontal scale rows. The lateral line has from 28 to 30 scales (31-33 in A. desfontainesi), all but the last 1 to 4 scalesof the upper lateral line separated from the dorsal fin base by two or more scales of approxi-mately equal size. Astatotilapia swynnertoni is exceptional in having the last 6-8 scales of theupper lateral line separated by less than two scales of equal size. Neurocranium. The skull is of the generalized haplochromine type (see Greenwood, 1974a:58-59, and p. 274 above). The preotic portion of the skull is not protracted (comprising some55-60% of the neurocranial length), and the ethmovomerine region is short, sloping upwards at aslight angle. The dorsal skull roof may be straight or very slightly convex anterodorsal to theorbit. The supraoccipital crest is not reduced in length; its anterior border continues the lineformed by the dorsal surface of the ethmovomerine region and the orbital part of the skull roof. The ventral apophysis for the upper pharyngeal bones (see p. 274) is slightly enlarged in onespecies (A.flaviijosephi). The otic region of the skull is relatively deep, and is not inflated. Vertebral numbers: 27-30, rarely 26 (modes 28 and 29), comprising 12-14 (mode 13) abdominaland 14-16 (mode 15) caudal elements. The apophysis for the retractor dor sails pharyngeal musclesis small, and situated on the third vertebra. Dentition. In fishes less than 70 mm standard length unequally bicuspid teeth (Fig. 4) pre-dominate in the outer row of both jaws. The crown in these teeth is not noticeably compressed,neither is it clearly demarcated from the neck of the tooth (cf. Haplochromis, p. 278). Except intwo species, the cusps are acutely pointed and both lie within the verticals formed by the anteriorand posterior margins of the tooth's body; in A. calliptera and A. swynnertoni, however, at leastthe major cusp is somewhat obliquely truncate. Unlike Haplochromis, the outer teeth in Astato-tilapia are firmly attached to the bone. Even in specimens less than 70 mm SL some weakly bicuspid teeth and some unicuspids arefound in both jaws. In larger specimens the unicuspid type predominates. The proportion ofuni- to bicuspid teeth increases with the size of the individual; A. dolorosa, known only from theholotype, a fish 95 mm SL, has only unicuspid teeth. All species, and specimens of all sizes, have the posterior 3-12 teeth in the premaxilla enlargedand unicuspid. Teeth forming the inner rows are generally tricuspid and small; some weakly bicuspid or evenunicuspid teeth may occur in these rows, particularly in larger fishes. There are 1-3 (usually 2)rows of teeth anteriorly and anterolaterally in both jaws, a single row posteriorly and postero-laterally. Lower jaw is not foreshortened, nor is it noticeably deepened posteriorly. Lower pharyngeal bone and dentition. The dentigerous surface is apparently equilateral in allspecies. Except in A.flaviijosephi, all the teeth are compressed, slender and cuspidate, with onlythose teeth in the two median and the posterior transverse row somewhat coarser than the others.Cusp form is essentially similar to that in Haplochromis but the crown is not so markedly pro-duced as in that genus (cf. p. 279 above). In A.flaviijosephi, the teeth forming the median rowsare enlarged, with molariform or submolariform crowns; some teeth in the lateral rows also aresomewhat enlarged and have submolariform crowns. The lower pharyngeal bone, as comparedwith that in the other species, is stouter. Dorsal fin with 14-16 (mode 15), rarely 13, spinous rays and 8-11 (modes 9 and 10) branchedrays. Anal fin with 3 spinous and 7-10 (modes 8 and 9) branched rays; specimens of A. desfontainesiwith 4 spines have been recorded. Caudal 'fin skeleton. Astatotilapia burtoni (1 specimens radiographed) and A. nubila (9 specimens)show no hypural fusion, but the other 7 species all yielded certain individuals with some degreeof fusion in either the upper or the lower set of hypurals, or far less frequently, in both sets.It must be stressed, however, that these observations were made principally from radiographs andthat these can be difficult to interpret with accuracy if the hypurals are closely apposed to oneanother. Vandewalle (1973) reports no fusion in the two specimens of A. burtoni he examined.(It is not possible to tell from his paper whether these were radiographed or dissected specimens.) Caudal fin strongly subtruncate to rounded. A REVISION OF THE HAPLOCHROMIS GENERIC CONCEPT 283 Pelvic fin with the first branched ray longest. Anal fin markings in male fishes. True ocellar markings are present, usually 2-4 in number(but as many as 9 in large specimens of some species) arranged in one or less commonly in tworows, the number of rows positively correlated with the number of ocelli and the size of thespecimen. The row or rows of ocelli run along a line situated approximately midway betweenthe base and the distal margin of the fin. This linear arrangement (and that in Haplochromis}contrasts strongly with the near random arrangement of the anal spots in Serranochromis andChetia (see pp. 302 and 308 respectively). No information is available on the occurrence of anal spots (not ocelli, see p. 275) in the femalesof Astatotilapia species, except that 3 or 4 linearly arranged spots do occur in A. nubila fromLakes Victoria and George. Trewavas (1973), however, records seeing ripe female A. nubila andA. bloyeti with male-type ocelli on the anal fin, a phenomenon I never encountered when workingwith these species in the field. Where breeding habits are known, Astatotilapia species are female mouthbrooders. Indeed,A. burtoni is the species on which Wickler (19626) developed his dummy-egg theory to explainthe function of anal ocelli in spawning. Gill rakers of various shapes, from short and stout to moderately long and slender; 8 or 9, lesscommonly 7, in the outer row on the lower part of the first gill arch. Contained species Astatotilapia desfontainesi (Lacep.) 1803 (Type species)*; as restricted by Regan (19220) to specimens from Tunisia and Algeria. Astatotilapia flaviijosephi (Lortet), 1883. Israel and Syria. See Trewavas (1942) and Werner(1976) for redescription and biology. Astatotilapia bloyeti (Sauv.), 1883. The type specimens are from Kandoa (Great Ruaha system),Tanzania. Regan (\922a) included three other species in the synonymy of A. bloyeti, viz.Ctenochromis strigigena Pfeffer, 1 893, Tilapia sparsidens Hilgendorf, 1903 and Paratilapia kilossanaSteindachner, 1916. For the purposes of this revision I have accepted Regan's synonymy, butmuch more research is needed into the alpha level taxonomy of fluviatile haplochromine cichlidsin eastern and southern Africa before the species can be defined adequately. 1 have examinedmaterial from many localities in Kenya, Uganda and Tanzania, and also from Lake Chad andthe Upper Niger. This material would seem to represent a taxon closely similar, if not identical,to A. bloyeti, at least on anatomical and morphometric characters. However, judging from colournotes made on certain specimens from Tanzania there are strong indications that at least somepopulations are distinguishable on the basis of male coloration. An apparently undescribed species recently distributed by the aquarium trade under the name'Nigerian mouthbrooder' or 'Nigerian H. burtoni' probably should be included in the A. bloyeticomplex, as should an undescribed species from the Malagarasi river (personal observations). Until the necessary revision of these 'species' and populations has been carried out, the differenttaxa involved can be referred to as the 'A. bloyeti complex' (see Greenwood, 1971). Its distributionincludes rivers, streams and certain lakes in Kenya, Uganda, Tanzania, Nigeria and, probablythe Nile. Astatotilapia nubila (Blgr.), 1906. Lakes Victoria, Kioga, Edward, George, Nabugabo, Kachira,Nakavali and Kijanebalola, and river systems in Uganda which are connected with these lakes(see Trewavas, 1933; Greenwood, 19656 and 1973). The species has been widely distributed inUganda (and possibly Kenya and Tanzania as well) as a result of fishfarming and dam stockingactivities; its natural distribution is that listed in the first sentence. Astatotilapia dolorosa (Trewavas), 1933. Known only from the holotype, a specimen collectedfrom the Chambura river which flows into the Kazinga channel connecting Lakes Edward andGeorge. * The emended spelling of the trivial name, \lesjontainesi\ was first used by Boulenger (1899). Since Lacepedeintended that the species be named for M. Desfontaines, Boulenger's emendation, although not explained, wouldseem to be justified. 284 P. H. GREENWOOD Astatotilapia burtoni (Gunther), 1893. Lake Tanganyika and rivers associated with that lake(see Poll, 1956). The specimens recorded from Lake Kivu by Boulenger (1915) were misidentifi-cations (see Regan, 192 la). Astatotilapia stappersi (Poll), 1943. Rivers associated with Lake Tanganyika, see Poll (1956). Astatotilapia swynnertoni (Blgr.) 1907. Lower Buzi river, Mozambique. Astatotilapia calliptera (Gunther), 1893. Lakes Malawi and Chilwa; '. . . coastal rivers as faras the Save river, Mocambique' (Bell-Cross, 1976); Busi and lower Sabi-Lundi systems; LowerZambezi and Pungwe systems. Jubb (1967a) treats A. swynnertoni as a synonym of this species, but gives no reason for sodoing. Judging from the material I have examined, I would consider the two species to be distinct. Incertae sedis: Chetia brevis Jubb, 1968. The presence of 3 or 4 true ocellar markings on the analfin would seem to exclude this species from the genus Chetia (see p. 307 below, and p. 274 above),as would the predominance of ctenoid over cycloid scales on the body, and the retention ofbicuspid teeth as the predominant tooth form in specimens as large as 90 mm standard length(see p. 273). The inclusion of Chetia brevis in Astatotilapia is, however, very tentative and may well bealtered when the phylogeny and systematics of the 'Angolan Haplochromis' species are revised(see p. 312). Diagnosis and discussion The genus Astatotilapia is distinguished from the other fluviatile ' Haplochromis' group species bythe following combination of characters : male anal fin markings are true ocelli, large and usuallynumbering from 3 to 6, and are arranged in a single or, less frequently, a double row (the numberof ocelli and hence the number of rows correlated positively with the size of the fish); scales onthe chest region not sharply size-demarcated from those on the ventrolateral and ventral aspectsof the body; chest and cheek fully scaled; most body scales are ctenoid, the ctenii on each scalenot restricted to a narrow median arc on the scale's free margin but distributed along almost theentire free margin ; most teeth in the outer row of both jaws are bicuspid, the cusps of unequalsize, but the minor one never minute. The major cusp is acute or, rarely, somewhat obliquelytruncate but not protracted (cf. Figs 4 and 7). A few stout unicuspid teeth occur posteriorly inthe premaxilla of fishes at all sizes, and some may also be present anteriorly, in both jaws, offishes > 80 mm SL ; the inner teeth usually are tricuspid (occasionally some are weakly bicuspidor unicuspid) and are arranged in two rows anteriorly and anterolaterally; 27-30 (rarely 26)vertebrae, of which 12-14 (mode 13) are abdominal, and 14-16 (mode 15) are caudal elements;pelvic fin with the first branched ray the longest. Apart from the ocellar anal fin markings, none of these characters can be considered derived,and the anal ocelli are an apomorphic feature shared with Haplochromis and most, if not all' Haplochromis'' species from Lakes Victoria, Edward, George and Kivu, and some species fromLake Malawi as well. Thus, the possibility cannot be overruled that Astatotilapia is a non-monophyletic assemblage. The absence of other synapomorphic features shared with the genera described in this paperat least indicates that no members of Astatotilapia are closely related to any one of those lineages(as was implied when, hitherto, most were placed in the genus Haplochromis). The relationship of Astatotilapia to Haplochromis as now redefined is obscure. Both lineagesshare the apomorphic feature of anal ocelli, suggesting that both share a more recent commonancestry than either lineage does with any taxa not having this feature. Uncertainty also existsabout the relationship between Astatotilapia and the anal ocelli-bearing lineages of Lakes Victoria,Edward, George and Kivu, and for that matter some of the anatomically generalized 'Haplo-chromis' species of Lake Malawi. Any member of the Astatotilapia line with acutely bicuspid teeth (except, because of its speciali-zed pharyngeal mill, A. flaviijosephi) could, on purely morphological grounds, be taken torepresent the ancestral species for many lineages within the Victoria-Edward-Kivu species flock(see Greenwood, 1974a). It is, indeed, likely that a number of generalized but endemic speciesfrom that flock will have to be included in Astatotilapia, as may some from Lake Malawi. A REVISION OF THE HAPLOCHROMIS GENERIC CONCEPT 285 Relationships within the Astatotilapia lineage cannot be indicated at present, partly because nointragroup synapomorphies are apparent and partly because the species are as yet poorly definedand understood (see p. 283). Astatotilapia, like Thoracochromis (see p. 290) has a wide geographical distribution (one, indeedthat extends beyond Africa into the Middle East). Both genera occur in north Africa, althoughAstatotilapia does not apparently occur in the Nile drainage (except in Lakes Victoria and Kioga) ;Thoracochromis, on the other hand, is widely distributed in the Nile system but is poorly represen-ted, if at all, in Lake Victoria, and does not extend so far into southern Africa as does Astatotilapia. In general, it could be said that Astatotilapia is a lineage of eastern and southern Africa, withoutliers in the northeast (A.flaviijosephi) and northwest (Algeria and Tunisia), and Thoracochromisa lineage of north, central and western Africa. Since the phyletic integrity of both lineages isuncertain (see above, and p. 294), and because large parts of the Zaire system are poorly known,this difference may be more artefactual than real. ASTATOREOCHROMIS Pellegrin, 1903 TYPE SPECIES: Astatoreochromis alluaudi Pellegrin, 1903 (type specimens in the Paris Musuem).For synonymy see Greenwood (19590) and discussion below. Discussion Pellegrin (1903) distinguished Astatoreochromis (then monotypic) from similar ' Haplochromis' -group species and genera principally on its having 5 or 6 anal and 18 or 19 dorsal fin spines. Thetype species is from Lake Victoria, but later, specimens were collected from Lakes Edward andGeorge, the Victoria Nile and Lakes Kioga, Nakavali and Kachira (see Greenwood, 19590). Redescriptions based on this enhanced material added to the number of diagnostic features,at least with respect to the ' Haplochromis' species of Lakes Edward and Victoria (Greenwood,19590). Amongst those features are the rounded caudal fin, the high number and multiserialarrangement (3 or 4 rows) of the anal ocelli in male fishes, the unusual coloration (golden over-lain with olivaceous green, the median fins olive-yellow, flushed with maroon and margined withblack), and the lack of sexual dimorphism in basic body and fin colours. This material also ex-tended the known range of dorsal fin spine numbers (16-20) as well as those of the anal fin (4-6). The species Astatoreochromis alluaudi is further characterized by its strongly hypertrophiedcrushing pharyngeal dentition and bones (with a correlated hypertrophy of the cranial apophysisfor the upper pharyngeal bones; see Greenwood, 19590 and 19650). A similar degree of pharyn-geal hypertrophy does, of course, occur in at least five other species from Lakes Victoria, Edwardand George (Greenwood, 1960 : 270-279; 1973 : 172-177 ; Greenwood & Barel, 1978 : 164-179),but these species differ from A. alluaudi in several features, all of which suggest that A. alluaudirepresents a distinct phyletic lineage. The principal diagnostic characters for Astatoreochromis are not easily assessed on a basis oftheir apo- or plesiomorphy. The enlarged pharyngeal mill clearly is a derived feature, but is onethat has evolved independently in at least two ' Haplochromis' lineages (see Greenwood, 19740,and p. 279 above) ; it is thus of little value in assessing relationships at the level with which weare here concerned. As yet too little is known about the evolution and phyletic distribution of anal ocelli (and otheranal fin markings) to say whether the increased number and multiserial arrangement in Astatoreo-chromis is a derived feature. The basis for comparison here is with the fewer ocelli and their uni-or biserial arrangement in Haplochromis, Astatotilapia and the Lake Victoria ' 'Haplochromis'species. The absence of sexually dimorphic coloration in Astatoreochromis is a most unusual featureamongst 'Haplochromis' -like taxa, but would seem, a priori, to be a primitive rather than a derivedfeature (although its correlation with the increased number of anal ocelli and thus, possibly itsdegree of relative importance in breeding behaviour, cannot be interpreted without appropriateethological studies). Only the increased number of anal and dorsal fin spines (but, it should be noted, not the totalnumber of rays in these fins) would seem to be derived features. 286 P. H. GREENWOOD In the absence of other and synapomorphic characters, however, it is impossible to use finspines numbers to suggest any possible close phyletic affinities for Astatoreochromis. For example,the squamation pattern in the genus is of the supposedly plesiomorph type, and this would seemto rule out any possible relationship with the Orthochromis lineage (see p. 295) in which there isalso a marked trend towards increased numbers of dorsal and anal fin spines. Orthochromis, itmay be added, does not have anal ocelli or, apparently, any other anal fin markings in the males(the breeding habits of no Orthochromis species are recorded). That Astatoreochromis may be related (possibly as the derived sister-group) to some of the'Haplochromis' species with enlarged pharyngeal mills, cannot be completely discounted; but,equally there is little unequivocal evidence to support such an hypothesis (see above). For the moment, then, Astatoreochromis is maintained as a distinct lineage because of itsvarious distinctive features, taken in combination, and because its sister-group relationship toany other lineage cannot be hypothesised on the basis of uniquely shared derived characters. Recently, Poll (1974) added a second species (Haplochromis straeleni Poll, 1944, from theLukuga and Ruzizi rivers, Zaire) to the genus Astatoreochromis. This step was taken because somespecimens of straeleni have 4 anal spines (i.e. 2 of the 7 specimens known), because of closesimilarities in overall coloration and in the pattern and number of anal ocelli, and becausestraeleni has a relatively enlarged lower pharyngeal bone with some molariform teeth (see fig. 1 ,Poll, 1974). The species also has, as compared with Astatotilapia and the Lake Victoria 'Haplo-chromis'' species, more dorsal fin spines (17 or 18) but the same number of branched rays in thatfin (8 or 9); in other words, the Astatoreochromis condition (see above). Furthermore, accordingto Poll's account, there is no sexually dimorphic coloration in '//.' straeleni. There is another ' Haplochromis' species, '//'. vanderhorsti Greenwood, 1954 (Malagarasi river,Tanzania) which closely resembles straeleni in all the characters under consideration, differingonly in its slightly lower dorsal fin spine count (16 or 17), and in none of the 54 specimens exa-mined having 4 anal fin spines; its lower pharyngeal bone and dentition are more massive thanthose of straeleni (i.e. like the condition in A. alluaudi of the same size). The resemblances between'//.' vanderhorsti and A. alluaudi, and those between '//.' straeleni and '//.' vanderhorsti have beennoted already (Greenwood, 1954 : 405-407; \959a : 166-167), but were not analysed in terms oftheir apo- or plesiomorphy, and no conclusion was reached about the interrelationships of thespecies or their formal taxonomic status. Apart from the increased number of dorsal fin spines (and the four-spined individuals of'//.' straeleni), the only other shared, and probably derived, characteristic common to the threespecies is the enlarged lower pharyngeal bone and its at least partly molariform teeth (again atrend character, least developed in straeleni, most developed in Astatoreochromis alluaudi, andone which is known to have evolved independently in several haplochromine lineages). But,taking into account the virtually identical, non-sexually dichromatic coloration of the threespecies (and the ubiquity of sexual dichromatism alongst fluviatile haplochromines) the mostparsimonious solution would be to consider alluaudi, straeleni and vanderhorsti as being moreclosely related to one another than any one of them is to any other lineage. On these grounds I would agree with Poll's (1974) inclusion of'//.' straeleni in Astatoreochromisand would now include '//.' vanderhorsti in that genus as well. Contained species Astatoreochromis alluaudi Pellegrin, 1903 (Type species). Lakes Victoria, Kioga, Edward, George, Nabugabo, Kachira, and Nakavali; rivers and streams associated with these lakes. The species has been widely distributed in Kenya, Uganda and Tanzania as a biological control agent against snails (McMahon, Highton & Marshall, 1977). For a full description of the species see Greenwood (1959a), and for evidence invalidating the two subspecies described in that paper see Greenwood (19650). Astatoreochromis straeleni (Poll), 1944. Lukuga and Ruzizi rivers, Lake Tanganyika drainage.See Poll (1974) for a redescription of the species. Astatoreochromis vanderhorsti (Greenwood) 1954. Malagarasi river and swamps, LakeTanganyika drainage. A REVISION OF THE HAPLOCHROMIS GENERIC CONCEPT 287 CTENOCHROMIS Pfeffer, 1 893 TYPE SPECIES: Ctenochromis pectoralis Pfeffer, 1893 (type specimens in Hamburg Museum andBMNH). Description Body relatively deep to relatively slender (depth 30-40 % of standard length). Squamation. Scales on the body below the upper lateral line are strongly to moderately ctenoid(weakly ctenoid in one species, C. horii}, becoming cycloid over the posterior half of the body.Scales above the upper lateral line show the same range of ctenoidy or are all cycloid, the kindof scale being constant intraspecifically and positively correlated with those below the lateral line.Scales on the head and, when present, on the cheek, are cycloid. 3mmFig. 9 Thoracic-abdominal scale transition in Ctenochromis pectoralis. Left lateral view. The cheek always has a naked area along its ventral margin; in one species this area is less than ascale row in depth, in two others it is from 1 to 3 horizontal scale rows deep, and in a fourth virtuallythe whole cheek is naked, a few scales remaining immediately below and, or, behind the orbit. Along or slightly behind a line joining the pectoral and pelvic fin bases there is an abrupt sizetransition between the very small scales on the chest and the much larger scales on the lateral andventrolateral aspects of the body (Fig. 9). The chest has a well circumscribed naked patch on each side of the body (Fig. 9), the two patchesjoined in some species by a ventral naked area. The size of the naked patch shows some interspecificvariability, from a small and ventrolaterally situated area, to one covering most of the lateral andventrolateral (but not the medial) aspects of the chest. There are 27-33 scales in the lateral line series (modal numbers 30 and 31 for the two speciesfrom Tanzania, and 28-30 for the three Zaire river system species (see p. 290 below)) ; the last 8-12(usually 8 or 9) pored scales in the upper lateral line are separated from the dorsal fin base by lessthan two scales of approximately equal size. Neurocranium. The neurocranium is apparently of the generalized type (see Fig. 6), but in atleast one species (C. horii; Fig. 10) its preotic region is more elongate (c. 68-70% of neurocraniallength) and in others the preorbital region is slightly vaulted. Since little skeletal material isavailable these remarks are based mainly on radiographs and should be checked on actualskeletons. 288 P. H. GREENWOOD Vertebral numbers: 25-29 (modal range 27-28), comprising 12 or 13 abdominal and 13-17caudal elements (see p. 290 below). Dentition. The outer teeth are unequally bicuspid, or, in two species, subequally bicuspid, arerelatively stout and firmly attached to the underlying bone. Some posterior premaxillary teeth (asmany as 16 on each side in C. horii) are unicuspid, caniniform and relatively larger than the pre-ceding bicuspids. The crowns of the bicuspid teeth are not noticeably compressed, nor are theysharply demarcated from the shaft of the tooth; the cusps are acutely pointed. The inner teeth are small and tricuspid, and arranged in 2 or 3 series anteriorly and antero-laterally, but a single series posteriorly. 5mm Fig. 10 Neurocranium of Ctenochromis horii; left lateral view. Lower jaw. The dentary is relatively slender in lateral aspect, and not greatly deepenedposteriorly. Lower pharyngeal bone and teeth. The dentigerous surface is either triangular and subequilateral(slightly broader than long) in outline, or noticeably broader than long (c. 1 times; Fig. 1 1). Theteeth are cuspidate and compressed, those in the median and the posterior transverse row some-what stouter than the others (the degree of stoutness, especially of teeth in the two median rows,shows a positive correlation with the fish's size). Dorsal fin with 14-17 (modes 15 and 16) spinous and 8-10 (mode 9) branched rays. The holo-type of C. oligacanthus (Regan) has only 12 spines, but all other specimens have 15. Caudal fin skeleton. Because few dry skeletons or alizarin preparations are available, informa-tion on the caudal skeleton has been obtained mainly from radiographs. The difficulty of differen-tiating between fused and closely apposed hypural elements as seen in radiographs makes theseobservations of limited value. Ctenochromis pectoralis (10 specimens radiographed) has all five hypurals free. C. horii. Seven specimens (radiographed) have hypurals 1 and 2, and 3 and 4 fused, as doesthe dry skeleton examined. Two other specimens (radiographed) have hypurals 1 and 2 free, but3 and 4 fused. Vandewalle (1973) found no fused hypurals in the two specimens he examined. C. polli (2 specimens radiographed) has all hypurals free. C. oligacanthus. Of the three specimens radiographed, one (the holotype) has all hypurals free,one has hypurals 1 and 2 free but 3 and 4 fused, and the third has hypurals 1 and 2, and 3 and 4fused. Caudal fin is markedly subtruncate, almost rounded in some species. Pelvic fin with the first branched ray the longest. Anal fin markings in male fishes. Where known (3 of the 5 species) from preserved and, or, livingspecimens, these are in the form of one or two (rarely three) brilliant white or yellow spots, with-out a dark margin and without a clear surround (cf. Haplochromis and Astatotilapia, p. 279 and A REVISION OF THE HAPLOCHROMIS GENERIC CONCEPT 289 p. 283 respectively). The spot or spots may be on the anterior or the posterior part of the softfin with, apparently, their position constant intraspecifically. For a colour picture of C. polli seeVoss (1977 : 74). Gill rakers short and stout in all species except C. horii where they are long and slender ; thereare 7-9 rakers in the outer row on the first gill arch, except in C. horii where there are 10-13. Contained species Ctenochromis pectoralis Pfeffer, 1893 (Type species). Known only from streams in south eastern Tanzania, near Korogwe. 2mm Fig. 11 Lower pharyngeal bone of Ctenochromis polli. A. Occlusal view.B. Right lateral view (bone aligned vertically). Ctenochromis horii (Giinther), 1893. Lake Tanganyika and the coastal reaches of associatedrivers. See Poll (1956) for a detailed description and notes on biology. Ctenochromis polli (Thys van den Audenaerde), 1964. Pool Molebo (Stanley Pool) and thelower Zaire river. For coloured plate see Voss (1977). For notes regarding specimens formerlyidentified as H.fasciatus see p. 293. Ctenochromis oligacanthus (Regan) 1922. Ubangi river, an affluent of the Zaire river. The holo-type and sole specimen available to Regan has only 12 dorsal fin spines and 9 branched rays; thetwo additional specimens I have examined have 1 5 spines and 9 branched rays. Ctenochromis luluae (Fowler), 1931. Lulua river, Kasai drainage system, lower Zaire. I haveexamined four paratypes, and on the basis of that material would consider the species to be dis-tinct from C. polli and C. oligacanthus (the other two Ctenochromis from the lower Zaire drainage),and from C. pectoralis and C. horii. Diagnosis and discussion Members of the genus Ctenochromis are characterized by the abrupt size transition between thevery small chest scales and the larger scales on the ventrolateral aspects of the anterior flanks, bya naked area on either side of the chest, and by a failure of the cheek squamation to reach theventral margin of the cheek. (In one species, C. horii, the entire suborbital region of the cheekis scaleless in some individuals and in others there is, at most, no more than a single scale rowbelow and behind the orbit.) In three of the five species the anal fin markings of male fishes arein the form of one or two (rarely three), relatively small and simple, non-ocellate spots ; no infor-mation is available on the other two species. 290 P. H. GREENWOOD Virtually nothing is known about the biology of Ctenochromis species, which are, with theexception of C. horii, very poorly represented in study collections. Four of the five species arefluviatile and reach a small adult size (80 mm standard length); their feeding and breeding habitsare unknown. The fifth species, C. horii, is essentially lacustrine, reaches a larger adult size(185 mm SL) and is at least partly piscivorous. The geographical range of Ctenochromis extends from Tanzania in the east to the Zaire drainage(including Lake Tanganyika) in the west and lies between the latitudinal limits of c. 3 N and 8 S. Various apomorph features shown by Ctenochromis suggest its relationships with two othergenera; this problem will be discussed later (see p. 313). Intrageneric relationships are difficult to determine, partly because the small size of somespecimens limited the amount of anatomical information that could be obtained, partly because ofthe mosaic interspecific distribution of certain presumed apomorph characters, and partly becauseother characters form part of a morphoclinal continuum. $oth C. pectoralis (eastern Tanzania) and C. horii (Lake Tanganyika) have, relative to C. polliand C. oligacanthus, higher caudal vertebral counts (15-17, modes 16 and 17, cf. 13 and 14) andhigher lateral line scale counts (29-33, modes 30 and 31, cf. 27-29, mode 28); these featuresshould probably be considered plesiomorph ones (see p. 276 ). Ctenochromis pectoralis has relative-ly small naked patches on the chest (Fig. 9), and only the lower part of the cheek is scaleless.In comparison, C. horii has a large naked area on the chest and almost the entire cheek is withoutscales; the neurocranium in this species departs somewhat from the basic type found in C. pectora-lis (see Fig. 10 and p. 287) in having larger preorbital and preotic proportions, and individualsreach a larger size than in C. pectoralis. On these grounds I would consider C. horii to be thederived sister species of C. pectoralis. Ctenochromis polli (Stanley Pool and the lower Zaire river) and C. oligacanthus (Ubangi river,Zaire drainage) both have a reduced number of caudal vertebrae (13 or 14), fewer lateral linescales (27-29) and fewer branched anal fin rays (6 or 7 cf. 8 or 9 in C. pectoralis; C. horii with 7(mode) or 8 anal rays occupies an intermediate position). The third lower Zaire species, Ctenochromis luluae (Lulua river), however, also has an inter-mediate number of anal fin rays (7 or 8, mode 8), of lateral line scales (28-30) and of caudalvertebrae (15). The outer jaw teeth in C. polli, C. luluae and C. oligacanthus are similar and differ from thebasic, unequally bicuspid type found in C. horii and C. pectoralis in having the cusps subequal insize, with the tip of the smaller cusp directed away from the near vertical larger cusp. In bothC. polli and C. oligacanthus the dentigerous surface of the lower pharyngeal bone is noticeablybroader than long, whereas in C. pectoralis and C. horii its length and breadth are approximatelyequal (see Fig. 11); the bone in C. luluae has proportions that are intermediate between thesetwo types. Finally, the naked area of the chest in C. oligacanthus is much larger than in C. polli,but a greater area of the cheek is scaled in the former species. Most of the cheek is scaled inC. luluae, and the naked chest area is intermediate between that of C. polli and C. oligacanthus. On the basis of their dental morphology I would suggest that C. polli, C. luluae and C. oliga-canthus together form the sister group to C. pectoralis and C. horii; C. pectoralis would seem tobe the least derived taxon of the lineage. As a postscript to this discussion it may be mentioned (with the reservations noted on p. 282)that hypural fusions in Ctenochromis species are relatively common, and certainly commonerthan in Haplochromis, Astatotilapia and the ' Haplochromis' species of Lake Victoria (see p. 276above, and Greenwood, 19746 : 159). THORACOCHROMIS gen. nov. TYPE SPECIES: Paratilapia wingatii Boulenger, 1902 (see Greenwood, 1971 for a redescription ofthe species). ETYMOLOGY. The name is derived from the latinized Greek word for a breastplate + chromis, aname when used in such a combination now associated with many genera of African Cichlidae; A REVISION OF THE HAPLOCHROMIS GENERIC CONCEPT 291 it refers to the small and clearly size-demarcated scales on the thoracic region of species in thislineage. Description Body form ranging from relatively deep to relatively slender (depth 30-40% of standard length).Squamation. In the majority of species, the scales on the body above and below the upperlateral line, and behind a line through the pectoral and pelvic fin insertions, are ctenoid. A fewspecies have cycloid scales above the upper lateral line, and weakly ctenoid scales below it. Scaleson the cheek, head and chest are cycloid. The scales on the chest are small to very small and meet, with an abrupt change in size, the largerscales on the lateral and ventrolateral aspects of the flanks (Fig. 2). Generally the line of thisabrupt size change lies approximately between the insertions of the pectoral and pelvic fins, butmay be a little behind or, less frequently, a little before that level. The chest is always completelyscaled, although in two species the scales are so small and deeply embedded that the area appearsto be naked. The cheek is completely or almost completely scaled (in two species there is a very narrow,horizontal naked strip along the ventral margin, and in several other species there is a nakedembayment at the anteroventral angle of the cheek squamation). There are 29-32 (modal range 30-32) scales in the lateral line series; about the last eight pore-bearing scales of the upper lateral line are separated from the dorsal fin base by not more than onelarge and one much smaller scale. Neurocranium. Most Thoracochromis species have a skull form that departs but slightly fromthe type found in Ctenochromis (see p. 287). That is, a generalized type (see p. 274) in which thepreotic region of the neurocranium comprises some 65-70 % of the total neurocranial length. The most marked departure from this skull form is seen in two species, Th. bullatus (LakeAlbert) which has a greatly inflated otic capsule and somewhat enlarged lateral line sensorycanals, and Th. macconneli (Lake Turkana) where the sensory canals are hypertrophied and thebraincase is shallower. Thoracochromis demeusii (Zaire) deviates in a different way; here the supraoccipital crest isdeepened, extends further anteriorly than in the other species and has a steeper slope to itsanterior margin. These features may all be associated with the pronounced dermal hump develop-ed in the nuchal region of this species. Vertebral numbers: 26-31 (modes 28 and 29), comprising 12-14 (modes 12 and 13) abdominaland 13-17 (modes 14 and 17) caudal elements. With one exception (Th. moeruensis) the lowermodal counts for caudal vertebrae are found in fluviatile species from the Zaire river drainagesystem, the higher ones in species from Lakes Turkana, Albert, George and Mweru. Dentition. Unequally bicuspid or unicuspid, caniniform outer teeth are the the most frequentlyoccurring types. The crown in bicuspids is not noticeably compressed, and the cusps are acutelypointed. Unicuspid teeth may be recurved or almost straight; where the material covers a suffi-ciently wide size range of specimens it shows that the unicuspid dentition is preceded by a bicuspidone. Fishes in all species with a bicuspid definitive dentition have a few (1-6) unicuspids pos-teriorly on the premaxilla, these teeth generally being larger than the anterior bicuspids. In two species (Th. fasciatus and Th. loati} the outer teeth, although unequally bicuspid, havethe major cusp obliquely truncate, somewhat protracted and relatively compressed; the minorcusp is much reduced and is also obliquely truncate. Thus there is a close resemblance betweenthese teeth and those in Haplochromis lividus and H. Umax (see Fig. 7C and p. 281 above; alsoGreenwood, 1971 : 360, fig. 5). The inner teeth generally are tricuspid and in both jaws are arranged in 2 or 3 series anteriorlyand laterally, but in a single series posteriorly. In those species with unicuspid outer teeth at leastthe outermost row of the inner series contains some unicuspids, a mixture of tri- and unicuspids,or it may be composed entirely of unicuspids. Lower jaw relatively slender in lateral outline and not obviously deepened posteriorly.Lower pharyngeal bone and teeth. With respect to the outline shape of the dentigerous area,two fairly distinct types of pharyngeal bone occur in this genus. One type (found in species of 292 P. H. GREENWOOD the Zaire drainage, including Th. moeruensis but excluding 77?. demeusii) has the surface clearlybroader than long (Fig. 12). The second type (in species from Lakes Turkana, Albert and George)has its dentigerous surface only slightly broader than long, i.e. about 1 \ times. In all species the median tooth rows are noticeably coarser than their lateral congeners, andare even coarser than those in the posterior transverse row. Some species have stout and molari-form or submolariform teeth in the median rows, and in three other species (77?. albertianus,Th. mahagiensis and Th. pharyngalis) teeth lateral to the median rows are also enlarged andsubmolariform to molariform, (see Trewavas, 1938 : 441 and 444; Poll, 1939 : 47; Greenwood,1973 : 213). Associated with this enlargement of the dentition (especially in Th. mahagiensis andTV/, pharyngalis) the lower pharyngeal bone is markedly thickened. 3mm Fig. 12 Lower pharyngeal bone of Thoracochromis bakongo. A. Occlusal view.B. Right lateral view (bone aligned vertically). Teeth other than the enlarged ones are compressed and cuspidate in all species. Dorsal fin with 13-16 (modal range 14-16), rarely 17, spinous and 8-10 (modes 9 and 10),rarely 1 1 , branched rays. Anal fin with 3 spines and 6-10 (modal range 7-9) branched rays. Caudal fin skeleton : the distribution of fused hypural elements amongst Thoracochromisspecies, as determined mainly from radiographs, is as follows: (i) Lake Albert species, and those from the Nile and Lake George: no fusion in Th. wingatii(holotype), 77?. albertianus (6 specimens), 77?. mahagiensis (1), 77?. avium (holotype), Th. bullatus(13), 77?. loati (16) and Th. petronius (12); some specimens in most species have certain hypuralsvery closely apposed. (ii) Lake Turkana. 77?. rudolfianus has all hypurals free in 28 specimens examined, but hypurals1 and 2 are closely apposed or perhaps fused in two others; 77?. turkanae (4 specimens) has allhypurals free; in 77?. macconneli 6 of the 26 specimens examined have all hypurals free, 4 havehypurals 1 and 2, and 4 and 5 fused, 1 1 have hypurals 1 and 2, and 3 and 4 fused, but hypural5 free, and 5 have only hypurals 1 and 2 fused. (iii) Lower Zaire drainage, and Lake Mweru. Th. moeruensis has hypurals 1 and 2, and 3 and 4fused (6 specimens). 77?. demeusii (holotype) has all free; Th.fasciatis (6 syntypes) has all free, asdoes 77?. bakongo (3 specimens); Th. stigmatogenys has 2 specimens with hypurals 3 and 4 fused, A REVISION OF THE HAPLOCHROMIS GENERIC CONCEPT 293 and 4 others with all hypurals free. Vandewalle (1973) reports no fusion in the two species heexamined, namely, Th. bakongo and Th.fasciatus. Caudal fin subtruncate to almost rounded, most species being in the latter category. Pelvic fin with the first branched ray the longest. Anal fin markings. Regrettably little information is available on this character, either from liveor preserved specimens. True ocellar spots (3-8 in number) are present in Th. petronius (LakeGeorge) and apparently in the three species from Lake Turkana, although the clear surround inthese latter species is much narrower than in the ocelli of Haplochromis and Astatotilapia. Thefour species from Lake Albert and the Nile for which data are available (i.e. Th. albertianus,Th. bullatus, Th. wingatii and Th. loati) do not appear to have any clear area around the small,coloured or white spots, which are relatively large, well defined and number from 1 to 3. However,these observations were made on preserved material only and, since the whole fin is somewhatpigmented, a narrow hyaline surround could well be overlooked. No information is available for the remaining species (Lake Mweru and the Zaire riverdrainage). Gill rakers are of various shapes, with 6-12 (modal range 7-9) in the outer row on the first gillarch. Contained species Thoracochromis wingatii (Blgr.), 1902, type species; see Greenwood (1971) for a redescription and definition of the species. Upper Nile (Bahr-el-Jebel) and probably Lake Albert also. Thoracochromis loati (Greenwood), 1971. Upper Nile (Bahr-el-Jebel) and Lake Albert. Thoracochromis rudolfianus (Trewavas), 1933. Lake Turkana. Thoracochromis turkanae (Greenwood), 1974. Lake Turkana. Thoracochromis macconneli (Greenwood), 1974. Lake Turkana. See Greenwood (19746) for notes on the biology of the last three species, and for commentson their relationships. Thoracochromis albertianus (Regan), 1929. Lake Albert. Thoracochromis mahagiensis (David & Poll), 1937. Lake Albert (see also Greenwood, 1971 :356). Thoracochromis avium (Regan), 1929. Lake Albert. I follow Trewavas (1938) in consideringHaplochromis lanceolatus David & Poll, 1937, a synonym of this species. Thoracochromis petronius (Greenwood), 1973. Lake George, Uganda. Thoracochromis pharyngalis (Poll), 1939. Lake Edward. See Greenwood (1973 : 213) for a dis-cussion on the relationship of this species. Thoracochromis moeruensis (Blgr.), 1899. Lake Mweru. Thoracochromis demeusii (Blgr.), 1899. Lower Zaire river. See Thys van den Audenaerde (1964)for a redescription of the species and for other data; this author considers that the presumed typelocality (Bangala country, Upper Congo) is in error. Thoracochromis bakongo (Thys van den Audenaerde), 1964. Kasai drainage to the lower Zaireriver. Thoracochromis fasciatus (Perugia), 1892. Lower Zaire drainage at Vivi (538' S, 1330' E; seeThys van den Audenaerde, 1964). At present I am restricting the concept of this species to thesix syntypical specimens in the BMNH collections (reg. nos 1898.12.12:1-6). Certain other speci-mens in the BMNH collections identified as fasciatus, and at least part of the material on whichThys van den Audenaerde (1964) based his redescription of the species, are referable to one orpossibly two other species. These, or this, species differ from the syntypes of fasciatus in dentalcharacters and in having a graded rather than an abrupt size change between the chest and ventro-lateral flank scales (i.e. they cannot be referred to the genus Thoracochromis; see p. 291 above). Three further specimens in the BMNH collections (reg. nos 1899.9.6:2-4, ex Stanley Pool)which were included in fasciatus by Boulenger (1915 : 215-216) do, however, show an abruptsize change in the scales of this region. All 3 specimens are now in a very poor state of preservationbut, judging from certain morphometric characters and also from their dental morphology, itseems that they should be identified as Ctenochromis polli (see p. 289). 294 P. H. GREENWOOD Regan (1922a) tentatively included Paratilapia toddi Blgr., 1905 (Kasai river, Zaire drainage) inthe synonymy offasciatus. Regan's concept offasciatus was essentially that of Boulenger (1915)since his study material included the misidentified specimens noted above. The only knownspecimen of Paratilapia toddi, the holotype, is considerably larger (127-0 mm SL) than anymember of a known Thoracochromis species, and has the general facies and external cranialmorphology of a Serranochromis-like fish (see Trewavas (1964) who, indeed, thought that P. toddimight be related to Serranochromis). However, the holotype of P. toddi does show an abrupt sizetransition between the scales of the chest and flanks, and it also has a low number of caudalvertebrae (13) and a low branched anal fin ray count (7), features shared with some species ofThoracochromis (see p. 291 above). On the other hand, there are several features of P. toddi thatare not encountered in any member of that genus. Until more specimens are available it would seem best to treat P. toddi as a taxon incertae sedis;it certainly cannot be considered a synonym of Thoracochromis fasciatus. Thys van den Audenaerde (1964) considers Boulenger 's (1899) Chromis monteiri (from Boma)to be a synonym of fasciatus. Regrettably the holotype (and unique) specimen of C. monteiricannot now be found and so a comparison between it and the syntypes of Th. fasciatus could notbe made. But, judging from Boulenger's original description and figure, it seems highly improbablethat the specimens are from the same species. The possibility that monteiri holotype and some ofthe misidentified fasciatus material are conspecific cannot, however, be overlooked. Diagnosis and discussion Members of the genus Thoracochromis are characterized by the abrupt size transition betweenthe small chest scales and the much larger scales on the ventrolateral and ventral aspects of theflanks. This is, apparently, the only derived character shared by all members of the lineage.Several other derived features are, however, found in member species. For example, the obliquelytruncate tooth cusps in Th. loati and Th. fasciatus, the enlarged pharyngeal mills in 77?. mahagiensis,Th. albertianus and Th. pharyngalis, the bullate otic region in 777. bullatus, the hypertrophiedcephalic lateral line canals in Th. macconneli (and probably its near-dwarf males as well; seeGreenwood, 19746) and, finally, the short but broad lower pharyngeal bone in most species fromthe lower Zaire system. But, the restricted distribution of these apomorphic characters amongstthe species obliges one to rank them either as autapomorphies or as low level synapomorphiessuggesting possible intrageneric relationship (if, in the latter case, it can be shown that thecharacters have not evolved independently, an impossible task when there are no other featureson which to establish intrageneric relationships). Even the single synapomorphy used to define the lineage as a whole, the abrupt thoracic-flank scale size transition, is shared with Ctenochromis (p. 287) and Orthochromis (p. 296 below).The two latter lineages, however, have each their own derived features which can be interpretedas indicators of their monophyletic origin and thus their phyletic distinctiveness. The possible interrelationships of Thoracochromis, Ctenochromis and Orthochromis are con-sidered later (p. 313). Thoracochromis has a wide but disjunct geographical distribution. In the north there are threespecies endemic to Lake Turkana, and two others in the Nile, both of which also occur with thethree endemic species in Lake Albert. There is one species in Lake George, another in Lake Edward(with the possibility that the George species also occurs in Edward) and possibly a third in LakeVictoria. Much further south (and a little to the west) there is one species in Lake Mweru, and a groupof five species apparently confined to the lower Zaire drainage. From an historical viewpoint (Greenwood, 19746) the species of the Nile, Lake Turkana andLake Albert could well be closely related and could also be related to the species from LakesEdward and George. Indeed, 77?. mahagiensis (Lake Albert) and 777. pharyngalis (Lake Edward)have three apparently derived characters in common, viz. hypertrophied pharyngeal mills, a lownumber of gill rakers (as compared with other species from Lake Albert) and a reduced cheeksquamation; and again, 777. bullatus (Lake Albert) and 77?. macconneli (Lake Turkana) both have A REVISION OF THE HAPLOCHROMIS GENERIC CONCEPT 295 hypertrophied cranial lateral line systems, although in this instance, since both species live in deepwaters, the resemblance could be the result of parallel evolution. The lower Zaire species, with the exception of Th. demeusii, have distinctly broad and shortlower pharyngeal bones (that of Th. demeusii is but slightly broader than long and resembles thebone found in all other Thoracochromis species). Thoracochromis moeruensis, a geographicallyisolated Zairean species from Lake Mweru, also has a short and broad lower pharyngeal bone,suggesting its possible relationship with the lower Zaire species group (perhaps, geographicallyspeaking, through some past linkage via the Kasai drainage system). More collecting in the Zaire river system, especially its middle reaches, and more informationabout the northern (i.e. Nile, Turkana, Albert) species is needed before any of these suggestedintralineage groups can be developed further, and indeed before the phyletic integrity of the wholelineage can be tested adequately. Data on live coloration, anal fin markings and cranial osteologyare particularly needed. The absence, save for two or possibly three species of Thoracochromis from the Lake Victoria-Edward-George-Kivu cichlid flock (totalling some 200 species), is of particular zoogeographicalinterest, especially when it is recalled that in Lakes Turkana and Albert species of Thoracochromisare the only 'Haplochromis' -group taxa represented. Likewise one may note the predominance ofThoracochromis, Ctenochromis and Orthochromis species in the Zaire river system. ORTHOCHROM1S Greenwood, 1954 TYPE SPECIES: Haplochromis malagaraziensis David, 1937 (type specimens in the Musee Royal de1'Afrique Centrale, Tervuren). Synonymy Rheohaplochromis Thys van den Audenaerde, D. F. E. (1963), Revue Zool. Bot. afr. 68, 1-2 : 145(as a subgenus of Haplochromis); idem (1964), Revue Zool. Bot. afr. 70, 1-2 : 169 (raised togeneric rank). No type species by original designation. When discussing the affinities of Rheohaplochromis, Thys van den Audenaerde (1964: 169)mentions my observations (in Un.} that the genus showed strong affinities with Orthochromis.Although agreeing with my remarks, Thys van den Audenaerde considered that '. . . Pecaillurenuchale et ventrale vraiment miniscule des Rheohaplochromis (polyacanthus et torrent/cola) noussemble un caractere suffisamment important pour maintenir ces especes dans un genre separe . . .'.I would argue that the suite of derived characters shared by these species and the two other speciesdiscussed below (including O. malagaraziensis} are a stronger argument in favour of their in-clusion in a single lineage of presumed monophyletic origin (i.e. within the scope of this revision,a genus see p. 269 above). Thys van den Audenaerde's supplementary argument for placing the species polyacanthus andtorrenticola together in a separate genus (because of their overlap in distribution as comparedwith the allopatric distribution of the other Zaire haplochromine species) might well be used toexplain the presence of derived features shared only by polyacanthus and torrenticola, but itseems to have little bearing on the problem of determining their overall phyletic relationships. In an earlier paper, Thys van den Audenaerde (1963) considered that the small ventral andnuchal scales, and the rounded pelvic fins, of polyacanthus and torrenticola could be ecopheno-typic features associated with their rheophilic habits. In support of his contention he mentionssimilar features in Steatocranus, an unrelated taxon (see Greenwood, 1978). This argument ofecophenotypically evolved characters could also be used to explain the similar scale and fincharacters in the two other species I would include in the same lineage as polyacanthus andtorrenticola. But, to me, it would seem more parsimonious to conclude that, although the featurespossibly have selective advantage in a torrential habitat, their association in a number of speciessharing other derived features is more likely to be indicative of common ancestry than of repeatedparallel evolution. Since Steatocranus may well be a member of a much more distantly relatedbranching within the African Cichlidae (see Greenwood, 1978), the similarity in scale and fin 296 P. H. GREENWOOD organization in that instance would, I agree, be the result of convergence (and thus indicativeof the characters having adaptive value in that type of habitat). Description Body elongate and slender (its depth 25-30% of standard length); dorsal head profile strongly decurved, eyes generally suprolateral in position, giving the fish a somewhat goby-like appearance. Squamation. Scales on the head and on the body above the upper lateral line are cycloid orweakly ctenoid, or cycloid over the anterior third of the upper body and ctenoid over the posteriortwo-thirds. Scales below the upper lateral line are ctenoid except on the chest and belly, wherethey are cycloid. The chest is naked or scaled (if the latter there is sometimes a small naked area on one or bothsides of the body); the chest scales, when present, are very small, as are the scales on the ventraland ventrolateral body surface as far posteriorly as the anus (Fig. 3). The small ventral body scales have an abrupt size transition with the moderatley larger scales onthe ventrolateral aspects of the flanks. When the entire chest is scaled, the small scales of thatregion extend posteriorly beyond a line joining the pectoral and pelvic fin insertions (Fig. 3). There isalso a sharply defined size difference between the larger ventrolateral body scales and the smallthoracic ones, the line of size demarcation curving gently in a posteroventral direction to merge withthe demarcation line separating the belly and ventrolateral flank scales (Fig. 3). In effect, the corsletof small scales covering the chest trails backwards to the anus (cf. Ctenochromis and Thoracochromiswhere the corslet is confined to an area anterior to the pelvic-pectoral fin insertions). Even whenthe major part of the chest is naked, there is a patch of small scales between and somewhatposterior to a line through the pelvic and pectoral fin insertions; as in the other species, thesesmall scales are sharply demarcated from the larger ones on the flank. The nuchal scales in two species (O. polyacanthus and O. torrenticold) are very small and deeplyembedded. There are 30-35 (modal range 30-32) scales in the lateral line, all the pore-bearing scales of theupper lateral line being separated from the dorsal fin base by not more than one large and one smallscale (cf. Ctenochromis and Thoracochromis where only the last few scales of the upper lateralline are separated from the dorsal fin by less than two scales of equal size). The cheek is naked or, if scaled, has a distinct naked area along its entire ventral border; insome individuals with otherwise naked cheeks, a few irregularly arranged scales may occurposterodorsally. Neurocranium. The skull in Orthochromis differs from the generalized type in having a relativelylow and short supraoccipital crest, and in having the skull roof anterior to the supraoccipital crestgently rounded (not concave or flat as is the generalized skull) ; the entire neurocranium is relativelynarrow, most noticeably in the interorbital region, and the preorbital skull profile slopes downwardsat a steep angle. Vertebral numbers: 27-30 (modal range 28-30), comprising 12 or 13 (mode 13) abdominal and14-17 (mode 17) caudal elements. Dentition. The outer teeth in both jaws are either bicuspids (generally with the shaft of the toothcurved buccally) or slender unicuspids (in which case small fish have bicuspid teeth). Some slenderunicuspids are present posteriorly in the premaxilla of all species. Inner row teeth are small and tricuspid (with some unicuspids present when the teeth of theouter row are predominantly unicuspids), are arranged in 2 or 3 series anteriorly and laterally,and in a single row posteriorly. Lower jaw appears foreshortened in lateral view because its posterior region (angulo-articular boneand the cor onoid process of the dentary) are deepened relative to the generalized condition seen,for example in Astatotilapia. Lower pharyngeal bone and dentition. The dentigerous surface of the lower pharyngeal bone issomewhat broader than it is long (c. 1 times), but is not sufficiently broad to give the bone anoverall short and broad appearance. The teeth are compressed and cuspidate, those of the twomedian rows showing some interspecific variation in form, from not as coarse or slightly coarser A REVISION OF THE HAPLOCHROMIS GENERIC CONCEPT 297 than the lateral teeth, to being markedly coarser; teeth forming the posterior transverse row arecoarse (but cuspidate) in all species. Dorsal fin with 16-20 (modes 17 and 18) spinous and 9-1 1 (modes 9 and 10) branched rays. Anal fin with 3 or, in one species, 4 spines, and 7-10 branched rays. Caudal fin skeleton. The occurrence of fused hypural elements (as determined from radio-graphs, and in the case of O. malagaraziensis an alizarin preparation) is as follows : in O. mala-garaziensis (7 specimens, including 1 paratype), O. polyacanthus (11) and O. machadoi (2),hypurals 1 and 2, and 3 and 4 are fused, but in O. torrenticola (2) none is fused although all areclosely apposed to one another in each half of the skeleton. Vandewalle (1973) records no fusionin the specimen of O. torrenticola he examined. Caudal fin is moderately to strongly subtruncate (almost rounded). Pelvic fin with the second, or the second and third branched rays the longest, thus giving the fin arounded rather than an acute distal margin. Anal fin markings in male fishes. No discrete, egg-dummy-like markings have been described forany Orthochromis species, nor are any visible in the preserved material examined ; certainly nonewas visible in the live specimens of O. malagaraziensis I examined (Greenwood, 1954). In somespecies the fin is without any form of maculate colour pattern so that if egg-dummies were presentthey should be visible. Orthochromis torrenticola does have a maculate anal fin (the spots arrangedin oblique rows) and Thys van den Audenaerde (1963) reports that males have more denselyspotted fins that do females. Observations on live O. malagaraziensis suggest that sexually dimorphic coloration in thatspecies may be confined to differences in the colour of the lips, anal fin, and branchiostegalmembrane (Greenwood, 1954). Gill rakers relatively slender but short, 6-9 (modes 7 and 8) in the outer row on the lower partof the first gill arch. Contained species Orthochromis malagaraziensis (David), 1937. Malagarasi river (Burundi and Tanzania); see Greenwood (1954) for a redescription of the species and notes on its biology. Orthochromis polyacanthus (Blgr.), 1899. Lake Mweru, Upper Zaire river (Stanley Falls andStanleyville, and certain affluent rivers (see Thys van den Audenaerde, 1963)). I have, for themoment, accepted Regan's (19220) synonymy of Boulenger's (1902) Tilapia stormsi with thisspecies; however, a review of material in the BMNH suggests that Regan's opinion may not becorrect. Orthochromis torrenticola (Thys van den Audenaerde), 1963. Lufira river (Upper Zaire riverdrainage). Orthochromis machadoi (Poll), 1967. Cunene river, Angola. Diagnosis and discussion Members of the genus Orthochromis are characterized, principally, by the abrupt size changebetween the large scales on the ventrolateral aspects of the flanks and the small scales of the chestand belly, by the curved and posteroventrally directed line of size demarcation between these scales,and the union of this line with that separating the very small scales on the belly from the largerscales on the flanks, see Fig. 3. The very small belly scales, extending backwards to the anus,are another characteristic feature. Also characteristic (when taken in combination with thosecharacters listed above) is the absence or extensive reduction of the cheek squamation, theposteriorly deepened lower jaw, the increased number of spinous rays in the dorsal fin (without acorresponding reduction in the number of branched rays, this comparison being based on themodal counts for branched rays in Ctenochromis and Thoracochromis], the elongate second orsecond and third branched rays in the pelvic fin and, apparently, the absence of egg-dummy-likemarkings on the anal fin of adult males. Other diagnostic features are reviewed on pp. 295-296 above; the high frequency of hypuralfusion, affecting both the upper and lower halves of the caudal fin skeleton, is particularly note- 298 P. H. GREENWOOD worthy but requires confirmation from larger samples and the use of skeletal rather than radio-graphed material. The absence of egg-dummy-like markings on the anal fin also requires confirmation fromobservations made on live specimens (their absence in O. malagaraziensis, however, seemscertain; Greenwood (1954)). This is a most unusual feature amongst 'Haplochromis' -groupspecies, and may imply that the courtship and breeding habits of Orthochromis species are alsounusual for the group. Until something is known about these habits in Orthochromis it is impossibleto determine whether the absence of egg-dummies is to be considered a primitive or a derivedfeature for the genus. I am unable to demonstrate any clear-cut interspecific relationships within the Orthochromislineage. Orthochromis machadoi (Cunene river) is probably the least derived member. It has apartly scaled cheek, the chest is either entirely scaled or, as in one specimen, it can have a smallscaleless area unilaterally, the ventral (belly) body scales are relatively large and, finally, in itsgeneral facies the species has not fully achieved the elongate goby-like body form seen in the otherspecies. In his original description of O. machadoi, Poll (1967) argues that the species is closely relatedto Pseudocrenilabrus philander (Weber) an opinion I cannot accept (especially since Poll's viewsare, it seems, largely based on supposed similarities in coloration). Anatomically, and with regardto their squamation patterns, the taxa are quite distinct. The preserved colours of O. machadoi, on the other hand, are like those of O. malagaraziensis.Both species have all the body scales (except on the chest and belly) narrowly outlined in black,giving the body an overall 'diamond-mesh pattern; they also have a distinctive and verticallyelongate dark blotch at the base of the caudal fin. In O. torrenticola this diamond-mesh pattern is very faint but general over the body, whereasin O. polyacanthus it is restricted to a pair of narrow bands, one situated midlaterally, the otherfollowing the upper lateral line. Orthochromis torrenticola retains the caudal spot which is lost inO. polyacanthus. Both species have the body crossed by several closely spaced vertical bands. Theapo- or plesiomorph states of these colour patterns cannot be determined. Orthochromis torrenticola and O. polyacanthus have minute scales on the dorsal surface of thehead and nuchal region (in O. machadoi and O. malagaraziensis these scales are only slightlysmaller than those on the dorsal body surface), and the scales on the thoracic region are relativelysmaller than in the other two species, especially O. machadoi. In other words, O. torrenticola andO. polyacanthus share derived features in their squamation. If these various characters can be taken as indicators of relationship, then O. machadoi andO. malagaraziensis would be sister species, as would O. torrenticola and O. polyacanthus. But, onemust set against these similarities the fact that the chest and cheek are naked (or largely naked)in O. malagaraziensis and O. torrenticola, and that both species have similar general facies(sharply decurved anterior head profile, elongate body and a suprolateral eye), all features whichwould appear to be derived rather than plesiomorph ones. The four anal spines in O. torrenticolamust be considered an autapomorphic feature and as such cannot be used to assess relationships. Orthochromis, Ctenochromis and Thoracochromis share one derived feature, the abrupt sizetransition between chest and body scales, and thus are presumed to be derived from a commonancestor also possessing this feature. However, no synapomorph character can be found to indi-cate which two of the three genera are more closely related to one another. Since Thoracochromis has only one apomorph feature (chest-body scale size transition), acharacter shared by all three taxa, it can on that basis be considered to represent the least derivedmember of the group. Ctenochromis and Orthochromis both exhibit, but do not share, a number of derived featureswhich must, therefore, be considered autapomorphic for the lineage in which they occur (anddefine). If one were to consider 'trend' characters, for example a tendency to reduce cheek andchest squamation, then Ctenochromis and Orthochromis could be said to share some derivedfeatures not shared with Thoracochromis. But, I can find no trenchant synapomorphic characterthat would allow one to establish an unequivocal sister-group relationship between the two taxa.It is for this reason that I have given each lineage in this ultimately monophyletic assemblage the A REVISION OF THE HAPLOCHROMJS GENERIC CONCEPT 299 status of a genus (see p. 269) rather than ranking Orthochromis and Ctenochromis as subgenera(i.e. implicit sister-groups) on the grounds of their having shared and presumed apomorph 'trend'characters. Section II Although several of the species dealt with in this section have previously been referred to thegenus Haplochromis (see Bell-Cross, 1975), at least one author (Trewavas, 1964) has suggestedthat these same species, together with the genera Serranochromis and Chetia, are more closelyrelated to one another than to any of the species already accounted for. In part I would agreewith Trewavas' groupings, but the available evidence does not allow one to substantiate, in theirentirety, the relationships indicated in her phyletic diagram (Trewavas, 1964 : fig. 1), nor is itpossible to determine the relationships of these 'southern' taxa with the more northern 'Haplo-chromis' -group genera considered in Section I. SERRANOCHROMIS Regan, 1920 TYPE SPECIES. Chromys thumbergi Castelnau, 1861 (neotype, designated by Trewavas (1964), inBMNH collections). I have united several species (those previously placed in this genus by Trewavas (1964) andothers placed in Haplochromis by Bell-Cross (1975)) into one lineage (= genus) because all sharethe following apparently derived features: (i) A high number of abdominal vertebrae, 16-18, rarely15 or 19 (modal numbers 16 and 17). (ii) A large number of gill rakers, 9-15 (modal range 10-13)in the outer row on the lower part of the first gill arch, (iii) A high number of branched fin raysin the dorsal fin. In addition, members of this lineage reach a large adult size, all have cycloid or a mixture ofcycloid and weakly ctenoid scales (the ctenii confined to a small median sector on the scale'sposterior margin) in which the cycloid kind predominate, and the anal fin markings (egg-dummies)in males are numerous, small and non-ocellate (in some species differing little in size, shape orcolour from the spots on the soft part of the dorsal fin). It is not, however, possible to assess theprimitive or derived states of these features which, therefore, are of no direct value in assessingphylogenetic affinities, (but see p. 274 regarding egg-dummies.) Two sublineages, each based on shared derived features common to their constituent species,can be recognized within the genus Serranochromis, and these are given subgeneric rank. Subgenus SERRANOCHROMIS Regan, 1920TYPE SPECIES. Chromys thumbergi Castelnau, 1861. Description The body form varies from deep to moderately slender (body depth 30-45 % of standard length). Squamation. The scales on the head, chest, cheek and above the upper lateral line are cycloid,those elsewhere on the body mostly cycloid. When ctenoid scales are present these are weaklyctenoid, with the ctenii confined to a short median sector on the free margin of the scale. The scales on the chest (which may be relatively small) show a gentle size gradation with thoseon the lateral and ventrolateral aspects of the flanks; the chest is always fully scaled. The cheek is fully scaled, with from 3 (rare) to 11 horizontal rows of scales (usually 5-9 rows}. There are 35-41, rarely 34 scales in the lateral line, all but the last 2 or 3 pore-bearing scales ofthe upper lateral line are separated from the dorsal fin origin by two scales of approximately thesame size. Neurocranium. The skull has a protracted preotic region (comprising some 65-70 % of the totalneurocranial length), especially noticeable in the ethmovomerine region which comprises c. 27-33%of the total neurocranial length. The ethmovomerine part of the skull is almost horizontally aligned,its dorsal surface sloping at a small angle (Fig. 13). The supraoccipital crest is variously developed,high in some species, relatively lower in others but never shallow relative to the total skullproportions. 300 P. H. GREENWOOD Vertebral numbers and apophysis for the dorsal retractor muscles of the upper pharyngealbones. There are 31-36 vertebrae, comprising 16-18, rarely 15 or 19 (modes 16 and 17) abdominaland 16-18, rarely 15 (modes 16 and 17) caudal elements. Such a high number of both caudal andabdominal vertebrae is rarely encountered amongst ' Haplochromis' '-group cichlids, and is uniqueamongst the fluviatile taxa (see, also p. 313 below). An apophysis for the origin of the dorsal retractor muscles of the upper pharyngeal bones isdeveloped on the ventral face of either the 3rd or 4th abdominal vertebra; although the apophysisdoes occur on the 4th vertebra in other 'Haplochromis' -group taxa, it is usually confined to the3rd centrum (see Trewavas, 1964 for comments on this feature). 10mmFig. 13 Neurocranium of Serranochromis (Serranochromis) robustus; left lateral view. Dentition. The teeth in both the inner and the outer rows of the jaws are unicuspid, even in thesmallest (29 mm SL) specimens examined. Other l Haplochromis '-group species in which the adultdentition is a unicuspid one (and for which specimens less than 100 mm SL are available), havebicuspid outer teeth, and usually tri- or bicuspid inner teeth, in fishes less than 80-100 mm standardlength. The inner teeth are arranged in a single (rarely a double) row; when two rows are present, theseare confined to the anteromedial part of the jaw, the series continuing posteriorly as a single row. Inmany species the inner teeth of the lower jaw are confined to a narrow, anteromedial arc. Themajority of 'Haplochromis' -group taxa have a more extensive inner dental pattern, with the teetharranged in at least 2 (and usually 3) rows over the anteromedial and anterolateral parts of thejaw bones. Lower pharyngeal bone and teeth. With regard to its outline shape when viewed occlusally, twokinds of pharyngeal bone can be recognized (Fig. 14). In one, the commoner type, the bone is longand narrow, the dentigerous surface having the outline of an isosceles triangle (Fig. 14A & B). Thesecond type (found in two species) is relatively broader and its dentigerous surface, although stillslightly broader than long (c. \\ times) is more nearly equilateral (Fig. 14C). Irrespective of the bone's outline shape, the teeth (except those in the two median rows) arefine and either simply pointed or with a weakly developed shoulder anterior to the pointed cusp.The two median and the posterior transverse rows are made up of stouter teeth, those in themedian rows are relatively the stouter and have the shoulder more clearly demarcated than it isin the outer teeth. Jaws. The lower jaw is relatively slender in lateral view (Fig. 15B) and is not noticeably deepenedposteriorly (angulo-articular region). The premaxillae have, in most species, long ascending pro- A REVISION OF THE HAPLOCHROMIS GENERIC CONCEPT 301 Fig. 14 Lower pharyngeal bones of various Serranochromis (Serranochromis)species, seen in occlusal view. A. Serranochromis (S.) thumbergi.B. S. (S.) robustus. C. S. (S.) macrocephalus. cesses (Fig. 15 A) which, in the entire fish, extend to the level of the midpoint of the dorsal orbitalmargin or even further dorsoposteriorly. Dorsal fin: with 13-18 (modes 15 and 16) spinous, and 13-16 (usually 14-16) branched rays (ahigh branched ray count when compared with that in other fluviatile haplochromine taxa). Anal fin: with 3 spines and 9-73 (modes 10 and 11) branched rays (again, a high branched raycount). Caudal fin skeleton. No hypural fusion was noted in any of the radiographed material examined,i.e. S. macrocephalus (12 specimens), S. spei (1), S. robustus (14), S. longimanus (4), S. angusticeps(17), S. stappersi (1), S. meridionalis (1). No fusion was reported by Vandewalle (1973) in theS. macrocephalus (1) or S. robustus (1) he examined. 302 P. H. GREENWOOD Caudal fin: subtruncate (slightly emarginate in one species) to weakly rounded. Pelvic fin: with the first branched ray the longest. Anal fin markings in male fishes. Most species have many small, generally circular spots withouta clear surround and covering a large area of the soft anal fin, sometimes extending onto thespinous part as well. In their size and shape these spots are similar to those on the soft part of thedorsal fin and on the caudal fin. An exception to these generalizations is S. spei which has fewerand larger (but non-ocellate) spots covering the greater part of the soft fin. From the little information available on live coloration it seems possible that the anal spotsmay differ slightly from the dorsal fin spots in colour and intensity, but this requires confirmation.(For coloured illustrations, see Jubb (1967a, pis 41-44) and Bell-Cross (1976: pis 26-28). 10mm Fig. 15 Jaws of Serranochromis (S.) robustus; left lateral view.A. Premaxilla, B. Lower jaw. Trewavas (1964) reports that similar spots are present on the anal fin of females, but are greyrather than red, yellow or orange as in males. Where breeding habits are known, the species are female mouthbrooders. Gill rakers are of various forms, from short and stout to moderately slender; there are 9-13(modal range 10-12) rarely 8 rakers in the outer row on the lower part of the first gill arch. Contained species See Trewavas (1964) for detailed descriptions, figures, etc. Serranochromis (S.) robustus (Giinther), 1864. Lake Malawi, Upper Shire river; Mossamedes;Okavango; Upper Zambesi; Kafue river; Luangwa system (tributary of the Middle Zambesi);Bangweulu region; Luembe river, Kasai system (see Poll, 1967); possibly also in Lake Mweru andthe Lualaba system. Serranochromis (S.) thumbergi (Castelnau), 1861 (Type species). Mossamedes; Okavango riverand Lake Ngami; rivers Kafue and Luansemfwa (Luangwa system); Bangweulu region; Upembabasin. Serranochromis (S.) macrocephalus (Blgr.), 1899. Mossamedes; Okavango river; Lake Cameia(on an Angolan tributary of the Upper Zambesi); Upper Zambesi; Kafue river; Luansemfwariver, Luangwa system; Luapula river; Lake Mweru; Lulua river; Angolan Kasai. Serranochromis (S.) angusticeps (Blgr.), 1861. Mossamedes; Okavango river and Lake Ngamiregion, Upper Zambesi; Kafue river; Bangweulu region; Luapula river; possibly Lake Mweru(see also Poll, 1967). Serranochromis (S.) longimanus (Blgr.), 1911. Okavango river and the Upper Zambesi. Serranochromis (S.) stappersi Trewavas, 1964. Lake Mweru and the lower Luapula river. Serranochromis (S.) spei Trewavas, 1964. Lake Kafakumba (2340' E, 940' S) on a tributaryof the Kasai system; Lake Kabongo in the Lake Upemba depression. A REVISION OF THE HAPLOCHROMIS GENERIC CONCEPT 303 Serranochromis (S.} janus Trewavas, 1964. Malagarasi swamps (Malagarasi river), Tanzania. Serranochromis (S.) meridionalis Jubb, 1967. Incomati river system, Transvaal, South Africa(see Jubb, 19676). Dr Trewavas (1964) has discussed the possible affinities of these species (except S. meridionalis)at what should now be considered an intra-subgeneric level. Until more material is available foranatomical studies no further comment would be worthwhile. The relationships of the subgenuswith its sister-group (Sargochromis), and of the genus as a whole, will be considered below (p. 306). 10mm Fig. 16 Neurocranium of Serranochromis (Sargochromis) codringtoni; left lateral view. Subgenus SA RGOCHROMIS Regan, 1920. TYPE SPECIES: Paratilapia codringtoni Blgr., 1908 (type specimen in the collections of the BMNH,see Bell-Cross, 1975). Description Body deep and stout (depth 35-50% of standard length). Sargochromis differs from the nominate subgenus in the following characters : Squamation. There are fewer lateral line scales (28-34, modes 30 and 31, cf. 35-41 rarely 34). Neurocranium. Although basically of the same type as that in Serranochromis, most Sargo-chromis species have a somewhat shorter ethmoid region (but similar preotic skull proportions),a deeper otico-occipital region and, in some species, a more robust apophysis for the upperpharyngeal bones (Fig. 16). This latter character is positively correlated with the degree ofenlargement of the pharyngeal bones and the extent to which their dentition is molarized (seeGreenwood, 19650 and 1978). The more massive the pharyngeal bones the greater is the relativecontribution of the basioccipital to the articular surface of the apophysis, and in those specieswith the largest bones the prootic also contributes to that surface. Vertebral numbers. There are fewer caudal vertebrae (12-16, modal numbers 14 and 15), andhence a lower total count (28-32, mode 31). The number of abdominal vertebrae, however, is highin both subgenera. Jaws. The dentary differs from that in Serranochromis in being relatively more foreshortenedand thus deeper (Fig. 17). The premaxillary ascending processes do not extend beyond about themidpoint of the anterior orbital margin (beyond that point in most Serranochromis}. Dentition. Unlike small specimens of Serranochromis, small Sargochromis do have somebicuspid inner and outer teeth (at least some specimens < 10-15 cm, depending on the species, 304 P. H. GREENWOOD have predominantly bicuspid outer teeth). The dental pattern is similar in both subgenera, savethat S. (Sargochromis) thysi has 4 inner series in both jaws. Lower pharyngeal bone and teeth. The bone shows some interspecific variation in outline shape(Fig. 1 8) but is always relatively broader than in Serranochromis, and thus the dentigerous surfacemore closely approximates to the equilateral. In only one species, 5". (Sargochromis} greenwoodi(Fig. ISA), are there no markedly enlarged median teeth. Most of the other species have someenlarged, often submolariform, teeth in addition to those forming the two median rows. Generallythese enlarged teeth are restricted to a central patch, several tooth rows wide, in the posterior(oesophageal) dentigerous field. Two species, S. (Sargochromis) codringtoni and 5". (Sa.) giardi,have most of the pharyngeal dentition composed of coarse, molariform or submolariform teeth. 10mm Fig. 17 Jaws of Serranochromis (Sargochromis) codringtoni', left lateral view.A. Premaxilla, B. Lower jaw. Bell-Cross (1975 : fig. 1) described intrapopulational differences in the extent to which thepharyngeal dentition is enlarged. Most Sargochromis species have the lower pharyngeal bone coarser than it is in the nominatesubgenus, and markedly so when the pharyngeal dentition is hypertrophied. Dorsal fin has a lower modal branched ray count (12 or 13 cf. 14-16 in Serranochromis) butthere is an extensive overlap in the total ranges (11-16 cf. 13-16). There is also a broad overlapin spinous ray counts, although the higher numbers (17 and 18) recorded for the nominate sub-genus have not been reported for Sargochromis. Anal fin markings are essentially the same in both subgenera. For colour illustrations seeJubb (1967a : pis 40 and 45); Bell-Cross (1976 : pis 17 and 18). Caudal fin skeleton. No hypural fusion was seen in the radiographs of S. (Sa.) coulteri, S. (Sa.)greenwoodi, and S. (Sa.) codringtoni (1 specimen each); in 5. carlottae one specimen has hypurals3 and 4 fused but two other fishes show no fusion. Of the two S. (Sa.) mellandi examined, onehas hypurals 3 and 4 fused, but the other has none fused. Vandewalle (1973) records S. (Sa.)mellandi as having either no fusion (4 specimens) or hypurals 3 and 4 fused (2 specimens). Caudal fin strongly subtruncate to virtually rounded. Gill rakers are more numerous in Sargochromis (9-15, modal numbers 12 and 13). Contained species For a systematic review and notes on the ecology and distribution of the first seven species listed below see Bell-Cross (1975). Serranochromis (Sa.) greenwoodi (Bell-Cross), 1975. Upper Zambesi; Kafue system; Okavangosystem. Serranochromis (Sa.) coulteri (Bell-Cross), 1975. Upper Cunene system. A REVISION OF THE HAPLOCHROMIS GENERIC CONCEPT 305 A 5mm 5mm Fig. 18 Lower pharyngeal bone of : A. Serranochromis (Sargochromis) greenwoodi in a. Occlusal, and b. Right lateral view (bone aligned vertically). B. S. (Sa.) codringtoni; occlusal view. Serranochromis (Sa.) mortimeri (Bell-Cross), 1975. Upper Zambesi; Kafue river (above theLufwanyama-Kafue confluence); part of the Mulungishi river (a Middle Zambesi tributary). Serranochromis (Sa.) mellandi (Blgr.), 1905. Chambesi river and Lake Bangweulu; the Luapulariver and Lake Mweru; Lake Calundo, Angola (see Poll, 1967). Serranochromis (Sa.) carlottae (Blgr.), 1905. Upper Zambesi; Okavango and Kafue systems. Serranochromis (Sa.) codringtoni (Blgr.), 1905 (Type species of the subgenus). Upper and MiddleZambesi rivers (including the larger tributaries); Kafue and Okavango river systems. Serranochromis (Sa.) giardi (Pellegrm), 1904. Middle and lower regions of the Upper Zambesi;the Okavango and the plateau section of the Kafue river; one record from the Cunene system. Serranochromis (Sa.) thy si (Poll), 1967. Luembe river, Angola. 306 P. H. GREENWOOD Diagnosis and discussion Members of both subgenera comprising the genus Serranochromis are characterized by having ahigh modal number of abdominal vertebrae (16 or 17, rarely 15 or 19, modes 16-18) and thus ahigh total vertebral count (29-36), a high number of gill rakers in the outer row on the lower partof the first gill arch (10-15, rarely 9, modal range 10-13), a generally high number of brancheddorsal fin rays (11-16, modal range 12-16), mostly cycloid scales on the body (if some ctenoidscales are present they are weakly so), a high number of lateral line scales (28-41) as comparedwith other fluviatile 'Haplochromis '-group species and, at least in one subgenus, a greater numberof scale rows on the cheek (5-9), in having a skull with a relatively protracted preotic region andrelatively high supraoccipital crest, and in having numerous, small non-ocellate coloured spotson the anal fin of male fishes (these markings differing but slightly in size and colour from thoseon the dorsal fin). Diagnostic features for the two subgenera are detailed on pp. 299-301 & 303-304, and in thekey (p. 316). They involve, chiefly, the higher number of caudal vertebrae and branched dorsal finrays in Serranochromis (Serranochromis) species, and the stouter lower pharyngeal bones anddentition in Serranochromis (Sargochromis) species. Trewavas (1964) and Bell-Cross (1975) have considered intragroup relationships within thesubgenera Serranochromis and Sargochromis respectively. A reconsideration of their conclusionsis beyond the scope of this paper, although Trewavas' (1964 : fig. 1 and p. 10) grouping of theSerranochromis (Serranochromis) species would seem, on the basis of the characters used, to bea sound hypothesis. Trewavas (1964) also made an extensive analysis of the intergroup (i.e. intergeneric) relation-ships of what I am treating as the subgenus Serranochromis (treated by Trewavas as a genus). Shebrought into these considerations the 'genus' Sargochromis (S. codringtoni only) and three' Haplochromis* species (mellandi, frederici and carlottae) which are now referred to Sargochromis(as a subgenus of Serranochromis). In discussing Trewavas' ideas, unless quoting directly, I shalluse the terms ' Serranochromis', 'Haplochromis'' and ' Sargochromis' to cover her concept of thesetaxa. In Trewavas' view (1964 : also fig. 1, p. 8) 'Serranochromis'' is '. . . a gradal genus rather thana clade', of diphyletic origin from '. . . a small species-flock of Haplochromis' (i.e. the fourHaplochromis of Angola, '//'. lucullae, '//'. humilis, '//'. acuticeps and '//'. angolensis, plus 'H\darlingi of the Zambesi (see below, pp. 310-313). 'A cladal grouping,' Trewavas continues, 'would recognize Chetia, S. robustus and S. thumbergion the one hand, and H. welwitschii, S. macrocephalus and the other species of Serranochromison the other, but definitions would be almost impossible. . . . The broken line' (referring to fig. 1)'at the Haplochromis-Sargochromis transition reflects the absence here too of a clear genericdivision'. Because all 'Serranochromis' species share a high caudal vertebral count and other apparentlyderived features (see p. 299), I cannot accept Trewavas' concept of that taxon having a diphyleticorigin, nor can I accept, without considerable qualification, the inclusion of Chetia (i.e. C.flavi-ventris) and 'H.' welwitschii in one cladal grouping. Neither Chetia nor 'H.' welwitschii has thehigh caudal vertebrae count of 'Serranochromis' (i.e. the nominate subgenus recognized above)and, although these two species together with certain other endemic Angolan 'Haplochromis' and'//.' darlingi do share some features with Serranochromis, these are not of the kind that wouldsuggest a close cladistic relationship. The question of possible relationships between the Angolan species, '//.' darlingi and Chetiaflaviventris will be considered on pp. 312-313. Trewavas (1964 : fig. 1, p. 9) recognizes the phyletic affinity between Serranochromis andSargochromis (the latter now of course broadened to include the three 'Haplochromis' (see p. 305)species which she indicated as being more closely related to 'Sargochromis' than 'Serranochromis').We would differ, however, in our interpretation of the relationship between Sargochromis and'Haplochromis' darlingi. Trewavas (1964 : 9) writes of 'The evolutionary line which leads fromH. darlingi to Sargochromis . . .' But I can find only one derived character (the enlarged pharyn-geal mill) that might link 'darlingi' more closely with Sargochromis than with Serranochromis, A REVISION OF THE HAPLOCHROMIS GENERIC CONCEPT 307 and none of the synapomorph characters shared by Serranochromis and Sargochromis alone. Inthe absence of these characters from '//.' darlingi, and because an enlarged pharyngeal mill hasapparently evolved independently in several haplochromine lineages, I consider that the affinitiesbetween this species and Serranochromis (including Sargochromis} are not as close as those im-plicit in Trewavas' proposed ancestor-descendant relationship. In my view, Serranochromis and Sargochromis shared a recent common ancestry not sharedwith '//.' darlingi (the common ancestor for the former taxa could well have resembled S. (So)greenwoodi in its anatomical, morphological and meristic features; see description in Bell-Cross,1975). Any relationship between the genus Serranochromis and '//.' darlingi would be at a more distantlevel because these two taxa share fewer derived features than do Serranochromis andSargochromis. Finally, comment must be made on the superficially close resemblance between members ofthe subgenus Serranochromis (Serranochromis} and certain 'Haplochromis' species of Lake Vic-toria (the spekii-serranus species complex, see Greenwood, 1967 : 109, and 19740 : 80 et seq. ; alsoTrewavas, 1964 : 6). That the resemblance is the result of convergent evolutionary trends towardsthe production of an adaptive morphotype (piscivorous predator) and not one of close phyleticrelationship seems evident from the several features in which the two taxa differ from one another.For example, the predominantly cycloid and weakly ctenoid scales of Serranochromis comparedwith the strongly ctenoid scales of the 'Haplochromis' species, the few and fully ocellate egg-dummies of the latter as contrasted with the numerous, small and non-ocellate anal spots inSerranochromis, and the more numerous gill rakers, branched fin rays and, particularly, the highnumber of abdominal vertebrae in the latter taxon. Certainly it would seem more parsimonious to suppose that Serranochromis and the LakeVictoria Haplochromis were derived from different lineages, rather than to suggest a commonancestry from some widespread lineage of fluviatile, piscivorous predators (an idea I had enter-tained previously when considering the phyletic history of the Lake Victoria species flock). It would seem possible, too, that there is no close phyletic relationship between Serranochromisand certain ' Haplochromis' species in Lake Malawi (see Trewavas, 1964 : 6), but more research isrequired on the Malwai species before this idea can be tested adequately. CHETIA Trewavas, 1961. TYPE SPECIES. Chetia flaviventris Trewavas, 1961 (Holotype and paratypes in the BMNH, 3 para-types in the Transvaal Museum, Pretoria). NOTE. The species Chetia brevis Jubb, 1968 is excluded from this genus because in adult malesthe anal fin markings are large, true ocelli and few in number (3 or 4). Also, unequally bicuspidouter jaw teeth are still present in specimens of a size (86-89 mm SL) when, in Chetia flaviventris,the outer row is comprised mainly of unicuspid and caniniform teeth ; the few bicuspid teethpresent in C. flaviventris of that size are different from those in C. brevis since the minor 'cusp'is a shoulder and not a point. Description The body form is moderately slender (depth of body 29-35 % of standard length). Squamation. The scales on the head, chest, cheek and body above the upper lateral line arecycloid, and cycloid scales predominate on the body below that level as well; a few weaklyctenoid scales may be present anteriorly on the body, the ctenii on these scales being confined toa short median arc on the scale's free margin. It seems possible that a higher proportion ofctenoid scales is present in smaller than in larger individuals; the largest specimen examined hasonly cycloid scales on all parts of the body and head (see also Trewavas, 1961). The cheek is completely scaled (5 or 6 horizontal rows}. The chest scales show a gentle sizegradation with those on the belly and ventrolateral aspects of the flanks. 308 P. H. GREENWOOD There are 34 or 35 scales in the lateral line series, with only the last one or two pore-bearingscales of the upper lateral line separated from the dorsal fin base by less than two scales of almostequal size. Neurocranium. The skull has a moderately produced preotic region (c. 68-70 % of total neuro-cranial length). The ethmovomerine region is not noticeably extended, and slopes at a slightangle. In its proportions and general shape, the neurocranium in Chetia approaches that in thesubgenus Serranochromis (Serranochromis), but has a less elongate ethmovomerine region. Vertebral numbers and apophysis for the dorsal retractor muscles of the upper pharyngealbones. There are 30-32 (mode 31) vertebrae, comprising 14 or 15 (mode 15) abdominal and15-17 (modes 16 and 17) caudal elements. Trewavas (1961) reports an absence of any bony apophysis for the origin of the pharyngealmuscles; from the radiographs I have examined (i.e. of the holo- and 4 paratypes) the structureis visible in one specimen. Trewavas (1961) implies that the apophysis serves principally for theattachment of the swimbladder. That organ certainly is attached to the posterior face of theapophysis in all cichlids I have examined, but the greater surface area of the apophysis serves asa point of origin for the pharyngeal retractor muscles. Dentition. Unicuspid teeth predominate (or are the only kind of teeth present) in specimens morethan 30 mm standard length; the few bicuspid teeth present have a much reduced, shoulder-like minorcusp, and are mostly replaced by unicuspids in specimens > 35 mm S.L. There is, however, a sizecorrelated change in the kind of unicuspid teeth present. Fishes < 35 mm long have ratherflattened, almost spear-shaped unicuspids whereas in larger fishes the teeth are caniniform. Unicuspid teeth also predominate in the inner rows of fishes at all sizes, although a few weaklybicuspid teeth are present in specimens less than 40 mm SL. There are one, or, less commonly, tworows of inner teeth anteriorly in both jaws, and a single series laterally. Lower and upper jaws. The lower jaw has the appearance and proportions of that in Serrano-chromis (Serranochromis) species, but in the upper jaw the ascending premaxillary process doesnot reach to between the orbits as it does in many of the latter species ; it reaches only to aboutthe midpoint of the anterior orbital margin. Lower pharyngeal bone and teeth. The bone is not thickened, has an almost equilateral denti-gerous surface, and its teeth are slender and weakly cuspidate (Fig. 19). Those teeth forming thetwo median rows and the posterior transverse row are slightly coarser than their congeners. Dorsal fin with 14 or 15 spinous and 11 or 12 branched rays. Anal fin with 3 spines and 9 or 10 branched rays. Caudal fin skeleton. All the hypurals are free in the five specimens radiographed (the typeseries). Caudal fin is subtruncate. Pelvic fin has the first branched ray the longest. Anal fin markings in male fishes. As in Serranochromis (see p. 302) there are numerous, smalland non-ocellate spots covering a large area of the soft anal fin, the spots resembling in size andcoloration those on the soft part of the dorsal fin. According to Du Plessis & Groenewald (1953) the anal spots in C.flaviventris are more plentifulin males than in females, and the species is a female mouthbrooder. Gill rakers are moderately short and slender, with 9 or 10 rakers in the outer row on the lowerpart of the first gill arch. Contained species Chetia flaviventris Trewavas, 1961 (Type species). Tributaries of the Limpopo and Incomati rivers, Transvaal, South Africa. Diagnosis and discussion The single species in this genus is distinguished from the other fluviatile ' Haplochromis' -groupspecies, except Serranochromis, by the nature of the anal fin markings in adult males, which arenumerous, small and non-ocellate (and which barely differ from those in females). In addition,Chetia is distinguished from Ctenochromis, Orthochromis and Thoracochromis by the nature of A REVISION OF THE HAPLOCHROMIS GENERIC CONCEPT 309 the scale pattern in the thoracic-abdominal region (a gradual as compared with an abrupt sizechange in the scales of the two body regions). From Serranochromis, Chetia is distinguished mainly by having fewer (14 or 15) abdominalvertebrae (cf. 16-18, rarely 15, in Serranochromis) and by having bicuspid teeth in specimens ofa larger size. In meristic characters, other than vertebral numbers, the two genera have a com-parable overlap, but for each feature the modal values are distinct, those for Serranochromisbeing the higher. B 3mm Fig. 19 Lower pharyngeal bone of Chetia flaviventris. A. Occlusal view.B. Right lateral view (bone aligned vertically). I can detect no apomorph features which would suggest that Chetia might be related to anyof the three lineages showing an abrupt size change in the thoracic-abdominal squamation, andnor can I find apomorph characters to associate it with Haplochromis, Astatotilapia or Astatoreo-chromis . That Chetia and Serranochromis share a similar kind of anal fin marking does not necessarilyimply a close relationship between them either, since it seems likely that this is a primitive(plesimorph) feature for 'Haplochromis' -group species (see above, p. 275). I can detect no unequi-vocally synapomorphic features common to Chetia and Serranochromis and thus, despite theirsuperficial similarities, cannot place the taxa in the same genus. Likewise, the almost identical anal fin markings in Chetia and 'Haplochromis'' darlingi (seebelow, p. 310) cannot be taken to indicate a close relationship. It is for this reason, as well as theirlack of uniquely shared apomorph features and the presence of autapomorph features in eachspecies, that has led me to place Chetia flaviventris and '//.' darlingi in separate lineages, and thusto give the latter taxon generic rank (see p. 312). Trewavas (1964 : 10) has remarked on the similarity between Chetia and certain Serranochromisspecies, a similarity which led her to consider Chetia an offshoot from a lineage that also containsS. (Serranochromis) thumbergi and S. (S.) robustus. That there are similarities between the threespecies is undeniable, but Chetia does not share with the two Serranochromis species (and withother species of the genus) the derived feature of a high number of abdominal vertebrae. It does,of course, share with all Serranochromis (Serranochromis) species the early ontogenetic appearanceof unicuspid outer and inner jaw teeth (see p. 300), an apomorph feature which Serranochromis(Sargochromis) does not share with the nominate subgenus. 310 P. H. GREENWOOD Thus at present, one cannot find a totality of shared apomorph features which would indicatea clear-cut sister group relationship for Chetia. For that reason I would consider that Chetia isbest represented as a monotypic lineage (genus) of uncertain affinities. Intuitively one suspectsthat Chetia is related either to Serranochromis (especially the nominate subgenus of that taxon)or to ' Haptochromis* darlingi. But, the evidence to propose formally one or other of these relation-ships is not available if the classification adopted is to reflect phyletic relationships. Superficially, Chetia also resembles one of the Angolan 'Haphchromis' species, '//.' welwitschiiBlgr., a taxon known only from its now poorly preserved holotype. Until more and better docu-mented material of the Angolan 'Haplochromis' is available for study, any possible relationshipbetween Chetia flaviventris and '//.' welwitschii cannot be investigated (see also p. 312 below). PHARYNGOCHROMIS gen. nov.TYPE SPECIES. Pelmatochromis darlingi Blgr., 1911. (Holotype in the BMNH collections.) SYNONYMY. See Regan (1922a). Description Body form moderately slender (body depth 30-33 % of standard length). Squamation. The body squamation type and pattern is like that in Chetia (see p. 307). Thecheek is fully covered by 4 or 5 horizontal scale rows. There are 32-34 (modes 32 and 33), rarely31, scales in the lateral line. Neurocranium. The preotic portion of the skull is slightly less protracted that in Chetia, thebrain case is a little higher and the slope of the dorsal skull profile a little steeper. In other words,the overall skull morphology is somewhat more like that in Serranochromis (Sargochromis)species than in Chetia, a resemblance that may be associated functionally with the enlargedpharyngeal bones and dentition present in both taxa. Vertebral numbers: 29 or 30 (mode 29), comprising 13 or 14 (mode 14) abdominal and 15 or16 (mode 15) caudal elements. An apophysis for the dorsal retractor pharyngeal muscles ispresent on the third centrum. Dentition. There is a predominance of unicuspid, caniniform teeth in the outer row of bothjaws in fishes over 60 mm standard length, but even in the largest specimens examined (90 mm SL)many unequally bicuspid teeth persist (and, occasionally, may be the predominant form). Uni-cuspids also predominate in the inner tooth rows, the other teeth being bi- or weakly bicuspid. The inner rows of both jaws are arranged in two series anteromedially and a single row laterallyand posteriorly. Jaws. The lower jaw is somewhat shorter and deeper than in Chetia, but the premaxilla issimilar in both genera. Lower pharyngeal bone and dentition. The dentigerous surface is equilateral or almost so, andthe bone itself is somewhat thickened medially (noticeably so when compared with that in Chetia).The two median tooth rows are composed of coarse, stout and molariform or submolariformteeth (Fig. 20), the latter retaining traces of a small, near-central point on the occlusal surface.The teeth in the row, or the two rows on either side of the median series, are markedly coarserthan those in the lateral rows (which are also clearly cuspidate), and may have submolariformcrowns. Dorsal fin with 14 or 15 (mode 14), rarely 13, spines and 10-12 (mode 1 1) branched rays. Anal fin with 3 spines and 7-8 branched rays. Caudal fin skeleton. All hypurals are free in the 4 specimens (including the holotype)radiographed. Caudal fin: strongly truncate to virtually rounded. Pelvic fin: with the first branched ray the longest. Anal fin markings in male fishes. As in Chetia and Serranochromis, there are numerous (up to18, according to Bell-Cross, 1976), small orange spots on the soft part of the fin, and sometimesextending onto the membrane between the spines as well. Pharyngochromis darlingi is a female A REVISION OF THE HAPLOCHROMIS GENERIC CONCEPT 311 mouthbrooder (Bell-Cross, 1976). For coloured illustrations see Jubb (\961a : pi. 46); Bell-Cross(1976 : pi. 16). Gill rakers are short and stout, with 9 or 10 (less commonly 7 or 8) in the outer row on thelower part of the first gill arch. Contained species Pharyngochromis darlingi (Blgr.), 1911. Type species. Widely distributed in the Zambesi river system and southwards to the Limpopo. 3mm Fig. 20 Lower pharyngeal bone of Pharyngochromis darlingi. A. Occlusal view.B. Right lateral view (bone aligned vertically). Poll (1967) recorded this species (as Haplochromis darlingi) from Lake Calundo (Zambesidrainage), Angola, and also redetermined, as H. darlingi, specimens from the Cubango riverwhich Pellegrin (1936) had identified as Haplochromis welwitschii. However, judging from thenature of the anal fin markings in male specimens, I suspect that these specimens should not bereferred to P. darlingi. Their identity should be more firmly established (possibly as a yet un-described species) when a thorough revision of the Angolan 'Haplochromis' species is carried out(see p. 312). The same features distinguishing Chetia from the other fluviatile 'Haplochromis' -group genera,including Serranochromis, also serve to distinguish Pharyngochromis. From Chetia itself, Pharyngochromis is distinguished, chiefly, by its stouter lower pharyngealbone and its partly molarized dentition, by having lower modal numbers of abdominal andcaudal vertebrae, fewer lateral line scales, and by having a larger proportion of bicuspid teethin the outer tooth row of both jaws in fishes more than 40 mm standard length. My reason for not treating Chetia flaviventris and Pharyngochromis darlingi as members of thesame genus is their lack of shared derived features (see above, p. 310). The same reasons led meto exclude Pharyngochromis from the Sargochromis division of the Serrano chromis lineage. Presumably it is the presence of enlarged pharyngeal teeth, as well as overall similarity in bodyform and oral dentition, that led Trewavas (1964 : fig. 1 and p. 9) to place P. darlingi at the baseof a lineage leading to Sargochromis (then restricted to the type species, S. codringtoni). Deriva-tives from, and members of, this lineage also included a number of Zambesi 'Haplochromis'species which I now place in Sargochromis. 312 P. H. GREENWOOD Since the subgenera Serranochromis and Sargochromis share certain derived features (especiallyan increased number of abdominal vertebrae) not found in Pharyngochromis it would seem moreparsimonious to consider that the two former taxa share a recent common ancestry and that anyrelationship they may have with Pharyngochromis is a more distant one. The alternative classification implicit in Trewavas' (1964) phyletic diagram, that Chetia andSerranochromis (i.e. my subgenus Serranochromis (Serranochromis)) are sister-groups, and thatSargochromis (i.e. my subgenus Serranochromis (Sargochromis)) plus Pharyngochromis is thesister-group of Chetia and Serranochromis combined, is not supported by the distribution ofderived characters amongst the taxa involved. Such an arrangement would also imply that thederived features shared by Sargochromis and Serranochromis were evolved independently. Ad-mittedly in my scheme one specialized feature (the enlarged pharyngeal bones and dentition ofPharyngochromis and most Sargochromis species) would have to be evolved independently. But,evidence from haplochromine lineages in Lake Victoria (see Greenwood, 1974a) and fromThoracochromis (e.g. Th. mahagiensis and Th. pharyngalis) seems to indicate that the independentevolution of an enlarged pharyngeal mill is not uncommon amongst ' Haplochromis '-groupcichlids. To summarize: the relationships amongst those l Haplochromis' -group taxa with non-ocellateand numerous anal fin spots (a group essentially of the Zambesi, Limpopo, and Angolan rivers)cannot clearly be recognized at present. Two lineages with a presumed recent common ancestry(Serranochromis and Sargochromis) are treated as sister-groups and given subgeneric rank; theother two lineages cannot be related unequivocally (on the basis of shared derived characters)with either the Serranochromis-Sargochromis lineages or with one another; each therefore istreated as a monotypic and monophyletic assemblage (on the basis of autapomorphic features)and given generic rank (Chetia and Pharyngochromis). The further resolution of relationships amongst these taxa awaits more detailed studies of theircontained species (and of the Angolan ' 'Haplochromis' species), and an understanding of thephyletic importance which can be attached to anal fin markings. The Angolan ^Haplochromis^ species Several references have been made to these little-known and poorly represented taxa. The lastcomprehensive revision of the Angolan Haplochromis was that of Regan (19220) who recognizedthree species, H. humilis (Steindachner), 1866, H. acuticeps (Steindachner) 1866 and H. multi-ocellatus (Blgr.) 1913. For some reason not stated (but probably because Boulenger (191 5) includedboth species in Pelmatochromis), Regan omitted Steindachner's (1865) Hemichromis angolensisand Boulenger's (1898) Pelmatochromis welwitschii. Both species, however, would have fallen intoRegan's definition of Haplochromis. All the specimens representing these species (and others synonymized therein by Regan,19220) are poorly preserved, mostly represented by a single individual (or at best 4 or 5 syntypes),and often without precise locality data ; the type of P. angolensis is now lost (see Bell-Cross,1975 : 427). In recent years Poll (1967) has added three species (H. thy si, H. machadoi and H. schwetzi;see pp. 305 and 297 above for the first two species respectively), Trewavas and Thys van denAudenaerde (1964) a fourth (H. albolabris) and Penrith (1970) a fifth (H. buysi). My revision of this material indicates that probably several lineages are represented within it,and that Regan's (1922) re-definition of H. acuticeps (Steindachner) embraces at least twospecies. Some of the Angolan species seem to show affinity with the genus Astatotilapia, otherswith Chetia and some may represent lineages yet unrecognized. But, until the species can berevised and reviewed on the basis of more extensive, better preserved and better documentedcollections I believe that it is inadvisable to place any species in the genera recognized in thispaper. It is certainly impossible to demonstrate that the Angolan species are more closely relatedto one another than to any other lineage, although intuitively one recognizes, in at least somespecies, an 'Angolan fades' and feels that this overall appearance suggests relationships with theZambesi-Limpopo genera. A REVISION OF THE HAPLOCHROMIS GENERIC CONCEPT 313 Trewavas' (1964) phyletic diagram illustrating the possible relationships of ''Serranochromis'and 'Sargochromis' indicates that a number of Angolan ' Haplochromis' species are related to'Serranochromis' (i.e. the subgenus Serranochromis (Serranochromis) as defined on p. 299). I canfind no synapomorph characters to support this supposition. The very faint traces of anal finmarkings left on the holotype of H. welwitschii suggest that they may be of the Serranchromis-Chetia-Pharyngochromis pattern but this is probably a plesiomorph feature. Where anal finmarkings are detectable in the other species mentioned by Trewavas (1964), for exampleH. lucullae, they appear to be of the true ocellar type and thus a derived feature not representedin Serranochromis. The number of vertebrae (especially the abdominal elements) in H. welwitschii and the otherAngolan species is lower than that in Serranochromis (although within the range for Chetia) andagain represents a plesiomorph condition. Other characters and character states are equally lacking in shared apomorph features, orrepresent autapomorphies characterizing the Angolan taxa alone. As a temporary expedient I can only suggest that the Angolan species be given no formalgeneric status and that they should be referred to under the informal epithet ' 'Haplochromis',whose use in no way implies a close relationship with the species of Haplochromis (or, indeed,the majority of species previously referred to that genus). Summary and conclusions I am well aware of the shortcomings in this preliminary attempt to clarify the phylogeneticrelationships of 'Haplochromis' -group cichlids, and in particular members of that manifestlypolyphyletic 'genus' Haplochromis. Two major difficulties were encountered, and although one has been overcome to a greater orlesser degree, the other still stands in the way of a fully phylogenetic classification. The firstdifficulty lies in determining morphocline polarity amongst the characters available for researchof this kind (p. 270). Then, when plesiomorph and apomorph features are recognized, there is theproblem caused by an apparent absence of synapomorphic features at the various levels ofrelationship necessary to construct a truly cladistic classification. In other words, one can identify fairly readily what appear to be monophyletic lineages, butthe difficulties arise when one attempts to interrelate the different lineages on a sister-group basis. The problem is well exemplified by the genera Ctenochromis, Thoracochromis and Orthochromis.All three taxa share the presumably derived feature of an abrupt size-change between the scaleson the thoracic and ventrolateral flank regions of the body (see p. 270), and thus are assumed toshare, at some level, a common ancestry. Both Orthochromis and Ctenochromis, but not Thoraco-chromis exhibit derived features that are unique for each genus (i.e. autapomorphies) but thereare no synapomorphic characters that would indicate which two of the three genera are moreclosely related to one another. Since Thoracochromis shows only one apomorph feature commonto all its species it is, presumably, the least derived member of the trio. Similar difficulties arise with Haplochromis, Astatotilapia and Astatoreochromis, taxa whichappear to be interrelated (along with the components of the Victoria-Edward-Kivu speciesflock) only on the basis of their possessing true ocellar spots on the anal fin of male fishes (p. 274).Haplochromis and Astatoreochromis (and each of the major lineages in the Victoria flock) haveclear-cut autapomorphic features; Astatotilapia, apparently, has none. Again one is left with anunresolved polychotomy, but in this case, because the lake flocks are involved, a far more com-plex one. Finally, but in a rather different category, since no unifying synapomorphic characters havebeen detected, are the genera Chetia, Pharyngochromis and Serranochromis. Intuitively the taxawould seem to be interrelated (as they have been assumed to be by other workers, e.g. Trewavas,1964), probably because of their similar overall morphology, coloration, and the repeatedoccurrence of enlarged pharyngeal mills amongst their constituent species; in addition, thespecies form a well-defined, Zambesian geographical group. Yet, I have failed to substantiatetheir presumed relationship because there are no apparently derived features common to all three 314 P. H. GREENWOOD genera (see p. 312). Of course, my interpretation of one shared feature (the non-ocellate, and verynumerous anal spots) as a primitive condition may be incorrect (see p. 275); only further research,especially comparative ethological research, can clarify that point. Further research is also needed to test the phylogenetic homogeneity of the speciose lineageThoracochromis (see above and p. 294). As yet no way has been found to test the possibility,indicated by certain morphological features, that there are three infragroups represented in thelineage, viz. one in Lake Turkana, another in the Nile and Lake Albert (including also the outlierspecies from Lake Edward and possibly Lake Victoria), and a third from the Zaire river system. Despite these limitations I believe that the classification suggested here is a more efficient onethan that existing at present (the term 'efficient' used sensu Patterson & Rosen (1977 : 158-159)to denote a classification from which a '. . . theory of relationships is recoverable . . . withoutloss of information'). Clearly its efficiency can be improved, but that must await the phyleticanalysis of ' Haplochromis '-group species in the Great Lakes, especially those of Lakes Malawiand Victoria. It has been generally assumed (see Regan 19216; Trewavas, 1935; Fryer & lies, 1972) that theMalawi 'Haplochromis' -group species were derived from an anatomically generalized fluviatile' Haplochromis' (i.e. Astatotilapia) species. I now suspect, however, that the story is far morecomplex, that the Malawi flock is probably of polyphyletic origin and that lineages related toThoracochromis as well as to Astatotilapia and even to Serranochromis and Chetia may havecontributed to the flock. Possibly some of the ideas put forward in this paper may contribute tothe elucidation of that problem. Likewise the assumed monophyly of the Lake Victoria ' Haplochromis' species flock (Green-wood, 1974a) must be thrown into doubt, because no characters have been found to support thisconcept (see p. 269). As compared with Lake Malawi, however, it does seem more likely thatfewer and phyletically more closely related lineages were involved, and that most are related tothe Astatotilapia lineage. Geographically, the different lineages dealt with in this paper have interesting patterns ofdistribution. Thoracochromis is essentially a Nilotic-Zairean taxon (see p. 294). Unlike the others withZairean representatives (see below), it is best represented in the lower reaches of that river, sinceonly one species (Th. moeruensis) is recorded from the upper Zaire system (see p. 293). The virtual absence of Thoracochromis from Lakes Victoria, Edward and Kivu is, on thebasis of its overall distribution, rather surprising. Possibly this is attributable to the relativelyrecent association between these lakes and the Nile system (see Beadle, 1974 : 139-146; Green-wood, 19746 and 1976; Berry, 1976; Livingstone, 1976; Rzoska, 1976a & b : 2-29). Lake Turkanaand, as far as can be told, Lake Albert as well, have only ever had major and direct intercon-nections with the Nile system; the geologically recent riverine connection between Lakes Albertand Victoria probably is made impassable to fishes by the presence of the Murchison Falls (nowKabalega Falls), and the connection between Lakes Edward and Albert via the Semliki riveralso seems to be impassable for most fishes (see discussions in Greenwood, 19596, 1973 and1976; also Rzoska, 1976c : 197-202). Astatotilapia, apart from its outliers in North Africa (A. desfontainesi), Syria and Israel(A. flaviijosephi) and possibly in Nigeria (see p. 283), is essentially a lineage of the eastern RiftValley (except Lake Turkana) and the rivers of eastern Africa; it is represented in the Zairedrainage only by its species in Lake Tanganyika (see p. 284). The absence of Astatotilapia fromLake Turkana probably is to be explained through the history of that lake (see above). Far morepuzzling is the occurrence of two Astatotilapia species north of the Sahara (Tunisia, Algeria,Syria and Israel), and the possibility of one or two other species in Nigeria. This disjunct distri-bution may, of course, be the result of incorrectly assessing the phyletic relationships of theoutlier species. On currently available evidence, however, there is nothing to suggest how elsethese outlier species might be interrelated. Ctenochromis, with one exceptional species (C. pectoralis) from southeastern Tanzania (IndianOcean drainage), is totally Zairean (including Lake Tanganyika) in its distribution (see p. 289).Orthochromis too is an essentially Zairean lineage and, like Ctenochromis, is confined to the upper A REVISION OF THE HAPLOCHROMIS GENERIC CONCEPT 315 parts of that system; it has a representative in the Malagarasi river system of Tanzania, buthistorically that river should be considered part of the upper Zaire drainage (Poll, 1956). Theonly outlier species, Orthochromis machadoi, occurs in the Cunene river, Angola, a river whoseichthyofaunal affinities are closer to those of the Zambesi than the Zaire (Poll, 1967). Serranochromis is widely distributed (see p. 302), having representatives in the Zaire and Zam-besi systems, as well as in the Limpopo and certain Angolan rivers (including the Cunene). Bothits Zairean and Zambesi components are confined to the upper portions of their respectivesystems (cf. the distribution of Thoracochromis). Chetia and Pharyngochromis have, geographically speaking, the most restricted distributionsof all the fluviatile species considered in this paper (apart from Astatoreochromis which occursonly in parts of the Malagarasi and Lukuga rivers, in Lakes Edward and Victoria and in somephysiographically related water bodies, see p. 286). Chetia, a monotypic genus, is confined to theLimpopo drainage system, and Pharyngochromis, also monotypic, to the Upper and MiddleZambesi, the Sabi-Lundi system and the Limpopo system. The only truly lacustrine lineage discussed in this paper, Haplochromis, is confined to LakesVictoria, Edward, George and Kivu. The significance of this distribution, and the possiblerelationships of the genus, will be discussed in a forthcoming revision of the lineages from thoselakes. Key to the genera Notes (i) When citing the range for meristic characters, values rarely encountered are given insquare brackets and precede or follow, respectively, the most frequently recorded low and highvalues for that character. (ii) Modal values (or modal ranges) are in bold type and enclosed in round brackets. (iii) Gill raker counts are for the outer row of rakers on the lower part of the arch, and do notinclude the raker (if such is present) on the epi-ceratobranchial articulation. (iv) For further notes, and definitions of the characters used see pp. 270-276. Key A gradual change in size between the scales on the chest (i.e. ventral and ventrolateral body regionanterior to the insertions of the pectoral and pelvic fin bases) and those on the ventral andventrolateral aspects of the flanks and belly (see Fig. 1) ....... 1 An abrupt size change between the small scales on the chest and the larger scales on the ventro-lateral and ventral aspects of the body, the size demarcation line usually running between thepectoral and pelvic bases (but sometimes a little before or behind that level; seeFigs 2, 3 & 9) 2 (p. 316) 1) (a) Anal fin in adult males with 3-9 (3 or 4) ocelli (coloured spots each with a clear or trans-lucent area surrounding it) arranged in one or two lines and lying about midway betweenthe base and the distal margin of that fin. (Most females and juvenile males with 3 or 4non-ocellate spots in the same position, or fin without spots.) Scales below (and oftenthose above) the upper lateral line ctenoid, the ctenii arranged along almost the entirefree margin of the scale. Anal fin with 3 spines (individuals with 4 spines are so rare thatthis number can be considered as an individual abnormality). Dorsal fin rarely withmore than 16 spines. Marked sexual dimorphism in adult coloration (males colorful,females drab) ............. A (b) Anal fin in adult males with 6-20 ocelli arranged in 3-5 regular rows and thus occupying a large area on the soft part of the fin; females with a similar pattern if spots (non-ocellate) are present. Anal fin with 3-6 spines, dorsal fin with 16-20 (17-19) spines. Cau-dal fin rounded. Lower pharyngeal bone thickened (strongly so in two species), itsdentition partially or completely molarized. No marked sexual dimorphism in colora-tion; body colour yellow-green, fins with a maroon flush. Other features as in l(a) above Astatoreochromis (p. 285) (c) Anal fin in both sexes with numerous (18-40) small spots, none with a clear or translucent surround, not arranged in regular rows but covering most of the area of the soft anal fin;similar spots on the soft dorsal and the caudal fins. Scales below the upper lateral lineare cycloid or predominantly cycloid; when ctenoid scales are present the ctenii are weakand confined to a small median sector on the free margin of the scale. . . . B 316 P. H. GREENWOOD A)(i) Jaw teeth in the outer row (and sometimes the inner rows as well) with obliquely cuspidate compressed crowns, the major cusp drawn out beyond the tooth's verticalaxis (see Fig. 7), the minor cusp reduced or absent. 12-14 (13) abdominal and 15or 16 caudal vertebrae (total 28-30; 28 and 29). Dorsal fin with 14-16 (15 and 16)spines and 8-10 (9) branched rays. Anal fin with 3 spines and 7-10 (9) branchedrays. Lateral line with 29-34 (30-32) scales. Cheek with 3 [4] horizontal rows ofscales. Caudal fin truncate or weakly subtruncate. Lower pharyngeal bone withoutany noticeably enlarged or coarse teeth in the two median rows. Gill rakers [7] 8-10(9) '.".."'. Haplochromis(p.218) (ii) Jaw teeth in the outer row unequally bicuspid or unicuspid, the crown neither com-pressed nor obliquely truncate, its tip lying within the tooth's vertical axis (seeFig. 4). Outer teeth mostly bicuspids in fishes <70 mm SL; an admixture of bi- andunicuspids in larger fishes, with unicuspids predominating in specimens > 100 mmSL. Inner teeth predominantly tricuspid, small. 12-14 (13) abdominal and 14-16(15) caudal vertebrae (total 27-30; 28 and 29). Dorsal fin with 14-16 (15) spines and8-11 (9 and 10) branched rays. Lateral line with 28-30 (in one species 31-34)scales, cheek with [2], 3, [4] horizontal rows of scales. Caudal fin rounded or slightlysubtruncate. Lower pharyngeal bone with at least the two median rows composedof coarser (sometimes molariform) teeth. Gill rakers [7] 8 or 9 . Astatotilapia (p. 281) B) (i) Abdominal vertebrae 13 or 14 (14), caudal vertebrae 15 or 16 (15), total number ofvertebrae 29 or 30 (29). Dorsal fin with 14 or 15 (14) spines and 10-12 (11) branchedrays. Lateral line with 32-34 (32 and 33) scales, cheek with 4 or 5 horizontal rows.Outer row of jaw teeth composed of unequally bicuspids in fishes <60 mm SL,unicuspids present and becoming commoner in larger individuals. Lower pharyn-geal bone thickened, at least the two median rows composed of enlarged andmolariform teeth (see Fig. 20). Gill rakers [7 or 8] 9 or 10. Anal fin with up to 20spots .......... Pharyngochromis (p. 310) (ii) Abdominal vertebrae 14 or 15, caudal 15-17 (16 and 17), total number of vertebrae30-32 (31). Dorsal fin with 14 or 15 spines and 11 or 12 branched rays. Lateral linewith 34 or 35 scales, cheek with 5 or 6 horizontal rows of scales. Outer row of jawteeth mainly unicuspids in fishes >30mm SL, some weakly bicuspids (the minorcusp a shoulder rather than a point) present in smaller individuals. Lower pharyn-geal bone not thickened, without molariform or submolariform teeth (see Fig. 19).Gill rakers 9 or 10 Chetia (p. 307) (iii) Abdominal vertebrae [15] 16-18 [19] (16 and 17), caudal vertebrae 12-16 (14 and 15),total number of vertebrae 28-32 (31). Dorsal fin with 13-16 (15 and 16) spines and1 1-16 (12 and 13) branched rays. Lateral line with 28-34 (30 and 31) scales, cheekwith 3-6 (3 - 5) horizontal rows of scales. Outer jaw teeth mostly unequally bicus-pids in fishes <150 mm SL, predominantly unicuspids in larger individuals. Lowerpharyngeal bone thickened in all but one species, and in all but that species with atleast the two median tooth rows composed of enlarged and molariform teeth (seeFig. 18); the exceptional species has coarse and slightly enlarged, but cuspidate,teeth in the median rows (see Fig. 18A), Gill rakers 9-15 (12 and 13). Anal fin withup to 40 spots. ...... Serranochronris (Sargochromis); p. 303) (iv) Abdominal vertebrae [15] 16-18 [19] (16 and 17), caudal vertebrae [15] 16-18 (16 and17), total number of vertebrae 31-36. Dorsal fin with 13-18 (15 and 16) spines and13-16 (14-16) branched rays. Lateral line with [34] 35-41 scales, cheek with 3-11(5-9) horizontal rows of scales. Outer jaw teeth predominantly or entirely unicus-pids in fishes > 30 mm SL. Lower pharyngeal bone not thickened, either elongateand narrow (see Fig. 14A & B) or its dentigerous surface almost equilateral inoutline (see Fig. 14C); no teeth molariform, even the median row teeth only slightlycoarser than the others. Gill rakers [8] 9-13 (10-12). Anal fin with up to 40 spots Serranochromis (Serrunochromis) ; p. 299) 2) (a) Pelvic fin with the first branched ray the longest. Scales on ventral body surface behind pelvic fins not markedly reduced in size (see Fig. 9) ...... 2A (b) Pelvic fin with the second or third branched ray the longest. Scales on ventral body surfaceand on ventrolateral aspects of flanks small to minute (see Fig. 3). Cheek naked or, ifscaled, with a definite naked area along its entire ventral (preopercular) margin. Chest A REVISION OF THE HAPLOCHROM1S GENERIC CONCEPT 317 completely scaled, or partly scaled, or naked. Dorsal fin with 16-20 (17 and 18) spinesand 9-11 (9 or 10) branched rays. Anal fin with 3 or 4 spines and 7-10 branched rays.Lateral line with 30-35 (30 and 31) scales. Head profile strongly decurved, eyes supro-lateral in most species ......... Orthochromis (p. 295) 2A) (i) Chest with a naked patch or extensive naked area on each side of the body (see Fig. 9).At least the ventral part of the cheek scaleless (almost the entire cheek naked in onespecies). Anal fin with 3 spines and 6-9 (6-8) branched rays. Lateral line with 27-33 (28 and 30 or 31) scales Ctenochrotnis (p. 287) (ii) Chest completely scaled. Cheek completely or almost completely scaled (i.e. onehorizontal row absent ventrally). Dorsal fin with 13-16 [17] (14-16) spines and8-10 [11] (9 and 10) branched rays. Anal fin with 3 spines and 6-10 (7-9) branchedrays. Lateral line with 29-32 (30-32) scales . . . Thoracochromis (p. 290) Appendix 1 A replacement 'generic' name for the Lake Malawi ^ Haplochromis'' species Since the genus Haplochromis is now restricted to five species, all members of the Lakes Victoria,Edward, George and Kivu species flock (p. 280), the Lake Malawi species formerly referred toHaplochromis are without a generic name. Because it is obvious that the 'Haplochromis' of LakeMalawi are a polyphyletic group, any generic placement at the present time must be consideredmerely a formal nomeclatural action unrelated to the phyletic affinities of the species. Two generic names would appear to be available for this purpose (see Trewavas, 1935), namelyCyrtocara Boulenger (1902) and Champsochromis Boulenger (1915). A third name, Otopharynx,Regan (1920), apparently is also available, but it is junior to the others and there are anatomicalgrounds for regarding its contained species as representing a lineage distinct from that to whichmany Malawi 'Haplochromis'' belong (Greenwood, 1978). Cyrtocara (type species C. moori) has a pharyngeal apophysis of the typical 'Haplochromis'-type(Trewavas, 1935) and its oral dentition is composed of slender unicuspid outer teeth and mixeduni- and tricuspid inner teeth. Although at least some members of the type species have a moderately developed hump in thefrontal region of the head, I can see no morphological grounds for not accepting Cyrtocara as atemporary formal name for the ' Haplochromis' species of Lake Malawi. I thus propose that it beused in that capacity until the Malawi species are revised. This action by no means implies thatI consider many of these species to have a true phyletic relationship with Cyrtocara moori. Appendix 2 The taxonomic status of the genus Limnotilapia Regan, 1920 In a recent paper (Greenwood, 1978) I treated the genus Limnotilapia Regan (1920) as a synonymof Simochromis Boulenger, 1898, thus unintentionally anticipating the publication of a papergiving detailed reasons for this nomenclatural change. Since publication of the paper in whichthe two 'genera' are to be discussed is likely to be delayed further, the reasons for synonymizingLimnotilapia with Simochromis are dealt with below. A comparison of Regan's (1920) description for Limnotilapia with his redescription of Simo-chromis reveals that the taxa apparently are differentiable only on the former having a rathersmall, terminal mouth, and the latter having the mouth subterminal and rather wide. When the type species of the genera, Limnotilapia dardennii (Blgr.) and Simochromis diagramma(Giinth.), are compared, these differences can be translated into more substantial osteologicalones involving the morphology of the premaxilla and dentary. Viewed from below (i.e. occlusally), the premaxillary outline in L. dardennii is gently curvedand relatively narrow; in other words, it has an outline approximating to that of a Norman arch.The premaxillary outline in S. diagramma, by contrast, has a virtually straight and wide anteriormargin, with the short posterior dentigerous arms meeting it almost at right angles; the outline 318 P. H. GREENWOOD of the bone is thus more nearly that of a hollow square. The posterior dentigerous arms of thepremaxilla in 5 1 . diagramma are slightly bullate, whereas in L. dardennii they are slender andcompressed. There are, of course, comparable interspecific differences in the occlusal outline of the dentary.In Limnotilapia dardennii the lateral arms of the dentary are protracted relative to the trans-versely directed anterior part of the bone, and the outline of the whole bone is similar to that ofthe premaxilla. In Simochromis diagramma the dentary, like the premaxilla, is foreshortened, withthe short lateral dentigerous arms (about equal in length to the transverse part) meeting theslightly curved transverse portion at almost a right angle. The dentary in S. diagramma alsodiffers from that of L. dardennii in having virtually no upward sweep to its coronoid portion; inL. dardennii this region slopes upward at a gentle but noticeable angle. Seen in these terms, the osteological 'morphological gap' separating the taxa would appear tobe a more substantial one than that expressed in Regan's (1920) key and generic synopsis. But,the 'gap' is bridged when one examines the premaxilla and dentary of Limnotilapia loocki Poll,1949 (see Poll, 1956 : 62, fig. 10 for an expanded description of the species, and illustrations ofthe jaws and dentition). The morphology of both these bones in L. loocki is virtually intermediate between those inL. dardennii and S. diagramma. Thus, it is impossible to differentiate the 'genera' on the osteologi-cal features characterizing the jaws of the type species. Furthermore, the external oral charactersused by Regan (1920) also intergrade when growth-series of the type species are examined, andI have been unable to detect other characters that might serve to distinguish the taxa (it beingunderstood that the 'genera' are being interpreted here, as they were by Regan, merely on thepresence of a discrete morphological gap that is 'greater' than one which might be used tocharacterize species). There would, therefore, seem to be no grounds for treating Limnotilapia andSimochromis as distinct genera, the more so when one considers the various (and apparentlysynapomorphic) features that are shared by all but one of their included species. Limnotilapia loocki (like L. dardennii, Simochromis diagramma, S. babaulti Pellegrin, S. curvifronsPoll and S. marginatus Poll) has, in both jaws, slender-shafted, recurved, outer teeth with markedlycompressed and expanded, obliquely bicuspid crowns, a greatly reduced (or absent) interspacebetween the numerous inner and single outer tooth rows in both jaws, a densely toothed lowerpharyngeal bone (the teeth fine and compressed) and a strongly decurved anterior profile to theneurocranium (where, in some species, the ethmovomerine region is almost vertically inclined)In all these species, too, the chest scales are small, deeply embedded and have an abrupt sizedemarcation with the larger scales on the anterior abdominal region of the body. For the moment it is these apparently apomorphic features which should be used to define thegenus Simochromis Blgr., 1898 (with which is now included, as a junior synonym, the genusLimnotilapia Regan, 1920). The one species not included in the character analysis given above is Limnotilapia trematoce-phala (Blgr., 1901), a taxon known only from its holotype. I have not, of course, been able toexamine all the relevant osteological features in this specimen, but its relatively sparsely toothedlower pharyngeal bone, the morphology of its outer row jaw teeth (which are without noticeablycompressed, expanded and obliquely bicuspid crowns, and which are not strongly recurved), andits relatively large pectoral scales, all suggest that the species probably belongs to a differentlineage and should not, therefore, be included in the genus Simochromis. For the moment it is impossible to indicate the phyletic relationships of the genus Simochromis,either within or without the cichlid flocks of Lake Tanganyika. Much further research will berequired before this can be achieved (and will also be needed before a generic placement of''Limnotilapia'' trematocephala can be effected). As was noted in my paper on the pharyngeal apophysis in African cichlids (Greenwood, 1978),Simochromis dardennii has a near-typical Tilapia-type of apophyseal structure. Simochromisloocki, on the other hand, has an apophysis of the modified Tropheus-type; the basioccipital isinflated and bullate, with its ventral tip almost reaching the level of the parasphenoidal facets butnot contributing in any way to the articular surface provided by these facets. In its generalorganization, the apophysis in S. loocki is intermediate between the Tilapia and Tropheus types A REVISION OF THE HAPLOCHROMIS GENERIC CONCEPT 319 (see Greenwood, 1978), but differs from the modal condition of both types in having the basiocci-pital noticeably inflated. Since S. dardennii (with a Tilapia-type apophysis) has the least specialized premaxillary anddentary of any Simochromis species, and since S. babaulti and S. diagramma have the mostderived jaws (the species having, respectively, Tropheus and near Haplochromis type apophyses;see Greenwood, 1978), it is tempting to conclude that in this lineage the Tilapia-type apophysisis the plesiomorph one. That S. loocki (whose jaw morphology is intermediate between that ofS. dardennii and those of the other Simochromis species) has an apophysis intermediate betweenthe Tilapia and Tropheus types, would also seem to support this hypothesis. Acknowledgements I am deeply indebted to my colleague, Gordon Howes, for all the assistance he has given me inthe preparation of this paper, and in particular for his skill and patience in preparing theillustrations. For the loan and gifts of specimens used in this work, I gratefully acknowledge thecooperation of the Curator of Fishes, Museum for Naturkunde, Humboldt-Universitat, Berlin(D.D.R.); Dr R. A. Jubb and Mr P. S. Skelton, Albany Museum, South Africa; Dr D. F. E.Thys van den Audenaerde, Musee Royal de 1'Afrique Centrale, Tervuren; Dr J.-P. Gosse,Institut Royal des Sciences Naturelles de Belgique, Brussels; Dr M. L. Bauchot, Museum Nationald'Histoire Naturelle, Paris; Dr H. Wilkens, Zoologisches Institut und Zoologische Museum,University of Hamburg; Dr J. E. Bohlke, Academy of Natural Sciences, Philadelphia; andDr M. J. Penrith, State Museum, Windhoek. Finally, it is my pleasure to thank my colleagues of the freshwater fish section (then includingDr Richard Vari, a NATO postdoctoral research fellow) for the innumerable arguments we havehad on the subject of phylogenetic systematics. Axelrod, H. R. & Burgess, W. E. 1977. African cichlids of Lakes Malawi and Tanganyika. New Jersey. Beadle, L. C. 1974. The inland waters of tropical Africa. London. Bell-Cross, G. 1975. A revision of certain Haplochromis species (Pisces : Cichlidae) of Central Africa. Occ. Pap. natn. Mus. Rhod. ser B. 5 (7) : 405-464. 1976. The fishes of Rhodesia. Salisbury. Berry, L. 1976. The Nile in the Sudan, geomorphological history. Monographiae biol. 29 : 11-19.Boulenger, G. A. 1899. A revision of the African and Syrian fishes of the family Cichlidae. Part II. Proc. zool. Soc. Loud. 1899 : 98-143.1902. List of the fishes collected by Mr W. L. S. Loat at Gondokoro. Ann. Mag. nat. Hist. (7) 10 : 260-264. 1906. Descriptions of new fishes discovered by Mr E. Degen in Lake Victoria. Ann. Mag. nat. Hist. (7) 17 : 433-452.1907. Fishes of the Nile. London. 1915. Catalogue of the fresh-water fishes of Africa 3. London. Du Plessis, S. S. & Groenewald, A. A. 1953. The kurper of Transvaal. Fauna Flora Pretoria 3 : 35-43.Fryer, G. & lies, T. D. 1972. The cichlid fishes of the Great Lakes of Africa. Their biology and evolution. Edinburgh.Greenwood, P. H. 1954. On two species of cichlid fishes from the Malagarazi river (Tanganyika), with notes on the pharyngeal apophysis in species of the Haplochromis group. Ann. Mag. nat. Hist. (12) 7 401-414. 1956a. A revision of the Lake Victoria Haplochromis species (Pisces, Cichlidae), Part I. Bull. Br. Mus. nat. Hist. (Zool.) 4 : 223-244. \956b. The monotypic genera of cichlid fishes in Lake Victoria. Bull. Br. Mus. nat. Hist. (Zool.) 3: 295-333. 1959#. The monotypic genera of cichlid fishes in Lake Victoria. Part II. Bull. Br. Mus. nat. Hist. (Zool.) 5: 163-177. 19596. Quaternary fish fossils. Explor. Pare. natn. Albert Miss. J. de Heinzelin de Braucourt 4 : 1-80. 1960. A revision of the Lake Victoria Haplochromis species (Pisces, Cichlidae), Part IV. Bull. Br. Mus. nat. Hist. (Zool.) 6 : 227-281. 320 P. H. GREENWOOD 19650. Environmental effects on the pharyngeal mil! of a cichlid fish, Astatoreochromis alluaudi, and their taxonomic implications. Proc. Linn. Soc. Loud. 176 : 1-10.19656. The cichlid fishes of Lake Nabugabo, Uganda. Bull. Br. Mus. not. Hist. (Zool.) 12 : 315-357. 1967. A revision of the Lake Victoria Haplochromis species (Pisces, Cichlidae), Part VI. Bull. Br Mus. not. Hist. (Zool.) 15 : 29-119. 1971. On the cichlid fish Haplochromis wingatii (Blgr.), and a new species from the Nile and Lake Albert. Revue Zool. Bot. afr. 84 (3-4) : 344-365. 1973. A revision of the Haplochromis and related species (Pisces, Cichlidae) from Lake George, Uganda. Bull. Br. Mus. not. Hist. (Zool.) 25 : 139-242. 19740. Cichlid fishes of Lake Victoria, east Africa: the biology and evolution of a species flock. Bull. Br. Mus. not. Hist. (Zool.) Suppl. 6 : 1-134. 19746. The Haplochromis species (Pisces : Cichlidae) of Lake Rudolf, east Africa. Bull. Br. Mus. not. Hist. (Zool.) 27 : 139-165. 1976. Fish fauna of the Nile. Monographiae biol. 29 : 127-141. 1978. A review of the pharyngeal apophysis and its significance in the classification of African cichlid fishes. Bull. Br. Mus. nat. Hist. (Zool.) 33 : 297-323. & Barel, C.D.N. (1978) A revision of the Lake Victoria Haplochromis species (Pisces : Cichlidae), Part VIII. Bull. Br. Mus. nat. Hist. (Zool.) 33 : 141-192.Hecht, M. K. & Edwards, J. L. 1977. Phylogenetic inference above the species level. NATO Advanced Study Inst. ser.A. 14 : 3-51. Hennig, W. 1 966. Phylogenetic systematics. Urbana.Hilgendorf, E. 1888. Fische aus dem Victoria-Nyanza (Ukerewe-See). Sber. Ges. naturf. Freunde Berl. 1888 : 75-79. Jubb, R. A. 19670. Freshwater fishes of southern Africa. Cape Town.19676. A new Serranochromis (Pisces, Cichlidae) from the Incomati river system, eastern Transvaal, South Africa. Ann. Cape prov. Mus. 6 (5) : 55-62. 1968. A new Chetia (Pisces, Cichlidae) from the Incomati river system, eastern Transvaal, South Africa. Ann. Cape prov. Mus. 6 (7) : 71-76.Lacepede, B. G. E. (1803). Histoire naturelle des poissons 4. Paris. Livingstone, D. A. 1976. The Nile - palaeolimnology of headwaters. Monographiae biol. 29 : 21-30.McMahon, J. P., Highton, R. B. & Marshall, T. F. de C. 1977. Studies on biological control of inter-mediate hosts of schistosomiasis in western Kenya. Envir. Conserv. 4 (4) : 285-289.Nelson, G. J. 1972. Phylogenetic relationship and classification. Syst. Zool. 21 (2) : 227-231.Patterson, C. & Rosen, D. E. 1977. Review of ichthyodectiform and other Mesozoic teleost fishes and the theory and practice of classifying fossils. Bull. Am. Mus. nat. Hist. 158 : 81-172.Pellegrin, J. 1903. Contribution a 1'etude anatomique, biologique et taxonomique des poissons de la famille des cichlides. Mem. Soc. zool. Fr. 16 : 41-402. 1936. Contribution a 1'ichthyologie de 1' Angola. Archos. Mus. Bocage 7 : 45-62. Penrith, M-L. 1970. Report on a small collection of fishes from the Kunene river mouth. Cimbebasia ser A. 1 : 165-176.Pfeffer, G. 1893. Ostafrikanische Fische gesammelt von Herrn Dr F. Stuhlmann. Jb. hamb. wiss. Anst. 10: 131-177.Poll, M. 1932. Contribution a la faune des Cichlidae du lac Kivu (Congo Beige). Revue Zool. Bot. afr. 23(1): 29-35. 1939. Poissons. Explor. Pare. natn. Albert Miss. H. Damas (1935-1936) 6 : 1-73. 1956. Poissons Cichlidae. Result, sclent. Explor. hydrobiol. lac Tanganika (1946-1947), 3, fasc. 5b : 1-619.1967. Contribution a la faune ichthyologique de 1' Angola. Publicoes cult. Co. Diam. Angola no. 75 : 1-381. 1974. Contribution a la faune ichthyologique du lac Tanganika, d'apres les recoltes de P. Burchard. Revue Zool. afr. 88 (i) : 99-110.Regan, C. T. 1920. The classification of the fishes of the family Cichlidae -I. The Tanganyika genera. Ann. Mag. nat. Hist. (9) 5 : 33-53. 19210. The cichlid fishes of Lakes Albert, Edward and Kivu. Ann. Mag. nat. Hist. (9) 8 : 632-639. 19216. The cichlid fishes of Lake Nyasa. Proc. zool. Soc. Land. 1921 : 675-727. 19220. The classification of the fishes of the family Cichlidae. - II. On African and Syrian genera not restricted to the Great Lakes. Ann. Mag. nat. Hist. (9) 10 : 249-264.19226. The cichlid fishes of Lake Victoria. Proc. zool. Soc. Lond. 1922 : 157-191. Rzoska, J. 19760. The geological evolution of the river Nile in Egypt. Monographiae biol. 29 : 2-4. A REVISION OF THE HAPLOCHROMIS GENERIC CONCEPT 19766. Pleistocene history of the Nile in Nubia. Monographiae biol. 29 : 5-9.1976c. Descent to the Sudan plains. Monographiae biol. 29 : 197-214. 321 Schaeffer, B., Hecht, M. K. & Eldredge, N. 1972. Phylogeny and paleontology. Evolut. Biol. 6 : 31-57.Thys van den Audenaerde, D. F. E. 1963. Descriptions d'une espece nouvelle d' Haplochromis (Pisces, Cichlidae) avec observations sur les Haplochromis rheophiles du Congo oriental. Revue Zool. Bot. afr. 68 (1-2) : 140-152. 1964. Les Haplochromis du Bas-Congo. Revue Zool. afr. 70 (1-2) : 154-173. Trewavas, E. 1933. Scientific results of the Cambridge expedition to the East African lakes, 1930-1. II. The cichlid fishes. /. Linn. Soc. (Zool.) 38 : 309-341. 1935. A synopsis of the cichlid fishes of Lake Nyasa. Ann. Mag. nat. Hist. (10) 16 : 65-118. 1938. Lake Albert fishes of the genus Haplochromis. Ann. Mag. nat. Hist. (11) 1 : 435-449. 1942. The cichlid fishes of Syria and Palestine. Ann. Mag. nat. Hist. (11) 9 : 526-536. 1961. A new cichlid fish in the Limpopo basin. Ann. S. Mus. 46 (5) : 53-56. 1964. A revision of the genus Serranochromis Regan (Pisces, Cichlidae). Annls. Mus. r. Congo beige. Ser. 8vo, Zool. no. 125 : 1-58.1973. II. A new species of cichlid fish of rivers Quanza and Bengo, Angola, with a list of the known Cichlidae of these rivers and a note on Pseudocrenilabrus natalensis Fowler. Bull. Br. Mus. nat. Hist. (Zool.) 25 : 27-37. & Thys van den Audenaerde, D. F. E. 1969. A new Angolan species of Haplochromis (Pisces, Cichlidae). Mitt. zool. Stlnst. Hamb. 66 : 237-239. Vandewalle, P. 1973. Osteologie caudale des Cichlidae (Pisces, Teleostei). Bull. Biol. Fr. Belg. 107 (4) :275-289. Voss, J. 1977. Les livrees ou patrons de coloration chez les poissons cichlides Africaines. Revue franc.Aquariol.4(2):33-8l. Werner, Y. L. 1976. Notes on reproduction in the mouth-brooding fish Haplochromis flaviijosephi(Teleostei : Cichlidae) in the aquarium. /. nat. Hist. 10 : 669-680. Wickler, W. 1962a. Ei-Attrappen und Maulbriiten bei afrikanischen Cichliden. Zeit. Tierpsychol. 19 (2) :129-164. 19626. Egg-dummies as natural releasers in mouth-breeding cichlids. Nature 194 : 1092-1093. 1963. Zur Klassification der Cichlidae, am Beispiel der Gattungen Tropheus, Petrochromis, Haplo-chromis und Hemihaplochromis n. gen. (Pisces, Perciformes). Senckenberg. biol. 44 : 83-96. Index The species discussed in this paper are here indexed under their former generic names. Each entry isfollowed by two numbers; the first refers to the page on which the species is listed in its new generic groupand the second to the page on which that genus or subgenus is described. Astatoreochromis alluaudi 286 285 Chetia brevis 284 281 C. flaviventris 307 307 Chromis monteiri 294 294 Haplochromis acuticeps 312 312 H. albertianus 293 290 H.albolabris 312 312 H. angolensis 312 312 H. annectidens 280 278 H. astatodon 280 278 H. avium 293 290 H. bakongo 293 290 H.bloyeti 283 281 H.burtoni 284 281 H. buysi 312 312 H. callipterus 284 281 H. carlottae 305 303 H. codringtoni 305 303 H. coulteri 304 303 H.darlingi 311 310 H. demeusii 293 290 H. desfontainesi 283 281H. dolorosus 283 281H. fasciatus 293 290H. flaviijosephi 283 281H.giardi 305 303H. greenwoodi 304 303H. horii 289 287H.humilis 312 312H.limax 280 278H.lividus 280 278H. loati 293 290H. luluae 289 287H. macconneli 293 290H.machadoi 297 295H. mahagiensis 293 290H. mellandi 305 303H. moeruensis 293 290H. mor timer i 305 303H. multiocellatus 312 312H.nubilus 283 281H. obliquidens 280 278 322 H. oligacanthus 289 287H. pectoralis 289 287H. petronius 293 290H. pharyngalis 293 290H.polli 289 287H. polyacanthus 297 295H.rudolfianus 293 290H. stappersi 284 281H. straeleni 286 285H. swynnertoni 284 281H. thysi 305 303H. torrenticola 297 295H. turkanae 293 290H. vanderhorsti 286 285H. welwitschii 312 312 P. H. GREENWOOD H. wingatii 293 290 Orthochromis malagaraziensis 297 295 Paratilapia toddi 294 294 Rheohaplochromis torrenticola 297 295 Sargochromis codringtoni 305 303 5. mellandi 305 303 Serranochromis angusticeps 302 299 S.yama 303 299 5. longimanus 302 299 5. macrocephalus 302 299 5. meridionalis 303 299 5*. robustus 302 299 5. .S/K?/ 302 299 5. stappersi 302 299 5. thumbergi 302 299 Manuscript accepted for publication 20 April 1978 British Museum (Natural History)Monographs & Handbooks The Museum publishes some 10-12 new titles each year on subjectsincluding zoology, botany, palaeontology and mineralogy.Besides being important reference works, many, particularly amongthe handbooks, are useful for courses and students' backgroundreading. Lists are available free on request to : Publications Sales British Museum (Natural History) Cromwell Road London SW7 5BD Standing orders placed by educational institutions earn a discountof 10% off our published price. Titles to be published in Volume 35 A revision of the 'acaecate' earthworms of the Pheretima group(Megascolecidae: Oligochaeta) : Archipheretima, Metapheretima,Planapheretima, Pleionogaster and Polypheretima. By E. G. Easton. Miscellanea The planktonic copepods of the northeastern Atlantic Ocean:Harpacticoida, Siphonostomatoida and Mormonilloida. By G. A.Boxshall. Towards a phyletic classification of the 'genus' Haplochromis (Pisces,Cichlidae) and related taxa. Part I. By Peter Humphry Greenwood. A revision of the British species of the genus Phthiracarus Perty, 1841(Cryptostigmata : Euptyctima). By B. W. Parry. Type set by John Wright & Sons Ltd, Bristol and Printed by Henry Ling Ltd, Dorchester Bulletin of the British Museum (Natural History) A revision of the British species of thegenus Phthiracarus Perty, 1841(Cryptostigmata: Euptyctima) B. W. Parry Zoology series Vol 35 No 5 28 June 1979 The Bulletin of the British Museum (Natural History), instituted in 1949, is issued in fourscientific series, Botany, Entomology, Geology (incorporating Mineralogy) and Zoology, andan Historical series. Parts are published at irregular intervals as they become ready. Volumes will contain aboutthree hundred pages, and will not necessarily be completed within one calendar year. Subscription orders and enquiries about back issues should be sent to: Publications Sales,British Museum (Natural History), Cromwell Road, London SW7 5BD, England. World List abbreviation : Bull. Br. Mus. nat. Hist. (Zool.) Trustees of the British Museum (Natural History), 1979 This number completes volume 35 ISSN 0007-1498 Zoology series Vol 35 No 5 pp 323-363British Museum (Natural History)Cromwell RoadLondon SW7 5BD Issued 28 June 1979 A revision of the British species of the genusPhthiracarus Perty, 1841 (Cryptostigmata : Euptyctima) B. W. Parry Department of.Zoology, British Museum (Natural History), Cromwell Road, London SW7 5BD Contents Synopsis ............. Introduction ............. Materials and methods ........... External morphology ........... Idiosoma Gnathosoma ............ Legs Review .............. Descriptions of species ........... Genus Phthiracarus Perty .......... Key to adults of the British species of the genus Phthiracarus .... Phthiracarus affinis (Hull) ......... Phthiracarus anonymum Grandjean ........ Phthiracarus clavatus sp. nov. ......... Phthiracarus flexisetosus sp. nov. ........ Phthiracarus globus sp. nov. ......... Phthiracarus juvenalis sp. nov. ......... Phthiracarus laevigatus (C. L. Koch). ....... Phthiracarus membranifer sp. nov. ........ Phthiracarus murphyi Harding ......... Phthiracarus nitens (Nicolet) ......... Phthiracarus rectisetosus sp. nov. ........ Phthiracarus serrulatus sp. nov. ........ Phthiracarus tardus Forsslund ......... 'Complete' and 'reduced' leg chaetotaxy - a possible basis for a subdivision of thegenus Phthiracarus ........... Acknowledgements ............ References ............. Appendix 1. Species described between 1763 and 1977 currently classified inPhthiracarus. Synopsis A detailed account is presented of the external morphology of the British representatives of the genusPhthiracarus. The literature relating to the genus is reviewed and the status of certain of the older speciesconsidered. Thirteen British species, seven of which are considered to be new, are described, figured andkeyed. Of these, only P. affinis (Hull), P. anonymum Grandjean and P. murphyi Harding were knownpreviously from the British Isles, while P. laevigatus (C. L. Koch), P. nitens (Nicolet) and P. tardusForsslund are recorded for the first time. A neotype for P. affinis is designated. On the basis of the chaeto-tactic pattern of the legs it is suggested that the genus could be divided into two species groups. Bull. Br. Mus. not. Hist. (Zool.) 35 (5) : 323-363. Issued 28 June 1979 323 324 B. W. PARRY Introduction The genus Phthiracarus comprises free-living ptychoid mites occurring predominantly in theupper layers of highly organic forest soils. Containing about 70 nominate species (see Appendix 1),it is the largest of the Euptyctimoid genera and in many respects the most difficult to study. Apartfrom P. anonymum Grandjean and certain of the more recently described species (notably P.mwphyi Harding), the original descriptions have been somewhat superficial and it is even doubt-ful whether some of the nominate species listed in Appendix 1 have been correctly assigned toPhthiracarus. Partial revisions of the genus have been published by Jacot (1930, 1936, 1938 &1939), Feider & Suciu (1957) and van der Hammen (1963 & 1964) but only two of the speciesredescribed, namely, P. laevigatus (C. L. Koch) and P. nitens (Nicolet), can now be positivelyidentified. The only substantial keys to the genus are those published by Willmann (1931),Sellnick (1960), and Gilyarov & Krivolutsky (1975), all of which employ characters that haveproved generally to be useless for species differentiation. Materials and methods This revision is based on a comprehensive survey of the literature and detailed morphologicalstudies of all the available Phthiracarus material from widely separated areas in the British Isles.A large part of the material was taken from the unnamed and unsorted collections of the BritishMuseum (Natural History). Additional material was obtained from a series of fermentation andhumus layer samples collected under stands of beech, larch, oak, Scots pine and Sitka spruce atthe following four areas: The Woburn Estate, Bedfordshire; New Forest, Hampshire; TinternForest, Monmouthshire; Alice Holt Forest, Surrey. These four areas were sampled during theperiod April 1972 to October 1973 as part of a study designed to compare the effects of hardwoodand coniferous tree species on populations of Euptyctima and full descriptions of the samplingsites will be published elsewhere. The mites were extracted using a 'controlled-gradient' funnelapparatus similar to that described by Macfadyen (1961). All the available type material ofPhthiracarus species has also been examined. For detailed studies of the external morphology, the mites were cleared and softened by heatingin a test tube of 75 % lactic acid in a boiling water bath, the duration of heating being dependenton the degree of sclerotization. Each mite was then transferred to a small quantity of Berlese'sfluid on a slide and dissected using two fine needles. Cavity slides containing lactic acid were usedfor temporary preparations of the aspis, notogaster, ventral plates and ovipositor. Permanentpreparations of the legs, chelicerae and infracapitulum requiring examination under oil immersionwere made on plain slides in Berlese's fluid. For each species measurements were taken from all the available specimens. The length of theaspis was taken along the mid-dorsal line and the greatest width as the transverse distance betweenthe antiaxial margins of the bothridia. The sensillus, interlamellar and lamellar setae were mea-sured with the aspis mounted dorsally and the rostrals with the aspis positioned laterally. Thenotogaster was measured in lateral aspect and the length was taken from the anterodorsal limitof the collar to a point just ventral to seta h\. The greatest depth of the notogaster was measuredbetween the seta e\ and the ventral margin. Each chelicera was measured from the base of theprincipal segment to the end of the fixed digit. For detailed study of the leg chaetotaxy, the legswere positioned laterally. Morphological studies were also undertaken using the scanning electron microscope - goodresults being obtained using air-dried spirit-preserved material. Any foreign matter adhering tothe specimens was first removed by brief treatment in an ultrasonic bath. The mites were thensoaked in a small quantity of an anti-static solution of 0-5 % 'Duron' in isobutyl alcohol for aperiod of 12-24 h (Sikorski el al., 1967). It was found that this treatment eliminated any 'charging'due to incomplete coating of cavities such as the bothridia. After soaking, the specimens wereremoved from the solution, washed in isobutyl alcohol and allowed to dry. The mites were stuckonto specimen stubs using double-sided adhesive tape and coated with a 20 nm layer of evaporatedgold. THE GENUS PHTHIRACARUS 325 External morphology The following account of the external morphology of Phthiracarus refers to the adult only; fulldescriptions of the immature stages will form the basis of another paper. The setal nomenclatureused in the later works of Grandjean has been followed throughout the account. Idiosoma ASPIS; Fig. 1B-D; PI. la, e): A pair of oval weakly-sclerotized areas anterodorsally marks thepositions of the retracted chelicerae. The ventral margin of the aspis is reflexed to form theaspal rim (a.r.) and there is a distinct lateral ridge (l.r.). The bothridium (b.) has an inner multi-chambered wall and a smooth outer one from which three finger-like chitinous tracheoles arise andare directed mid-dorsally. The margin of the bothridial aperture is thickened (as shown by thearrow in PI. le) and flanked posteriorly by a pronounced scale. There are three pairs of procum-bent dorsal setae, the rostrals (ro), lamellars (la) and interlamellars (//), and two pairs of setaelaterally, the exobothridials (ex) and the sensilli. In most of the species examined, setae // and laare located at the level of the bothridia, la being somewhat shorter than //. The sensilli are variablein form and so provide a useful taxonomic feature. In some species they are short, ovate orlanceolate while in others they are long, narrow and tapering. The sensillar margin may beserrated (PI. la) and in P. serrulatus sp. nov. it bears a number of straight-edged teeth sub-terminally. The sensillus is most easily observed in scanning electron micrographs as in flattenedslide preparations its appearance can depend very much on orientation. NOTOGASTER (Fig. 1A, E; PI. le): The anterior margin of the notogaster is well sclerotized and,following Jacot (1930), can be subdivided into three regions: the thickened collar (C), thepseudo-stigmatic [sensillar] notch (N) (PI. le) and the lappet (L) which projects somewhat anteriorly. Ofthe 15 pairs of setae, 14 are regarded as being homologues of ci_3 and cp, d\-2, 1-2, A 1-3 andpsi-3 of the holotrich nomenclature, and the additional seta as ps*. The distributional pattern ofnotogastral setae is essentially similar in all the British species but the relative lengths and attitudesof the setae vary considerably from one species to another. The vestiges of setae (f\) and (/2) arethought to be represented by two pairs of subcuticular structures located posterolaterally(Grandjean, 1950). Vestigial f\ normally lies between setae h\ and/wi and/2 between setae h\ andhi but in certain small species (for example, P. serrulatus} f\ is closely associated with the seta hi.There are four pairs of prominent subcuticular fissures: the anteriors (id) and medians (im) aresituated just posterior to seta cp while the posterior pleurals (ip) and infrapleurals (ips) (whenpresent) are situated on either side between setae /*2 and h$ and between setae ps$ and ps*respectively. ANO-GENITAL REGION (Figs 2E; 3B; PI. Ib): On each anal plate there are five setae. Two analsetae an\-2 are located on the paraxial margin and three adanals ad\-$ submarginally ; setae ad\-2are often vestigial. Each anal plate has a prominent hood-like lobe located ventro-anteriorly onits paraxial margin and in the so-called 'left fitting' arrangement (van der Hammen, 1963) thelobe on the right-hand plate overlaps that on the left-hand plate while in the 'right fitting' arrange-ment (as shown by the arrow in Fig. 2E) the reverse is true. Van der Hammen has suggested thatthe arrangement of these interlocking lobes and the condition of setae ad\-2 (present or vestigial)could be useful taxonomic features. This view is not, however, supported by the present studysince these two features have been found to exhibit considerable intraspecific variation. On each genital plate there are two well-developed anterior ridges separated by a median furrow.The furrow bears a single aggenital seta ag\ antiaxially (PI. Ib). There are nine genital setaearranged in two rows. The anterior five setae g\-s are minute and located on the paraxial borderwhile the posterior four setae ge-9 are moderately short and submarginal. There are three pairs ofgenital papillae (g.p.}, the anterior pair being rather small. Elongate oval structures have beenobserved inside the genital papillae and these may prove to be spermatophores. The first twopairs of genital papillae border the ovipositor, which, when fully extended, can be seen to be arather short tube divided into a distal and a proximal portion by a weak circular constriction. 326 B. W. PARRY Fig. 1 Phthiracarus affinis: (A) notogaster, lateral; (B) sensillus and bothridium; (C) aspis,dorsal; (D) aspis, lateral; (E) notogaster, dorsal. THE GENUS PHTHIRACARUS 327 Fig. 2 Phthiracarus affinis: (A) pedipalp; (B) chelicera, antiaxial; (C) chelicera, paraxial ; (D)infracapitulum, ventral ; (E) ano-genital region. 328 B. W. PARRY Fig. 3 Phthiracarus affinis: (A) coxisternal region; (B) ovipositor, lateral. The six coronal (k) setae which Grandjean (1956) found on the constriction in Heminothrustargionii (Berlese) and in the 'higher' oribatid mite Eremaeus hepaticus C. L. Koch are apparentlyabsent in all the British Phthiracarus species. The surfaces of both portions of the ovipositor arestrongly pleated. Distally, three eugenital lobes surround the opening of the ovipositor: anunpaired ventral lobe and a pair of laterodorsal lobes (as shown by the arrows in Fig. 3B). Theventral lobe is triangular in anterior view and bears two pairs of setae distally (\|/i-2), the posteriorpair (11/2) being the shorter. The two laterodorsal lobes are larger, compressed laterally, and eachbears seven setae (TI-V) antiaxially. Feider & Suciu (1957) figured two pairs of setae, presumably (\|/i) and (vj/a), on the ovipositorof P. lentulus (C. L. Koch), and in P. parabotrichus Feider & Suciu, a dorsal group of seven setaeand a smaller ventral group of three setae were shown, possibly (T) and (\|/) respectively. Harding(1976), in his description of P. murphyi, identified 16 setae on the ovipositor: three setae on eachof the laterodorsal lobes, two setae on the ventral lobe and six setae which he considered as thecoronals. Gnathosoma INFRACAPITULUM (Fig. 2D; PI. Ic): The lateral lips (L) bear three pairs of adoral setae (ori_ 3 ),the anterior pair (or\) being brush-like (PI. Ic) and the two posterior pairs weakly serrated. Theinfracapitulum is 'sternarthrous' (Grandjean, 1957) and the rutella (RU) are without atelobasicexpansions. There are three pairs of infracapitular setae: an anterior (a) and a median pair (m)of long smooth setae located on the genae (G) and a rather short posterior pair (h) located onthe hysterostoma (H). Laterally there is a single pair of barbed supracoxal setae (e). PEDIPALPS (Fig. 2A; PI. Id): The pedipalps are only three-segmented. The basal segment,formed from the fused trochanter, femur and genu, bears two setae, the tibia two setae and thetarsus seven setae and a solenidion. The three most distal of the tarsal setae are eupathidial: the THE GENUS PHTHIRACARUS 329 anteroculminal acm, anterior ultimal ul' and posterior ultimal ul" . The subultimal seta sul is aminute spine-like process at the base of seta ul' (as shown by the arrow in PI. Id) and also appearsto be eupathidial. CHELICERAE (Fig. 2B, C) : Both the fixed and the movable digits are dentate. The movable digithas four teeth and the fixed digit carries five. The latter are arranged in two rows, an outer oneof two and an inner one of three teeth. The large principal segment which terminates in the fixeddigit, bears a number of short conical spines on the antiaxial surface and a larger number ofsharply pointed spines paraxially; the spines are distributed extensively on the paraxial surfacebut are restricted to a more compact zone antiaxially. There are two cheliceral setae, an anteriorseta chb inserted on the antiaxial surface and & posterior seta cha located dorsally. Both setae areserrated, cha being somewhat longer than chb. Legs Legs II to IV are approximately equal in length while leg I is longer and more robust. The indivi-dual epimera are separate and, except for epimera II, each bears a single seta, la, 3a and 4arespectively (Fig. 3A). All the legs have five segments: the trochanter, femur, genu, tibia andtarsus, and terminate in a single claw bearing two ventral teeth and an antero- and posterolateralrow of serrations (PI. 2c). SOLENIDIA (PI. 2a, b, e): The solenidiotaxy (12-1-3; II 1-1-2; III 1-1-0 and IV 0-1-0) isconstant in the 13 species examined and typical of that found in other Phthiracaridae. All the B Fig. 4 Phthiracarus affinis, leg 1 : (A) tarsus, dorsal aspect; (B) trochanter to tibia, posterolateralaspect. 330 B. W. PARRY tc" Fig. 5 Phthiracarus affinis, legs II-IV; (A) leg II, posterolateral aspect; (B) leg III, anterolateralaspect; (C) leg IV, anterolateral aspect. (Fig. 5A-C are drawn at the same magnification.) THE GENUS PHTHIRACARUS 331 tarsal solenidia are transversely striated as described by Grandjean (1935) for Oribotritia berlesei(Michael). On tarsus I the solenidion GDI is closely associated with the famulus e (PI. 2a) which isshort and rugose. Solenidion 0)2 is the longest of the three tarsal solenidia and has a small distalcoupling seta (PI. 2b). Harding (1976) described such a setal/solenidial association in P. murphyiand in P. nitens but noted that solenidion 02 was apparently free in P. anonymum. In the presentstudy the scanning electron microscope has revealed the presence of a distal coupling seta in allthe British species. Although usually short and simple, in P. rectisetosus sp. nov. this seta is long,prominent and apparently divided into two parts by a longitudinal constriction, the distal partbeing produced into a scabre-shaped process reminiscent of that found in species of the genusSteganacarus (see Parry, 1978). On all legs the tibial solenidion cp is coupled with a reduced dorsalseta (PI. 2e) while on genu I solenidion crj is coupled with a reduced lateral seta. LEG SETAE (Figs 4; 5; 14; PI. 2d): In all the larger species examined the formulae for the legsetae are: I (1-4-2-5-16-1); II (1-3-2-3-12-1); III (2-2-1-2-10-1) and IV (2-1-1-2-10-1). Thiscomplement will be referred to as the 'complete chaetotaxy type' (Figs 4; 5). On tarsus I only 16of the 20 setae regarded by Grandjean (1940) as being characteristic of 'higher' Oribatei arepresent, the primilaterals and postlarvals always being absent. Four setae surround the base of theclaw, namely, a dorsal pair of pr orals (p) and a ventral pair of unguinials (u). Three pairs of setaeare located posterodorsally to the prorals: the iterals (if), tectals (tc) and fastigials (ft). Ventrally,behind the unguinials, there is an unpaired subunguinial seta s and a pair of primiventral setae(pv). A single pair of anterolateral setae (a) is located laterally behind the prorals and theunguinials. On tarsi II to IV there is a reduction in the number of setae to 12, 10 and 10 respectively: setae(it), a' and e are absent on tarsi II to IV, setapv" on tarsus III, seta a" on tarsi III and IV and setaft" on tarsus IV. Furthermore, the tarsal setae exhibit considerable variety in form. On tarsus Isix of the setae (s, (it), (p) and a') are hollow eupathidia. On all four tarsi setae (ft) and (pv),together with a" on tarsi I and II, are generally more or less straight, circular in section and beartwo or three rows of lateral serrations. In certain species (for example, P. globus sp. nov.) setaft" on tarsus II is hooked distally. The other tarsal setae, (tc) and (u) on tarsus I and (tc), (u), (p)and s on tarsi II to IV, are ribbon-like, hooked distally and covered with whorls of spicules in themiddle third. Such setal ornamentation is, however, only discernible in the larger species of thegenus. The setation of the four proximal leg segments is shown in Table 1 . Apart from tibia I whichbears a whorl of five setae (d, I', I", v' and v"), each of the other segments bears an incompletewhorl of one to four setae. Seta d on femur I is somewhat thickened, serrated and curved distally(PI. 2d) in all the species examined except P. clavatus sp. nov. and P. globus sp. nov. where it israther long, straight and only weakly serrated. On all segments setae (/) and (v) carry two or threerows of serrations. Table 1 Chaetotaxy of the four proximal leg segments in Phthiracarus Segment Leg I II III IV In all the smaller species of the genus (for example, P. tardus Forsslund) there are fewer setaeon legs I, II and IV (Fig. 14): tarsus I bears 15 setae (a 1 absent), tarsi II and IV usually bear 11and 9 setae respectively (s absent), femur I bears 3 setae (v' absent) and genu IV is without anysetae (/' absent). Thus the setal formulae (referred to here as the 'reduced chaetotaxy type') are:I (1-3-2-5-15-1); II (1-3-2-3-11-1); III (2-2-1-2-10-1) and IV (2-1-0-2-9-1). In P. anonymum(a variant of the 'reduced phaetotaxy type') the number of setae on tarsus IV is further reduced 332 B. W. PARRY by the absence of seta pv'. Although the total number of setae on leg III is constant throughoutthe genus, in species of the 'complete chaetotaxy group' seta pv" is absent and seta s presentwhile the reverse is true in the 'reduced' group. Review Perty proposed the genus Phthiracarus in 1 839 and two years later created the 'family' Phthiracarea(now Phthiracaridae) for the single species P. contractilis. Perty's original specimens are presumedto be lost and his figures (subsequently published by Claparede, 1868) and description are suchas to make the specific identity of contractilis impossible to determine. Acarus piger Scopoli, 1763, the oldest species currently classified in Phthiracarus, was originallyassigned to the genus by Oudemans (1915). The mite described by Scopoli, for which there is notype material available, is undoubtedly ptychoid but there is no evidence to suggest that it is aspecies of Phthiracarus - it is probably a member of the Euphthiracaroidea (see Jacot, 1930). The systematic position of Oribates dasypus Duges, 1 834 is also somewhat uncertain althoughthe species is evidently ptychoid. Michael (1888) recorded dasypus in the British Isles. The speci-men labelled Hoplophora* dasypus from Theydon Bois in the Michael Collection (deposited inthe BMNH) is P. clavatus. In 1841 ten species of Hoplophora, ninef of which are currently classified in Phthiracarus, weredescribed by Koch from woodland habitats near Regensburg. While it seems probable that thesemites have been correctly assigned to Phthiracarus (with the ecxeption of H. testudinea which ispossibly a member of the Euphthiracaroidea), only two of Koch's descriptions refer to 'keycharacters' which might permit certain reidentification. In comparison with the other Regensburgspecies, H. globosa is very 'globular' while in H. laevigata the notogaster is 'angled' at the level ofseta c\. The remaining six species can only be divided into two groups on the basis of theirnotogastral setae; crinita, ferruginea and longula are each characterized by 'long setae' while theother three species (lentula, lucida and straminea) are all described as being 'sparsely setose'.Despite the inadequacy of Koch's descriptions and the apparent absence of any type material,various interpretations of his species have been published, amongst others by Jacot and van derHammen. In Les Phthiracaridae de Karl Ludwig Koch, Jacot (1936) redescribed six species fromtopotypic material but neglected details of the leg and notogastral chaetotaxy, now regarded asbeing essential for the separation of Phthiracarus species. More recently, van der Hammen (1963),in one of his series of papers on the Phthiracaridae, has published a detailed description of P.laevigatus (from material collected at Regensburg) and has designated a neotype. Van der Hammen(personal communication) also believes that he has topotypic material of Koch's seven otherspecies but until these specimens have been examined it seems advisable to postpone any decisionconcerning their taxonomic status. Hoplophora nitens Nicolet (1855), recorded as common in the woods around Paris, is a Phthira-carus species. The true identity of nitens appears to be doubtful, although van der Hammen'sredescription (see Hammen, 1964) from topotypic material is generally accepted. Hoploderma italicum Oudemans (1907), recorded from Tiarno, Italy, is not based on a typespecimen but on Berlese's description of H. dasypus which Oudemans regarded as being distinctfrom O. dasypus Duges. Van der Hammen (1952) considers the specimens of both Berlese andOudemans as being useless for reidentification purposes. * Certain species now assigned to Phthiracarus have in the past been classified in two other genera, HoplophoraC. L. Koch and Hoploderma Michael. The genus Hoplophora was erected by Koch in 1836 for two species, H.decumana C. L. Koch and H. stricula C. L. Koch, currently classified in Oribotritia and Steganacarus respectively.In 1841 Koch described further species of Hoplophora but did not publish a diagnosis of the genus or designate atype (H. laevigata) until the following year. Jacot's 1928 application to the International Commission on ZoologicalNomenclature for a ruling on the validity of the type designation (Koch, 1842) for a genus first published sixyears earlier (Koch, 1836) was not published until 1946 (see Jacot, 1946). The Commission's subsequent ruling(I.C.Z.N., 1953) allowed H. laevigata to be retained as the type (H. laevigata is here regarded as a species ofPhthiracarus) since the genus was not originally monotypic and did not contain a species called typus or typicus.However, the generic name Hoplophora had been found by Michael (1898) to be preoccupied by Hoplophora Perty,1 833 (Neuroptera), and the new name Hoploderma was proposed. t The tenth species of Hoplophora, H. ardua, is now classified in Rhysotritia. THE GENUS PHTHIRACARUS 333 Hoploderma boreale Triigardh (1910) and Hoploderma affine Hull (1914) are both Phthiracarusspecies. This is evident from the figures of these mites and has been confirmed by examination of'cotype' and syntype material respectively. The characteristic features of these two species are nowcertain. Oudemans (1915) proposed the name Phthiracarus undatus for the 'larve' of Hoplophorastricula (sensu Nicolet, 1855). While Nicolet's figures and description appear to refer to an adultoribatid mite, there is no evidence to suggest a Phthiracarus species. Berlese (1920 & 1923) described six species of Phthiracarus: rotundus, roubali and subglobosusare European while P. nigerrimus was collected from Argentina, P. curtulus from the UnitedStates and P. pudicus from South Africa. The type of each of these species has been examined byDr J. G. Sheals (BMNH) who has found that their condition is such as to make any chaetotacticcharacters impossible to discern. In 1959 van der Hammen reviewed all Berlese's species ofprimitive oribatid mites deposited in the 'Stazione di Entomologia Agraria', Florence, but couldnot confirm the identities of any of the Phthiracarus species. Jacot (1928-1939) described 13 species from North America and a single species (P. insularis)from the Marquesas Islands. Of these, type material is available for eight species (see Appendix 1),seven of which are represented by a number of 'cotypes' while only P. brevisetae is based on aholotype. All Jacot's Phthiracarus specimens are mounted in Canada Balsam, the majority beingentire and uncleared. The shape of the sensillus and the relative lengths and attitudes of the dorsalnotogastral setae can usually be seen in such preparations but the leg chaetotaxy is extremelydifficult to study. In view of the condition of Jacot's material, it seems advisable to postpone anydecision regarding the identities of his Phthiracarus species until all the type specimens have beendismounted and cleared (an exercise which will be complicated by the presence on each 'cotype'slide of additional species of this and other genera). It can, however, be noted that P. brevisetaeappears to be close to if not conspecific with P. laevigatus, while the differences between anonymusamicus and Grandjean's anonymum are evidently not sufficient to warrant subspecific ranking.P. insularis and P. setosellum bryobium possibly have affinities with two British species, P. murphyiand P. clavatus respectively. In 1933 Grandjean published the first of a series of detailed works on the external morphologyof P. anonymum, a species he recorded from rotting wood in his cellar at Perigueux, Dordogne,France. By clearing whole and dissected specimens (Grandjean, 1949) he was able to observethe patterns of setae on the body shields (Grandjean, 1933, 1934 & 1950), which provided newcriteria for the identification of species of this genus. Hitherto, species differentation had beenbased almost entirely on body shape and colour, two characters now known to be uniform inmany Phthiracarus species. Grandjean (1935, 1940 & 1946) also undertook the first detailedstudies of the leg chaetotaxy of oribatid mites, introducing the system of nomenclature now ingeneral use. However, in recent years the majority of Phthiracarus species have been definedsolely in terms of characters visible in undissected material. Leg chaetotactic characters haveonly rarely been studied (van der Hammen, 1963; Sheals, 1965; Ramsay, 1966; Harding, 1976)probably due to difficulties in interpretation. Further Phthiracarus species have been described by Willmann (1932, 1939 & 1951), Woolley(1954) and Forsslund (1956) (see under Descriptions of species). However, P. peristomaticus,recorded by Willmann (1951), from a number of habitats including leaves, turf and subsoil underbuckthorn, guelder-rose and alder, nordlich Moosmiihle, near Vienna, Austria, cannot beidentified either from Willmann's figure or from his description. Moreover, there are no specimensof P. peristomaticus in Willmann's Collection (Dr W. Hirschmann, personal communication).Feider et al. (1957, 1958 & 1968) recorded eight species from Rumania, none of which weredescribed in sufficient detail to permit certain reidentification, although P. baloghi, collected fromoak leaves in lasi, appears to be unique among described species of the genus in having notogastralsetae of two markedly different lengths. Unfortunately, it has not been possible to borrow thetypes of any of the Rumanian species for study. This was also the case with species described byBalogh (1958, 1962, 1963 & 1977) and Krivolutsky (1966 & 1975). Other Phthiracarus specieshave been described from Japan (Aoki, 1958 & 1963), Chile (Hammer, 1962), Nepal (Sheals,1965), New Zealand (Ramsay, 1966), Spain (Perez-Inigo, 1969), Tahiti (Hammer, 1972), the 334 B. W. PARRY Tonga Islands (Hammer, 1973) and the British Isles (Harding, 1976) (see Appendix 1). Of these,P. robertsi, recorded by Sheals from rhododendron litter in Nepal, is of particular interest for,although having certain affinities with Phthiracarus, it shows a general similarity to Steganacarus.The arrangement of setae on the genital and anal plates, while reminiscent of Phthiracarus, isnevertheless 'unusual' for setae ad\^ are almost marginal. The only diagnostic feature whichP. robertsi appears to share with all species of the genus is the presence of a coupled solenidionon tibia IV. The general shape of the aspis and the form of the integumental ornamentation arecharacteristic of Steganacarus species and it is questionable whether P. robertsi should have beenclassified in Phthiracarus (see Sheals, 1969). There have been relatively few reviews of the British species. In his Synonymic catalogue ofBritish Acari, Turk (1953) listed only five species of Phthiracarus: piger (Scopoli) (=Hoplophoradasypus Duges sensu Michael), affine (Hull), anonymum Grandjean, ligneus Willmann andspinosum (Sellnick) (now classified in Steganacarus). Turk does not give sources for individualrecords but the above are presumably based on the following published records: Michael, 1888,Halbert, 1915 and Hull, 1916 (dasypus); Hull, 1914 (affine); Murphy, 1954 (anonymum);Macfadyen, 1952 (ligneus and spinosum). Of these, only P. affinis and anonymum are recognizedin the present revision since the taxonomic status of the other two Phthiracarus species is doubtful. Descriptions of speciesGenus PHTHIRACARUS Perty Hoplophora Koch, 1836 : Hft. 2, Nr. 9. Preoccupied name (Michael, 1898 : 77). Type, by subsequent designation, Hoplophora laevigata Koch, 1841 : Hft. 38, Nr. 16.Phthiracarus Perty, 1839 : column 847. Type, by monotypy, Phthiracarus contractilis Perty, 1841 : 874. Figured by Claparede, 1868 : pi. 36, figs 15-19.Hoploderma Michael, 1898 : 77. Proposed as replacement name for Hoplophora Koch. DEFINITION: Weak to heavily sclerotized Phthiracaridae ranging in length from about 350-1300um (lateral measurement taken in closed position). The integument of the dorsal andventral shields, infracapitulum and chelicerae is densely punctate while that of the appendages issmooth. The interlamellar and lamellar setae are procumbent and the aspis without a mediankeel. The notogaster bears 15 pairs of fine and generally smooth setae. Fissures ip and ips maybe present or absent. The notogaster bears neither a cowl nor a carina. Two pairs of anal setaeare located on the paraxial margins of the anal plates and three pairs of adanals submarginally(the exception being P. anonymum with three pairs of setae located marginally). All are usuallymore or less equal in length although the two posterior pairs of adanal setae may be vestigial.The genital setae are arranged in a pattern of 5+4 along the paraxial margins of the genitalplates. On leg IV the tibial solenidion is coupled. DIAGNOSIS: Phthiracarus is distinguished from other genera of the Phthiracaridae by having acombination of procumbent interlamellar setae and a 2+3 arrangement of setae on the anal plates. Key to adults of the British species of the genus Phthiracarus Only two species can be recognized on the basis of a single character. In P. anonymum seta ad 3 is locatedmarginally (submarginally in all other species) while P. laevigatus appears to differ from all the othermembers of this genus in that the notogaster is strongly arched at the level of seta c { . It has been concluded from an investigation of the external morphology of the British species that thenumber of setae on femur I (4 or 3) and genu IV (1 or 0), the shape of the sensillus, the presence or ab-sence of fissures ip and ips and the relative lengths and attitudes of the notogastral setae are the mostuseful characters for species differentiation. These are the main characters used in the following key. 1 Femur I with four setae (Fig. 4B); genu IV with a single seta (Fig. 5C) .... 2Femur I with three setae (Fig. 14B); genu IV without setae . . . . . .9 2 Notogastral fissures ip and ips absent (Fig. 1A) . . . . . ... 3 Notogastral fissures ip and ips present (Fig. 10D) ........ 6 THE GENUS PHTHIRACARUS 335 3 Sensillus about 80 [xm long, narrow and pointed distally (PI. 4d); notogastral setae shorter ihanc l -d l P.juvenalis sp. nov. (p. 342) Sensillus not of this form; notogastral setae equal to or greater than c, -d { . . . 4 4 Notogastral setae procurved (Fig. 7A); sensillus as in PI. 3f . .P. clavatus sp. nov. (p. 338) - Notogastral setae erect ............ 5 5 Large species, notogaster over 550 \im in length; seta d on femur I straight P. globus sp. nov. (p. 341) - Smaller species, notogaster under 500 [J.m in length; seta d on femur I curved distally (PI. 2d) P. affinis (Hull) (p. 335) 6 Notogaster sharply angled at the level of seta c, when viewed laterally (Fig. 10D) P. laevigatus (C. L. Koch) (p. 344) - Notogaster rounded anteriorly when viewed laterally (Fig. 1A). ..... 7 7 Sensillus 50-60 [xm long, narrow and finely serrated (Fig. 12 A); notogastral setae shorter than c l -d l and procurved ......... P. nitens (Nicolet) (p. 346) - Sensillus not of this form; notogastral setae equal to or greater than c 1 -d 1 . ... 8 8 Notogastral setae procurved ; on tarsus I seta coupled with solenidion co 2 much shorter than famulus ........... P. murphyi Harding (p. 346) - Notogastral setae almost erect; on tarsus I seta coupled with solenidion co 2 almost as long as famulus .......... P. rectisetosus sp. nov. (p. 348) 9 Notogaster with vestigial f v just dorsal to seta h l (Fig. 6E); seta ad 3 located on paraxial margin of anal plate (PI. 3e); tarsus IV with eight setae (Fig. 6B) P. anonymum Grandjean (p. 336) - Notogaster with vestigial /i located on a level with or ventral to seta h l ; seta ad 3 located sub- marginally on anal plate (Fig. 2E); tarsus IV with nine setae (Fig. 14D). ... 10 10 Sensillus about 70 [xm long ............ 11 - Sensillus 30-40 y.m long 12 11 Sensillus with membranous border (Fig. 11 B). . . . P. membranifer sp. nov. (p. 344) - Sensillus serrated distally (Fig. 13B) ..... P. serrulatus sp. nov. (p. 348) 12 Notogastral setae equal to c l -d l and erect; tarsus II with 12 setae . P. tardus Forsslund (p. 351) - Notogastral setae greater than c 1 -d l and slightly flexuose (Fig. 7F); tarsus II with 11 setae P.flexisetosus sp. nov. (p. 340) Phthiracarus affinis (Hull)(Figsl;2;4;5;Pls2a, b, d; 3a, d) Hoploderma affine Hull, 1914 : 287, pi. C9.Phthiracarus affine: Turk, 1953 : 89. ADULT (PI. 3a): Small and moderately sclerotized. The aspis (Fig. 1C, D) ranges in length from223 -253 um with a greatest width of 162-192 um. All the dorsal setae are fine and short.Setae (//) are about 1-5 times the length of setae (Id) and extend two-thirds of the distance betweenthe bases of setae (//) and (ro). The latter do not reach the anterior limit of the aspis. The sensillus(Fig. IB; PI. 3d) is 50 - 60 um long, lanceolate and serrated. The notogaster (Fig. 1A, E) rangesin length from 406 - 487 um with a greatest depth of 294 - 345 urn. All the setae are relativelylong (equal to the distance c\ - d\), fine and erect. Setae c\ and CT, are inserted on the posteriormargin of the collar and seta 02 submarginally. Vestigial f\ is located a short distance posterior toseta hi. The fissures ip and ips are absent. On each anal plate (Fig. 2E) there are three setae; an\and a2 being much longer than ad*. The chelicerae (Fig. 2B, C) are about 121 um long. Theprincipal segment carries 14-26 sharply pointed spines on the paraxial surface and 9-21conical spines antiaxially. The leg chaetotaxy (Figs 4; 5) is of the 'complete type' with the setalformulae: I (1-4-2-5-16-1); II (1-3-2-3-12-1); III (2-2-1-2-10-1) and IV (2-1-1-2-10-1). Ontarsus I the distal seta coupled with solenidion 002 is short; its form can only be seen clearly inscanning electron micrographs (PI. 2a, b). Seta u' on tarsi I and II is often short and thick andresembles a eupathidium. On femur I seta d is short, serrated and curved distally (PI. 2d). DISTRIBUTION: P. affinis is apparently widely distributed in forest soils with a mor humusformation. This species was recorded in the F (fermentation) and H (humus) layers under boththe hardwood and coniferous tree species at each of the four study areas (see p. 324) beingparticularly abundant in the F layer under beech and oak where it constituted 20 - 30 % of theeuptyctimoid population. Material collected from the following localities was also examined.: 336 B. W. PARRY Wytham Woods Estate, Berkshire, 28.X.70 (T. G. Wood); St. Agnes, Isles of Stilly, Cornwall,5.iv.57 (K. H. Hyatt); Bramshill Forest, Hampshire, 6.xii.70 (B. W. Parry); Woodwalton Fen,Huntingdonshire, 20.V.65 (P. N. Lawrence); Keston Bog, Kent, 8.i.56 (P. N. Lawrence); ThetfordChase, Norfolk, 23.vi.71 (B. W. Parry) ; Springwell Forest, Co. Londonderry, 1973 (J. Longworth);as well as material labelled 'Hoploderma affine Hull (Ninebanks)' in the Hull Collection depositedin the BMNH. REMARKS: Hull (1914) recorded affinis in moss in woods and in Sphagnum on moors, WestAllendale, Northumberland and Gibside, Durham and later (1916) included it in his key tospecies of the genus Hoploderma. A holotype does not appear to have been designated and notype material is known to exist. Hull's collection was found to contain one tube labelledHoploderma affine. Three of the specimens are in good condition, conspecific and the shape oftheir sensilli corresponds with Hull's description: 'Pseudostigmatic organs prominent, slender,fusiform, curved outward and forward, rather long, with a fine point'. Moreover, the specimensare of a similar size to that given by Hull (about 420 urn). One of these specimens, BMNH reg.no. 1973.28 (now mounted in Berlese's fluid), is hereby designated as the neotype. The fourthspecimen, although badly damaged, is clearly another larger species with a differently shapedsensillus. The other British material has been compared with the neotype - no morphologicaldifferences apart from size variation could be detected. P. affinis appears to be close to P. crenophilus, a species described by Willmann (1951) from theedge of a marsh, Ebreichsdorf, Austria, and earlier identified as P. borealis (Tragardh) (seeWillmann, 1923, 1928 & 1931). The syntype series (10 specimens collected in Austria, Germanyand Switzerland) has been examined and found to be composed of two species, only one of whichresembles Willmann's figure of crenophilus and also the neotype of P. affinis. However, thenotogastral setae of the latter are considerably shorter than in P. crenophilus. Phthiracams anonymum Grandjean(Fig. 6; PI. 3b, e) Phthiracarus anonymum Grandjean 1933 : 312 (ano-genital region); 1934 : 51 (aspis & notogaster); 1950 :73 (setae /j,/ 2 and/?.v 4 ); van der Hammen, 1965 : 376 (leg chaetotaxy).[Phthiracarus anonymum: Feider & Suciu, 1957 : 24. Misidentification.] ADULT (PI. 3b): Small, weakly sclerotized and opalescent. The aspis (Fig. 6C) ranges in lengthfrom 208 - 248 um with a greatest width of 162 - 172 urn. All the dorsal setae are fine and short.Setae (/'/) are about 1 -5 times the length of setae (la) and extend two-thirds of the distance il-ro.The rostrals which are inserted relatively far apart are widely removed from the anterior margin.The sensillus (Fig. 6D) is short (20 um), ovate and serrated. The notogaster (Fig. 6E) ranges inlength from 406 - 466 um with a greatest depth of 253 - 294 jam. All the setae are short (less thanthe distance c\ - d\), fine and erect. Setae c\ and c^ are inserted on the posterior margin of thecollar and seta ci submarginally. Vestigial/i is located just dorsal to seta h\. The fissures ip and ipsare absent. On each anal plate (PI. 3e) there are five relatively short setae, of which, three,evidently adi and an\-2, are inserted on the paraxial margin, the longest in the row being an\which is approximately twice as long as ad^. The chelicerae are approximately 137 jim in length.The principal segment carries about 12 sharply pointed spines on Jhe paraxial surface and about10 conical spines antiaxially. The leg chaetotaxy is of the 'reduced type' with the setal formulae:I (1-3-2-5-15-1); II (1-3-2-3-11-1); III (2-2-1-2-10-1) and IV (2-1-0-2-8-1). On tarsus I(Fig. 6A) true setae and eupathidia are difficult to distinguish since the former are more or lessstraight distally. The distal seta coupled with solenidion 0)2 resembles that of P. affinis. Seta u' ontarsi I and II is often short and thick and resembles a eupathidium. On tarsus IV (Fig. 6B) setapv' is absent. DISTRIBUTION: P. anonymum, the only endophagous species identified in the present study, isapparently widely distributed in the F layer or mor forest soils. This species was common underboth the hardwood and coniferous tree species at each of the study areas (see p. 324) beingparticularly abundant under oak where it constituted 5 - 10% of the euptyctimoid population. THE GENUS PHTHIRACARUS 337 B Fig. 6 Phthiracarus anonymum: (A) tarsus I, posterolateral aspect; (B) tarsus IV, posterolateralaspect; (C) aspis, dorsal; (D) sensillus and bothridium; (E) notogaster, lateral. (Fig. 6A, B aredrawn at the same magnification.) 338 B. W. PARRY Material was also examined from: Wytham Woods Estate, Berkshire, 28.x. 70 (T. G. Wood);Burnham Beeches, Buckinghamshire, 1964 (G. O. Evans); Bramshill Forest, Hampshire,6.xii.70 (B. W. Parry); Woodwalton Fen, Huntingdonshire, 20.iv.65 (P. N. Lawrence); HollowsWood, Kent, 3.iv.60 (P. N. Lawrence); Grasmere, Westmorland, 3.xii.54 (M. Bacchus); MeathopWood, Westmorland, 19.iii.63 (P. N. Lawrence); Shawley Woods, Worcestershire, 4.X.63 (F.Flowers); Springwell Forest, Co. Londonderry, 1973 (J. Longworth); Perigueux, Dordogne,France (topotypes). REMARKS: In comparison with the other British Phthiracarus species examined, P. anonymumis somewhat atypical: it alone is opalescent; bears /j dorsal to hi; carries ad-}, on the paraxialmargin of the anal plate and lacks the anterior primiventral seta on tarsus IV. The British materialhas been compared with a number of topotypes - no morphological differences could be detected.P. anonymus amicus Jacot, described from deciduous leaf mould, Connecticut Hill, New York,USA, may well prove to be conspecific with P. anonymum. Jacot (1938) based his description onthe position of seta di and the length of seta an\ ; di was located further towards d\ than was infact shown in Grandjean's figure (Grandjean, 1934) while seta an\ appeared to be longer. AlthoughGrandjean's figure does indeed differ in these two respects from Jacot's anonymus amicus, thetopotypic material of anonymum which has been examined agrees well with Jacot's description.A 'cotype' of anonymus amicus (slide no. 32108h2, undissected and mounted in Canada Balsam)has been examined and appears to be close to anonymum although the seta an\ is difficult todiscern. Moreover, Jacot's species (diagonal length of notogaster about 400 um) falls within thesize range given by Grandjean (notogastral length 330 - 420 um). Phthiracarus clavatus sp. nov.(Fig. 7A-C;P1. 3c, f) ADULT (PI. 3c) : Large and strongly sclerotized. The aspis (Fig. 7C) ranges in length from 279 -324 um with a greatest width of 192 - 208 um. All the dorsal setae are long and conspicuous.Setae (//) and (la) are more or less equal in length and both pairs of setae reach the level of therostrals. The latter extend to the anterior margin of the aspis. In the paratype setae (la) are onlyhalf the length of setae (//). The sensillus (Fig. 7B; PI. 3f) is 30 - 40 um long, broadly clavate anddistinctly serrated in the distal half. The notogaster (Fig. 7 A) ranges in length from 619 - 659 umwith a greatest depth of 421 -458 um. All the setae are long (more than the distance c\ -di)and procurved. Setae ci_3 form a row just behind the posterior margin of the collar. Vestigial f\is located a short distance posterior to seta h\. The fissures ip and ips are absent. On each analplate there are five long setae; an\-i and ad$ being more or less equal in length and somewhatshorter than ad\-2. The chelicerae are approximately 182 um in length. The principal segmentcarries about 20 sharply pointed spines on the paraxial surface and about 18 conical spinesantiaxially. The leg chaetotaxy is of the 'complete type' with the setal formulae: I (1-4-2-5-16-1);II (1-3-2-3-12-1); III (2-2-1-2-10-1) and IV (2-1-1-2-10-1). On tarsus I the distal seta coupledwith solenidion 002 is rather short. Seta d on femur I is long, straight and only weakly serrated. TYPES: Holotype, BMNH reg. no. 1976.2.18.1, from mull soil, Meathop Wood, Westmorland,19.iii.63 (P. N. Lawrence). Paratype, 1976.2.18.2, from Phragmites litter, Woodbastwick Marshes,Norfolk, 10.vii.74 (S. J. Moore). DISTRIBUTION: P. clavatus was also recorded from The Woburn Estate, Bedfordshire, 10.iv.72(B. W. Parry) and from Rosthwaite, Cumberland, 18.V.59 (P. N. Lawrence). This species was notabundant in any of the samples examined. REMARKS: P. clavatus appears to be similar to P. borealis (Tragardh) recorded in rotting birchleaves, Sarek, Swedish Lapland. Three 'cotypes' of borealis (cleared but undissected) were ex-amined and found to be generally larger (notogastral length 659 - 842 um) and more heavilysclerotized than clavatus. Moreover, in P. borealis the notogastral setae are erect while in P.clavatus they are procurved. The general form of the sensillus is similar in both species.P. clavatus also resembles P. setosellum bryobium described by Jacot (1930) from upland THE GENUS PHTHIRACARUS 339 Fig. 7A-C Phthiracarus clavatus: (A) notogaster, lateral; (B) sensillus and bothridium; (C)aspis, dorsal. Fig. 7D-F Phthiracarus flexisetosus: (D) aspis, dorsal; (E) sensillus and bothridium; (F)notogaster, lateral. 340 B. W. PARRY swamp moss, East Village, Monroe, Connecticut, USA. However, in comparison with clavatus,the 'cotype' of setosellum bryobium is much smaller (notogastral length about 252 um). Thenotogastral setae appear to be of the same general form in both species. The sensillus, whichappears to be lobular in Jacot's figure, is missing in the 'cotype'. Phthiracams flexisetosus sp. nov.(Fig. 7D-F) ADULT: Medium-sized and moderately strongly sclerotized. The aspis (Fig.7D) ranges in lengthfrom 230- 255 um with a greatest width of 170- 220 um. All the dorsal setae are fine andrather long. Setae (//) are about 1 -5 times the length of setae (la) and equal to the distance il-ro.The rostrals, which are inserted relatively far apart, do not reach the anterior limit of the aspis.The sensillus (Fig. 7E) is 30 - 40 um long, broadly clavate, serrated and closely resembles thatfound in P. clavatus. The notogaster (Fig. 7F), about 560 um long and with a greatest depth ofabout 330 um, is elongate in lateral aspect. All the setae are long (more than the distanceci - d\), fine and slightly flexuose. Setae c\ and cj are inserted on the posterior margin of the collarand seta 2 submarginally. Vestigial f\ is located adjacent to seta h\ and towards the mid-dorsalline. The fissures ip and ips are absent. On each anal plate there are only three setae, of which adzis rather short. The chelicerae are about 172 um long. The principal segment carries 16- 19sharply pointed spines on the paraxial surface and 12-17 conical spines antiaxially. The legchaetotaxy is of the 'reduced type' with the setal formulae: I (1-3-2-5-15-1); II (1-3-2-3-11-1);III (2-2-1-2-10-1) and IV (2-1-0-2-9-1). On tarsus I seta u' is short, thick and resembles aeupathidium. TYPES: Holotype, BMNH reg. no. 1976.2.18.17, and two paratypes, 1976.2.18.18-19, from theF layer under a mixed stand of beech and oak, New Forest, Hampshire, 27.iii.73 (B. W. Parry).P. flexisetosus is known only from the type locality. B Fig. 8 Phthiracams globus: (A) notogaster, lateral; (B) sensillus and bothridium; (C) aspis,dorsal. THE GENUS PHTHIRACARUS 341 REMARKS: In comparison with the other 'reduced chaetotaxy' species examined, P.flexisetosusis rather large and the interlamellar and notogastral setae are much longer. Phthiracams globus sp. nov.(Figs 8; 9; PI. 4a) ADULT (PI. 4a): Large and moderately sclerotized. The aspis (Fig. 8C) ranges in length from324 - 365 um with a greatest width of 263 - 294 um. All the dorsal setae are moderately long andfine. Setae (//) are about 1-5 times the length of setae (la) and almost reach the level of the rostrals.The latter extend beyond the anterior margin of the aspis. The sensillus (Fig. 8B) is 50 - 60 umlong, lanceolate and serrated. It closely resembles that found in P. affinis. The notogaster (Fig.SA),578 - 852 um long and with a greatest depth of 426 - 553 um, is globular in lateral aspect. Allthe setae are long (more than the distance c\ - d\), fine and almost erect. Seta c$ is inserted on theposterior margin of the collar and setae ci_i submarginally. Vestigial f\ is located adjacent toseta h\ and towards the mid-dorsal line. In one paratype/i is located a short distance posterior toseta h\. The fissures ip and ips are absent. On each anal plate there are five long setae; an\-i andadj, being more or less equal in length and somewhat shorter than ad\-2. The chelicerae areapproximately 208 um long. The principal segment carries about 26 sharply pointed spines on theparaxial surface and about 24 conical spines antiaxially. The leg chaetotaxy is of the 'completetype' with the setal formulae: I (1-4-2-5-16-1); II (1-3-2-3-12-1); III (2-2-1-2-10-1) and Fig. 9 Phthiracarus globus : (A) leg I, trochanter to tibia, dorsal aspect ; (B) tarsus II, anterolateralaspect. 342 B. W. PARRY IV (2-1-1-2-10-1). Seta d on femur I is long, straight and only weakly serrated (Fig. 9A). Ontarsus II (Fig. 9B) seta//" is hooked distally. TYPES: Holotype, BMNH reg. no. 1976.2.18.3, from mosses and liverworts on rocks, RydalWater, Westmorland, 29.J.54 (P. N. Lawrence). Two paratypes, 1976.2.18.4-5, from mosses,Long Compton Woods, Warwickshire, 15.viii.51 (P. N. Lawrence). DISTRIBUTION: P. globus was also recorded in small numbers in the F and H layers under beechand oak at each of the study areas (see p. 324). Other material was examined from WythamWoods Estate, Berkshire, 28.ix.70 (T. G. Wood) and from Woodwalton Fen, Huntingdonshire,20.V.65 (P. N. Lawrence). REMARKS: Of the 'complete chaetotaxy' species examined, P. globus is somewhat unusual inbearing /i adjacent to h\, a feature generally associated with those species having the 'reducedchaetotaxy' combination. P. globus is similar to P. clavatus. However, in contrast to the latter, the sensillus of P. globusis lanceolate and the notogastral setae are distinctly procurved. Moreover, in P. globus vestigial/i is located much closer to the seta h\. Phthiracarus juvenalis sp. nov.(Fig. 10A-C; PI. 4b, d) ADULT (PI. 4b): Medium-sized and weakly sclerotized. The aspis (Fig. IOC) ranges in lengthfrom 258 - 279 jam with a greatest width of 213 - 223 urn. All the dorsal setae are moderatelylong and fine. Setae (/'/) are about 1-5 times the length of setae (la) and equal to the distance il-ro.The latter do not reach the anterior margin of the aspis. The sensillus (Fig. 10B; PI. 4d) is ratherlong (80 urn), narrow and pointed distally. The tracheoles are short and finger-like. The notogaster(Fig. 10A) ranges in length from 558 - 588 urn with a greatest depth of 365 - 406 urn. All thesetae are short (less than the distance c\ - d { ), fine and directed posteriorly. Setae c\ and c 3 areinserted close to the posterior margin of the collar and seta c 2 submarginally. Vestigial f\ islocated a short distance posterior to seta h\. The fissures ip and ips are absent. On each anal platethere are two setae in the anal series and one in the adanal series; all are moderately long andmore or less equal in length. The chelicerae are approximately 152 urn long. The principalsegment carries about 19 sharply pointed spines on the paraxial surface and about 15 conicalspines antiaxially. The leg chaetotaxy is of the 'complete type' with the setal formulae:I (1-4-2-5-16-1); II (1-3-2-3-12-1); III (2-2-1-2-10-1) and IV (2-1-1-2-10-1). TYPES: Holotype, BMNH reg. no. 1976.2.18.6, and one paratype, 1976.2.18.7, from leaf litter,Higher Kiln Quarry, Buckfastleigh, Devon, 25.iv.64 (C. Moreby). DISTRIBUTION: Common in mor forest soils. P. juvenalis was recorded under both the hard-wood and coniferous tree species at each of the study areas(see p. 324) being particularly abundantin beech and oak F where it accounted for 5-15% of the euptyctimoid population. Othermaterial was examined from Woodwalton Fen, Huntingdonshire, 20.V.65 (P. N. Lawrence) andfrom Castor Hanglands, Northamptonshire, 21.vi.63 (P. N. Lawrence). REMARKS: Of the species examined with a 'complete chaetotaxy', P. juvenalis is the only one topossess a rather long sensillus and backwardly directed notogastral setae. P. ligneus, recorded by Willmann (1932) in humus, moist Juncus and moss on the Dummersdorfbank, River Trave, West Germany, shows an overall similarity to P. juvenalis. The syntype series(five specimens mounted in Canada Balsam) has been examined, and in comparison to P. juvenalisthe specimens found to be much smaller (notogastral length 375 - 420 urn) while the notogastralsetae and the sensilli are distinctly longer than in P. juvenalis. P. juvenalis also resembles two recently described species, P. clemens Aoki 1963 from Tokyoand P. crispus Hammer 1972 from Tahiti. However, in comparison with P. juvenalis, topotypes ofP. clemens were found to be larger (notogastral length about 700 urn) while the holotype ofP. crispus was much smaller (notogastral length about 430 urn). Moreover, in contrast to P.juvenalis, the notogastral setae of both species are procurved. THE GENUS PHTHIRACARUS 343 Fig. 10A-C Phthiracarus juvenalis: (A) notogaster, lateral; (B) sensillus and bothridium; (C)aspis, dorsal. Fig. 10D-F Phthiracarus laevigatus: (D) notogaster, lateral; (E) sensillus and bothridium; (F)aspis, dorsal. 344 B. W. PARRY Phthiracarus laevigatus (C. L. Koch)(Fig. 10D-F; PI. 4e) Hoplophora laevigata Koch, 1841 : Fasc. 38 t.16; 1842 : 1 16. Phthiracarus laevigatus: Jacot, 1936 : 167; van der Hammen, 1963 : 704 (neotype designated). ADULT: Large and strongly sclerotized. The aspis (Fig. 10F) ranges in length from 406 - 456 umwith a greatest width of 355 - 400 um. All the dorsal setae are fine and short. Setae (//) are about1-5 times the length of setae (Id) and extend two-thirds of the distance il-ro. The sensillus (Fig.10E) is about 50 urn long, narrow and finely serrated. The notogaster (Fig. 10D) ranges in lengthfrom 812- 1065 urn with a greatest depth of 521 -771 urn, and in lateral view is seen to besharply angled at the level of seta c\ (PI. 4e). The latter is inserted relatively far back. All thesetae are short (less than the distance c\ - d\), fine and procurved. Vestigial f\ is located midwaybetween setae h\ and ps\. The fissures ip and ips are present. On each anal plate there are onlythree setae, an\-2 being much longer than ad$. The leg chaetotaxy is of the 'complete type' withthe setal formulae: 1(1-4-2-5-16-1); 11(1-3-2-3-12-1); 111(2-2-1-2-10-1) and IV(2-l-l-2-10-l). DISTRIBUTION : Three specimens only have been recorded in the British Isles from beech litter,Old Winchester Hill, Hampshire, 1971 (D. R. Kime). REMARKS : P. laevigatus is quite distinctive, being easily recognized by the marked angle of thenotogaster at the level of seta c\. The leg chaetotaxy is similar to that noted for the other 'com-plete chaetotaxy' species; on tarsus I the solenidion 0)2 is coupled with a small distal seta, afeature not mentioned by van der Hammen in his redescription. The British material has beencompared with the neotype from Regensburg - no morphological differences could be detected.P. brevisetae Jacot, described from decaying grass, Monroe, Connecticut, USA, appears to beclose to P. laevigatus. The holotype (slide no. 2534h) has been examined and found to be badlydamaged. Jacot's description (Jacot, 1930), however, agrees well with van der Hammen's (1963)and with the British material, but the attitude of the notogastral setae appears to differ slightly.In P. laevigatus the notogastral setae are procurved while in P. brevisetae they are directedposteriorly. Phthiracarus membranifer sp. nov.(Fig. 11A-C) ADULT: Small and weakly sclerotized. The aspis (Fig. 1 1C) ranges in length from 213 - 324 urnwith a greatest width of 157 - 243 urn. All the dorsal setae are fine and short. Setae (//) are about1-5 times the length of setae (Id) and extend two-thirds of the distance il-ro. The latter do notreach the anterior limit of the aspis. The sensillus (Fig. 1 IB) is 70 um long, narrow, membranousmarginally and reminiscent of that of P. juvenalis. The tracheoles are short and finger-like. Thenotogaster (Fig. 1 1 A) ranges in length from 314-517 um with a greatest depth of 223 - 324 um.All the setae are relatively long (equal to the distance c\ - d\), fine and almost erect. Setae c\ andcs are situated on the posterior margin of the collar and just anterior to seta 02- Vestigial f\ islocated a short distance posterior to seta h\. The fissures ip and ips are absent. On each anal platethere are only three setae; an\-2 being much longer than ad->,. The chelicerae are 116- 167 umlong. The principal segment carries 9-23 sharply pointed spines on the paraxial surface and8-20 conical spines antiaxially. The leg chaetotaxy is of the 'reduced type' with the setal formulae:I (1-3-2-5-15-1); II (1-3-2-3-11-1); III (2-2-1-2-10-1) and IV (2-1-0-2-9-1). On tarsus Iseta u' is short, thick and resembles a eupathidium. In one paratype the 'complete chaetotaxy'condition of tarsi I to IV (16, 12, 10 and 10) is associated with a 'reduced chaetotaxy' conditionon femur I (3) and genu IV (0). TYPES: Holotype, BMNH reg. no. 1976.2.18.14, and two paratypes, 1976.2.18.15-16, fromSitka spruce F, Tintern Forest, Monmouthshire, 4.vi.73 (B. W. Parry). DISTRIBUTION: P. membranifer was also recorded from Higher Kiln Quarry, Devon, 25.iv.64(C. Moreby) and from Torboll, Sutherland, 29.vi.76 (P. D. Hillyard). This species was notabundant in any of the samples examined. THE GENUS PHTHIRACARUS 345 A Fig. 11A-C Phthiracarus membranifer: (A) notogaster, lateral; (B) sensillus and bothridium;(C) aspis, dorsal. Fig. 11D-F Phthiracarus murphy /: (D) aspis, dorsal; (E) sensillus and bothridium; (F)notogaster, lateral. 346 B. W. PARRY REMARKS: The smallest of the British species examined, P. membranifer is somewhat unusualin bearing vestigial f\ posterior to the seta h\ (a feature generally associated with the larger'complete chaetotaxy' species). Phthiracarus murphyi Harding(Fig. 11D-F;P1. 4c) Phthiracarus murphyi Harding, 1976 : 164. ADULT (PI. 4c): Large and strongly sclerotized. The aspis (Fig. 1 ID) is about 300 um in lengthwith a greatest width of about 250 um. All the dorsal setae are fine and short. Setae (//) are about1-5 times the length of setae (la) and extend two-thirds of the distance il-ro. Setae (ro) do notreach the anterior limit of the aspis. The sensillus (Fig. HE) is short (40-50um), ovate andserrated. The notogaster (Fig. 11F) is about 700 um in length with a greatest depth of about420 um. All the setae are relatively long (equal to the distance c\ - d\) and markedly procurved.Seta C3 is inserted on the posterior collar margin and setae c\-2 submarginally. Vestigial /i islocated midway between setae h\ and ps\. The fissures ip and ips are present. On each anal platethere are five long setae; an 1-2 and adi being more or less equal in length and somewhat shorterthan adi-2. The chelicerae are approximately 213 um in length. The principal segment carriesabout 18 sharply pointed spines on the paraxial surface and about 16 conical spines antiaxially.The leg chaetotaxy is of the 'complete type' with the setal formulae: I (1-4-2-5-16-1); 11(1-3-2-3-12-1); III (2-2-1-2-10-1) and IV (2-1-1-2-10-1). On tarsus I the distal seta coupledwith solenidion 0)2 is rather short. Seta ft" on tarsus II is hooked distally. DISTRIBUTION: This species was collected in small numbers from Wytham Woods Estate,Berkshire, 28.X.70 (T. G. Wood) and from Torboll, Sutherland, 29.vi.76 (P. D. Hillyard). REMARKS : Although rather larger, P. murphyi appears to bear some resemblance to P. insularisJacot (notogastral length about 500 um) recorded from Teuanui, Tovii, the Marquesas Islands.Jacot (1935) did not refer in his description to the fissures ip and ips although his figure showsquite clearly that these fissures are present. In comparison with P. murphyi, the notogastral setaeof insularis appear to be shorter (less than the distance c\ - d\). Unfortunately, the 'cotype' ofP. insularis is apparently lost. Phthiracarus nitens (Nicolet)(Fig. 12A-C) Hoplophora nitens Nicolet, 1855 : 472. Phthiracarus nitens: van der Hammen, 1964 : 400 (neotype designated). ADULT: Large and moderately sclerotized. The aspis (Fig. 12B) ranges in length from 253-460 um with a greatest width of 213 - 360 um. All the dorsal setae are fine and short. Setae (//)are about 1-5 times the length of setae (la) and extend two-thirds of the distance il-ro. Thesensillus (Fig. 12A) is 50-60um in length, narrow and resembles that of P. laevigatus. Thenotogaster (Fig. 12C) ranges in length from 502 - 900 um with a greatest depth of 299 - 600 um.All the setae are short (less than the distance c\ - d\), fine and procurved. Seta c^ is inserted on theposterior margin of the collar and setae c\-2 submarginally. Vestigial/i is located midway betweensetae h\ and ps\. The fissures ip and ips are present. On each anal plate there are only three setae;an\-2 being much longer than adj. The chelicerae are approximately 270 um long. The principalsegment carries 17-21 sharply pointed spines on the paraxial surface and 10-19 conical spinesantiaxially. The leg chaetotaxy is of the 'complete type' with the setal formulae: I (1-4-2-5-16-1);II (1-3-2-3-12-1); III (2-2-1-2-10-1) and IV (2-1-1-2-10-1). On tarsus II seta/?" is hookeddistally. DISTRIBUTION: P. nitens was collected in small numbers from the following localities: WythamWoods Estate, Berkshire, 28.X.70 (T. G. Wood); St Agnes, Isles of Scilly, Cornwall, 5.iv.57(K. H. Hyatt); Higher Kiln Quarry, Devon, 25.iv.64 (C. Moreby); Tring Deer Park, Hertford-shire, l.ii.64 (P. N. Lawrence). THE GENUS PHTHIRACARUS 347 Fig. 12A-C Phthiracarusnitens: (A)sensillusand bothridium; (B)aspis, dorsal; (C) notogaster,lateral. Fig. 12D-F Phthiracarus rectisetosus: (D) aspis, dorsal; (E) sensillus and bothridium; (F)notogaster, lateral. 348 B. W. PARRY REMARKS: The neotype from Regensburg has been examined and in comparison with theBritish material the notogastral setae appear to be somewhat longer. The leg chaetotaxy is of the'complete type'. On tarsus I the solenidion 0)2 is coupled with a short distal seta and on tarus IIthe posterior fastigial seta is hooked distally. Neither of these features was noted by van derHammen in his redescription. P. nitens is similar to if not conspecific with P. montanus recorded by Perez-Ifiigo in grasslandsoil and moist moss, Sierra de Guadarrama, Spain. The holotype was examined and seen to becleared but undissected. In comparison with P. nitens, it differs only in the form of the distalregion of the sensillus which is lobular in montanus and pointed in nitens. Phthiracarus rectisetosus sp. nov.(Fig. 12D-F; PL 5c) ADULT (PI. 5c): Large and strongly sclerotized. The aspis (Fig. 12D) ranges in length from350 - 477 um with a greatest width of 268 - 360 um. All the dorsal setae are fine and short.Setae (//) which are inserted rather far forward and on a level with setae (Id) are about 1-5 timesthe length of the latter and extend two-thirds of the distance il-ro. Setae (ro) do not reach theanterior limit of the aspis. The sensillus (Fig. 12E) is 40 um long, ovate, serrated distally andresembles that found in P. murphyi. The notogaster (Fig. 12F) ranges in length from 710 - 994 umwith a greatest depth of 482 - 720 um. All the setae are relatively long (equal to the distanceci - di) and almost erect. Setae c\ and c$ are situated on the posterior margin of the collar andseta c^ submarginally. Vestigial f\ is located a short distance posterior to seta h\. The fissures ipand ips are present. On each anal plate there are five long setae; ai_2 and adi being more or lessequal in length and somewhat shorter than ad\-i. The chelicerae are 168 - 294 um long. Theprincipal segment carries 22 - 24 sharply pointed spines on the paraxial surface and 17-22 conicalspines antiaxially. The leg chaetotaxy is of the 'complete type' with the setal formulae: I(1-4-2-5-16-1); II (1-3-2-3-12-1); III (2-2-1-2-10-1) and IV (2-1-1-2-10-1). On tarsus I thedistal seta coupled with solenidion (02 is almost as long as the famulus. Seta/?" on tarsus II ishooked distally. TYPES: HOLOTYPE, BMNH reg. no. 1976.2.18.8, and one paratype, 1976.2.18.9, from beechlitter, Burnham Beeches, Buckinghamshire, 1964 (G. O. Evans). Two paratypes, 1976.2.18.10-11,from beech F, Wytham Woods Estate, Berkshire, 28.ix.70 (T. G. Wood). DISTRIBUTION: Common in mor soils particularly under beech. P. rectisetosus is evidentlywidely distributed in the British Isles and was abundant in all the samples examined from MonksWood, Cambridgeshire, 16.V.75 (J. A. MofFat); Woodbastwick Marshes, Norfolk, 10.vii.74(S. J. Moore); West Allendale, Northumberland, 18.ix.75 (R. M. Emberson); Long ComptonWoods, Warwickshire, 15.viii.51 (P. N. Lawrence); Hag Wood, Yorkshire, 12.iv.71 (D. R. Kime);Newtonmore, Inverness-shire, 3.vii.73 (M. J. Bishop); Lochdonhead and Tobermory, Mull,28.V.70 (P. N. Lawrence); Torboll, Sutherland, 29.vi.76 (P. D. Hillyard); Llanthony, Monmouth-shire, i.iv.73 (M. J. Bishop). REMARKS: P. rectisetosus bears some resemblance to two other 'complete chaetotaxy' species,namely P. clavatus and P. globus. However, P. rectisetosus bears four pairs of lateral fissures whileP. clavatus and P. globus bear only two pairs. Phthiracarus serrulatus sp. nov.(Fig. 13A-C; PI. 5b) ADULT (PI. 5b): Small and weakly sclerotized. The aspis (Fig. 13C) ranges in length from182- 213 um with a greatest width of 137- 157 um. All the dorsal setae are fine and short.Setae (//) are about 1-5 times the length of setae (la) and extend two-thirds of the distance il-ro.The rostrals which are inserted relatively far apart do not reach the anterior limit of the aspis.The sensillus (Fig. 13B) is long (70 um), narrow and tapers to a point distally with three or fourstraight-edged teeth subterminally. The tracheoles are short and finger-like. The notogaster(Fig. 13 A) ranges in length from 456 - 466 um with a greatest depth of 324 - 334 um. All the THE GENUS PHTHIRACARUS 349 Fig. 13A-C Phthiracarus serrulatus : (A) notogaster, lateral ; (B) sensillus and bothridium; (C)aspis, dorsal. Fig. 13D-F Phthiracarus tardus : (D) aspis, dorsal; (E) sensillus and bothridium; (F) notogaster,lateral. 350 B. W. PARRY Fig. 14 Phthiracarus tardus, anterolateral aspect of legs I, II and IV: (A) tarsus I; (B) leg I,trochanter to tibia; (C) tarsus II; (D) tarsus IV. (Fig. 14A-D are drawn at the samemagnification.) THE GENUS PHTHIRACARUS 351 setae are relatively long (equal to the distance ci - d\), fine and procurved. Seta c\ is inserted onthe posterior collar margin and setae ^2-3 submarginally. Vestigial f\ is located adjacent to seta h\and towards the mid-dorsal line. The fissures ip and ips are absent. On each anal plate there aretwo setae in the anal series and one in the adanal series - all are moderately long and more orless equal in length. The chelicerae are approximately 120 um long. The principal segment carriesabout 17 sharply pointed spines on the paraxial surface and about 16 conical spines antiaxially.The leg chaetotaxy is of the 'reduced type' with the setal formulae: I (1-3-2-5-15-1); II(1_3_2_3-11-1); III (2-2-1-2-10-1) and IV (2-1-0-2-9-1). TYPES: Holotype, BMNH reg. no. 1976.2.18.12, and one paratype, 1976.2.18.13, from beech F,Wytham Woods Estate, Berkshire, 28.ix.70 (T. G. Wood). P. serrulatus is only known from thetype locality. REMARKS: P. serrulatus shows an overall similarity to P. minimarginatus Woolley 1954, aspecies described from Colorado, USA. However, in comparison with serrulatus, the holotypeof minimarginatus (dissected, partially cleared and mounted in Berlese's fluid) was found topossess shorter notogastral setae while vestigial f\ was located midway between setae h\ andps\.Moreover, the sensillus of the American species was found to bear many more distal serrationsthan that of P. serrulatus. Both species are of a similar size (about 450 um). Phthiracarus tardus Forsslund(Figs 13D-F; 14; PL 5a, d) Phthiracarus tardus Forsslund, 1956 : 216. ADULT (PI. 5a): Small and weakly sclerotized. The aspis (Fig. 13D) is about 223 um in lengthwith a greatest width of about 187 um. All the dorsal setae are fine and short. Setae (//) are about1-5 times the length of setae (la) and extend two-thirds of the distance il-ro. The rostrals whichare inserted relatively far apart do not reach the anterior limit of the aspis. The sensillus (Fig. 13E;PI. 5d) is 30 - 40 um in length and broadly clavate. The notogaster (Fig. 13F) is about 497 um inlength with a greatest depth of about 314 um. All the setae are relatively long (equal to thedistance c\ - d\), fine and erect. Setae c\-i form a row just behind the posterior margin of thecollar. Vestigial f\ is located adjacent to seta hi and towards the mid-dorsal line. The fissures ipand ips are absent. On each anal plate there are only three setae; an\-i being much longer thanad$. The chelicerae are approximately 147 um long. The principal segment carries about 16sharply pointed spines on the paraxial surface and about 9 conical spines antiaxially. The legchaetotaxy (Fig. 14) is of the 'reduced type' with the setal formulae: I (1-3-2-5-15-1): II(l_3_2-3-12-l); III (2-2-1-2-10-1) and IV (2-1-0-2-9-1). On tarsus I seta u' is short, thick andresembles a eupathidium. Seta ft" on tarsus II is hooked distally and this segment carries asubunguinial seta s. DISTRIBUTION: Only a small number of specimens have been recorded in the British Isles frommull soil, Meathop Wood, Westmorland, 19.iii.63 (P. N. Lawrence). REMARKS: P. tardus is somewhat unusual in bearing 12 setae on tarsus II and by having ahooked posterior fastigial seta on this segment (both features are generally associated with'complete chaetotaxy' species).A comparison of British and paratype material revealed no morphological differences. 'Complete' and 'reduced' leg chaetotaxy a possible basis for a subdivision of the genus Phthiracarus The earliest proposed subdivision of the genus Phthiracarus appears to be that of Feider andSuciu (1957) who recognized two species groups based solely on the shape of the sensillus. Their'anonymum group' included species with spindle-shaped sensilli (anonymum, globosus, lanatus andpiger} and their 'lentulus group' species with thread-like sensilli (baloghi, italicus, lentulus, ligneus, 352 B. W. PARRY parabotrichus and sellnicki). However, these do not appear to be satisfactory groupings since thepresent study has suggested that sensillar shape is not correlated with other features, such as thechaetotactic pattern of the legs or notogaster. Eight years later and based on a study of three species, van der Hammen (1965) suggested thatthe number of notogastral fissures, the position of the vestigial seta f\ , the number of adanalsetae and the chaetotactic pattern of the legs were features which could be used in a futuresubdivision of the genus, and placed P. laevigatus and P. nitens (ip and ips present ; f\ ventral toh\; adi-2 absent; femur I with four setae; genu IV with a single seta) in a separate group fromP. anonymum (ip and ips absent ;/i dorsal to hi ; adi-2 present; femur I with three setae; genu IVwithout any setae). Although the number of adanal setae has been found to be uncorrelated withother morphological features, the present study supports van der Hammen's proposed divisionof the genus on the remaining characters. Of the eight British species having the combination'femur 1-4, genu IV-1', only murphy i and rectisetosus have all the attributes of van der Hammen's'laevigatus-nitens group', since the other species (qffinis, clavatus, globus and juvenalis) all lack thefissures ip and ips. In the case of species having the combination 'femur 1-3, genu IV-0', onlyP. anonymum possesses all the characters of van der Hammen's second grouping. Using numerical methods, Sheals (1969) examined the affinities of 19 Phthiracarus species fromEurope, Israel, Labrador and Morocco, recognizing three species groups based on the followingcombinations of characters: femur 1-4, genu IV-1, fissure ips present; femur 1-4, genu IV-1,fissure ips absent; femur 1-3, genu IV-0, fissure ips absent. It is noteworthy that P. anonymumwhich in the present study was found to be rather atypical, formed part of a reasonably compactcluster of five species in this grouping studied by Sheals (P. anonymum and four new species fromFrance, Labrador, Sweden and Switzerland). The evidence suggests therefore, that morphological differences, particularly in the legchaetotaxy, could provide a useful basis for dividing this large genus into two species groups.In the present study all the British species (and all the type specimens examined) fell into either a'complete' (affinis, clavatus, globus, juvenalis, laevigatus, murphyi, nitens and rectisetosus) or a'reduced chaetotaxy group' (anonymum, flexisetosus, membranifer, serrulatus and tardus). Inaddition to features of the leg chaetotaxy, a number of other characters were also used todistinguish between the two groupings. With the exception of P. affinis (notogastral length406 - 487 um), the species in the 'complete chaetotaxy group' are all rather large (notogastrallength 502 - 1065 um). Moreover, in this grouping, the vestigial seta f\ is generally ventral toseta h\ while on the aspis the rostral setae are always located rather close together. The fissuresip and ips are present in some members of the 'complete group' (laevigatus, murphyi, nitens andrectisetosus) while they are absent in affinis, clavatus, globus and juvenalis. By contrast, speciesin the 'reduced chaetotaxy group' are all relatively small (notogastral length 314 - 507 um), thefissures ip and ips are always absent, vestigial f\ is dorsal or slightly ventral to seta h\ and on theaspis the rostrals are often located relatively far apart. Any formal subdivision of the genus will, however, have to be deferred until a new type specieshas been designated. Van der Hammen (1965) considered P. contractilis (type) as being close tohis 'laevigatus-nitens group' (and thus to the 'complete chaetotaxy group'), but the type materialof P. contractilis must be presumed to be lost and Perty's original description is such as to makethe specific identity of his species impossible. Moreover, on the evidence available from thepresent study, P. anonymum would not be a suitable typical specimen of the 'reduced chaetotaxygroup'. Acknowledgements This paper is based substantially on part of a Ph.D. thesis (Parry, 1976) undertaken at theBMNH. The work was supervised jointly by Dr J. G. Sheals, Keeper of Zoology, BMNH, andby Dr J. A. Wallwork of the Zoology Department at Westfield College (University of London).Their valuable advice and encouragement are gratefully acknowledged. Thanks are also due tomy colleague, Mr D. Macfarlane, for his comments on the manuscript.Type material was kindly sent on loan by Dr J. Aoki, National University of Yokohama (NUY), THE GENUS PHTHIRACARUS 353 Dr L. van der Hammen, Rijksmuseum van Natuurlijke Historic (RNH), Leiden and by Dr C.Perez-Inigo, Institute Espanol de Entomologia (IEE), Madrid. Specimens from the Berlese andWillmann Collections were examined through the courtesy of Dr F. Pegazzano, IstitutoSperimentale per la Zoologie Agraria (ISZA), Florence, and Dr W. Hirschmann, Niirnbergrespectively. Dr R. E. Crabill, National Museum of Natural History (USNM), Washington,arranged for the loan of type material described by Ewing and Woolley, and Dr H. W. Levi,Museum of Comparative Zoology (MCZ), Cambridge, Massachusetts, allowed me to borrowthe type material of Bank's and Jacot's species. Dr J. Trave, Universite Pierre et Marie Curie(UPMC), Banyuls-sur-Mer, kindly provided topotypic material of Grandjean's species andDr S. L. Tuxen, University of Copenhagen Zoological Museum (UZM), sent type material ofspecies described by Marie Hammer. 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Soc. 48 : 232-267. 1935. Marquesan insects. II. Bull. Bernice P. Bishop Mus. 114 : 233-234. 1936. Les Phthiracaridae de Karl Ludwig Koch. Revue suisse Zool. 42 : 161-187. 1937. Six new mites from western North Carolina. Proc. ent. Soc. Wash. 39 : 163-166. 1938. More box-mites of the northeastern United States. // N. Y. ent. Soc. 46 : 109-139. 1939. New mites from western North Carolina. /. Elisha Mitchell scient. Soc. 55 : 197-202. 1946. On the validity of the genotypes designated by Koch (C. L.), 1837-1842, . . .. Bull. zool. Nom. 1: 161.Koch, C. L. 1836-1841. Deutschlands Crustaceen, Myriapoden und Arachniden. Regensburg. 1842. Vbersicht des Arachnidensy stems. Nurnberg. Krivolutsky, D. A. 1966. Some materials on the testaceous mites (Oribatei, Acariformes) from the environs of Blagoveschensk. Byull. mosk. Obshch. Ispyt. Prir. 71 : 125-129 (in Russian). 1975. See under Gilyarov, M. S. & Krivolutsky, D. A. 1975. [Contains first description of Phthira-carus ponticus Krivolutsky.]Macfadyen, A. 1952. The small arthropods of a Molinia fen at Cothill. /. anim. Ecol. 21 : 87-117. 1961. Improved funnel-type extractors for soil arthropods. /. anim. Ecol. 30 : 171-184 Michael, A. D. 1888. British Oribatidae, Vol. 2. London: Ray Society 1898. Oribatidae. Tierreich. 3 : 1-91. Murphy, P. W. 1954. Soil faunal investigations. Rep. Forest Res., Lond. (1953) : 110-116. Nicolet, H. 1855. Histoire naturelle des Acariens qui se trouvent aux environs de Paris. Archs Mus. Hist. nat. Paris 7 : 381-482.Oudemans, A. C. 1907. Nachtrag zur Milben-Fauna der Umgegend Bremens. Abh. naturw. Ver. Bremen 19 : 47-67. 1915. Overzicht der tot 1898 beschreven Phthiracaridae. Ent. Ber., Arnst. 4 : 212-220. Parry, B. W. 1976. On British euptyctimoid mites: a taxonomic and ecological study. Ph.D. Thesis, Unversity of London.- 1978. A new species of Steganacarus (Acari, Cryptostigmata) from Israel. Bull. Br. Mus. nat. Hist. (Zool.) 33 (4) : 279-285. Perez-Inigo, C. 1969. Nuevos oribatidos de suelos espanoles (Acari, Oribatei). Eos. Madr. 44 : 377-403.Perty, M. 1839. Isis, Jena 23, Hft. 11 and 12: column 847.1841. Allgemeine Naturgeschichte, als Philosophische und Humanitdtswissenschaft fur Naturforscher, Philosophen und das hoher gebildete Publikum. Vol. 3. Bern.Ramsay, G. W. 1966. Three new box-mites (Acari : Oribatei : Phthiracaroidea) from the Brothers, Cook Strait, New Zealand. N.Z. Jl Sci. 9 : 901-912. THE GENUS PHTHIRACARUS 355 Scopoli, J. A. 1763. Entomologia carniolica exhibens insecta Carnioliae indigena et distributa in or dines, genera, species, varietates. Vindobonae. Sellnick, M. 1960. Formenkreis: Hornmilben, Oribatei. Tierwelt Mitteleur. 3 : 45-132.Sheals, J. G. 1965. Primitive cryptostigmatid mites from rhododendron forests in the Nepal Himalaya. Bull. Br. Mus. nat. Hist. (Zool.) 13 : 1-35. 1969. Computers in acarine taxonomy. Acarologia 11 : 376-396. Sikorski, J., Notts, J. A., Moss, J. S. & Buckley, T. 1967. A new preparation technique for examination of polymers in the scanning electron microscope. Proc. R. microsc. Soc. 2 : 431-432.Tragardh, I. 1910. Acariden aus dem Sarekgebirge. Naturw. Unters. Sarekgebirg. 44 : 27-585.Turk, F. A. 1953. A synonymic catalogue of British Acari. II. Ann. Mag. nat. Hist. 6 : 81-99.Willmann, C. 1923. Oribatiden aus Quellmoosen. Arch. Hydrobiol. 14 : 470-477.1928. Die Oribatidenfauna nordwestdeutscher und einiger siiddeutscher Moore. Abh. naturw. Ver. Bremen 27 : 143-176. 1931. Moosmilben oder Oribatiden (Cryptostigmata). Tierwelt Dtl. 22 : 79-200. 1932. Die Oribatiden des Dummersdorfer Ufers (Untertrave). In DasLinke Untertraveufer (Dummers- dorfer Ufer), pp. 422-443, Lubeck: Denkmalrat.1939. Die Arthropodenfauna von Madiera nach den Ergebnissen der Reise von Prof. Dr. O. Lundblad Juli - August 1935. XIV. Terrestrische Acari (exkl. Ixodidae). Ark. Zool. 31A (10) : 1-42.1951. Untersuchungen iiber die terrestrische Milbenfauna im pannonischen Klimagebiet Osterreichs. Sber. ost. Akad. Wiss. 160 : 91-176.Woolley, T. A. 1954. A new species of box-mite from Colorado (Oribatei : Phthiracaridae). Am. Midi.Nat. 52 : 197-200. Appendix 1 Species described between 1763 and 1977 currently classified in Phthiracarus Species Date Type habitat and locality Type depository* Hoploderma affine Hull f 1914 Phthiracarus anonymum 1933 Grandjeanf Phthiracarus anonymus 1938 amicus Jacotf Phthiracarus apiculatus Jacot 1939 Phthiracarus baloghi Feider 1957 & Suciu Phthiracarus benoiti Balogh 1958 Hoploderma boreale 1910 Tragardhf Phthiracarus boresetosum 1930 Jacot f Phthiracarus brevisetae 1930 Jacot f Phthiracarus caudatus 1977 Balogh & Mahunka Phthiracarus clemens Aokif 1963 Phthiracarus compressum 1930 Jacotf Phthiracarus contractilis 1841 Pertyt Phthiracarus crenophilus 1951 Willmannf Moss in woods and Sphagnum on moors, West Allendale, Northumberland and Gibside, Durham, England Rotting wood in cellar, Perigueux, Dordogne, France Deciduous leaf mould, Connecticut Hill, New York, USA Oak litter in old growth stand, Bent Creek Exp. Forest, North Carolina, USA Oak leaves, Iai, Rumania Angola Rotting birch leaves, Sarek, Swedish Lapland Haircap moss in woodland, Cliff Island, Casco Bay, Maine, USA Decaying grass at foot of old haystack, East Village, Monroe, Connecticut, USA Moist soil in virgin forest, Estancia Esperanza, Guayaramerin, Bolivia Imperial Palace Gardens, Tokyo, Japan Upland swamp Sphagnum, East Village, Monroe, Connecticut, USA Rotting wood, Munich, Augsberg and Passau, West Germany Edge of marsh, Ebreichsdorf, Austria BMNH, London UPMC, Banyuls-sur Mer [Topotype] MCZ, Cambridge, Mass. [Type series apparentlylost] Unknown TM, Budapest BMNH, London ['Cotype'] MCZ, Cambridge, Mass. MCZ, Cambridge, Mass. TM, Budapest NUY, Yokohama [badly broken] MCZ, Cambridge, Mass. [Type series apparentlylost] Hirschmann Coll.,Niirnberg 356 B. W. PARRY Species Date Type habitat and locality Type depository* Hoplophora crinita Koch 1841 Phthiracarus crispus 1 972 Hammerf Phthiracarus curtulus 1923 Berleset Phthiracarus danubianus 1 968 Feider, Vasilu & Calugar Oribates dasypus Duges t 1 834 Phthiracarus dubinini 1958 Feider & Suciu Phthiracarus f eider i \ 963 Balogh & Csiszar Hoplophora ferruginea Koch 1841 Phthiracarus globifer 1 962 Hammerf Hoplophora globosa Koch 1 84 1 Phthiracarus hamatus 1 973 Hammerf Phthiracarus insularis Balogh 1962 Phthiracarus insularis Jacot 1935 Hoploderma italicum 1907 Oudemans^: ( = Oribates dasypus Duges sensu Berlese) Phthiracarus jacoti Feider & 1958 Suciu Phthiracarus japonicus 1 958 Aokif Hoplophora laevigata Kochf 1841 Phthiracarus lanatus 1957 Feider & Suciu Hoplophora lentula Koch 1841 Phthiracarus ligneusWillmannf 1932 Hoplophora longula Koch 1841 Hoplophora lucida Koch 1841 Hoploderma lurida Ewingf 1909 Phthiracarus machadoi Balogh 1958 Phthiracarus minimarginatus 1954Woolleyf Phthiracarus montanus 1 969 Perez-Inigof Phthiracarus montium Jacot 1937 Moss in woods, Regensburg area, West Germany Rotting leaves and moss (altitude 600 m), Papeete, Tahiti Lake City, Florida, USA Moss and leaves, Cazanele Mici, Rumania Ardennes, France Hornbeam litter, Constanta, Rumania Litter and moss on bark in marsh forest, Rio Negro, El Bolson, Argentina Moss on trees, Regensburg area, West Germany Meadow near river, Copiapo, Chile Damp meadows, Regensburg area, West Germany Dry bark on deciduous tree, Tongatapu Island La Mandraka, Madagascar Dead leaves, Teuanui, Tovii (altitude 2000 ft), Marquesas Islands Tiarno, Italy Spruce and fir needles Brasov, Rumania Raw humus under conifers, Matsumoto, Japan Clubmosses and soil under hedges and bushes, Regensburg area, West Germany Moss, Odorhei, Mures-Magyar, Rumania Moss in woods, Regensburg area, West Germany Humus, moist Juncus and moss on the Dummersdorf bank, River Trave, West Germany Moss in forests, Regensburg area, West Germany Marshy places in meadows, Regensburg area, West Germany Under bark, Urbana, Illinois, USA Angola Moss and grass under aspen, Mount Meeker Camp Ground, Boulder, Colorado, USA Grassland soil and moist moss, Sierra de Guadarrama, Spain Litter in short-leaf pine stand, Ashville, North Carolina, USA [Type series apparently lost] UZM, Copenhagen ISZA, FlorenceUnknown [Type series apparently lost] Unknown TM, Budapest [Type series apparently lost] UZM, Copenhagen [Type series apparently lost] UZM, Copenhagen TM, Budapest [Type series apparently lost] ISZA, Florence Unknown NUY, Yokohama [badly broken] RNH, Leiden [Neotype] Unknown [Type series apparentlylost] Hirschmann Coll.,Nurnberg [Type series apparently lost] [Type series apparently lost] USNM, Washington TM, Budapest USNM, Washington IEE, Madrid [Type series apparentlylost] THE GENUS PHTHIRACARUS 357 Species Date Type habitat and locality Type depository* Phthiracarus murphy i 1976 Hardingf Phthiracarus nigerrimus 1 920 Berlesef Hoplophora nitens Nicoletf 1855 Phthiracarus olivaceus 1928 Jacotf Phthiracarus pallidus 1 958 Feider & Suciu Phthiracarus parabotrichus 1957 Feider & Suciu Phthiracarus pavidus minus 1966 Krivolutsky Phthiracarus pellucidus 1 966 Ramsay Phthiracarus peristomaticus 1 95 1Willmann^ Acarus piger Scopolit 1763 Phthiracarus ponticus 1975 Krivolutsky Phthiracarus prior Jacot 1933 Phthiracarus pudicus 1923 Berlesef Phthiracarus pygmaeus Balogh 1958 Phthiracarus restrict us 1937 Jacot Phthiracarus robertsi 1965 Shealsf Phthiracarus rotundus 1923 Berlesef Phthiracarus roubali Berlesef 1923 Phthiracarus sarahae Jacot f 1930 19571977 Phthiracarus sellnickiFeider & SuciuPhthiracarus serrulaBalogh & Mahunka Phthiracatus setanus 1939 Jacot Hoplophora setosa Banksf 1 895 Phthiracarus setosellum 1928 Jacot f Phthiracarus setosellum 1 930 bryobium Jacot * Phthiracarus sicilicoma 1 962 Hammerf Hoplophora sphaerula 1 895 Banks:): Beech litter, Lambridge Wood,Oxfordshire, EnglandLa Plata, Argentina BMNH, LondonISZA, Florence Litter in woods near Paris, France RNH, Leiden [Neotype]Soft moist soil, East Village, Monroe, MCZ, Cambridge, Mass.Connecticut, USABeech litter, lasi, Rumania Unknown Leaves, lasi and Constanta,RumaniaBlagoveschensk, USSR Halophytic scrub and mat plants, Little Brother Island, Cook Strait, New Zealand Number of habitats including leaves, turf and subsoil under buckthorn, guelder-rose and alder, near Vienna, Austria Encrusting lichens, Carniola ('Karniolie'), Yugoslavia Unknown Gainesville and East Palatka, Florida, USA Cape of Good Hope, South Africa UnknownUnknown DS1R, Nelson & BMNH,London [Type series apparentlylost] [Type series apparently lost] Unknown [Type series apparently lost] ISZA, Florence Angola TM, Budapest Litter in rocky cove, Bent Creek Exp. [Type series apparently Forest, North Carolina, USA lost] Rhododendron litter, Milke Danra, BMNH, London Nepal Citta di Castello, Italy ISZA, Florence 'Boemia (Brady)', possibly Czechoslovakia Spruce needles, Cliff Island, Casco Bay, Maine, USA Conifer needles, Brasov and Ploiesti, Rumania Gallery forest along River Mamore, Estancia Esperanza, Guayaramerin, Bolivia Litter in laurel slick, Bent Creek, Exp. Forest, North Carolina, USA Sea Cliff, New York, USA Rotten wood and bark slabs, Glen Cove, Long Island, New York, USA Upland swamp moss, East Village, Monroe, Connecticut, USA Meadowy vegetation under trees, Puerto Montt, Chile Sea Cliff, New York, USA ISZA, Florence MCZ, Cambridge, Mass. Unknown TM, Budapest [Type series apparently lost] MCZ, Cambridge, Mass. MCZ, Cambridge, Mass. MCZ, Cambridge, MassUZM, Copenhagen [Type series apparentlylost] 358 B. W. PARRY Species Date Type habitat and locality Type depository* Hoplophora straminea Koch 1841 Moss on trees, Regensburg area, [Type series apparently West Germany lost] Phthiracarus subglobosus 1923 Vallombrosa, Italy ISZA, Florence Berlesef Phthiracarus tardus 1956 Humus under Vaccinium in NR, Stockholm & BMNH, Forsslundf coniferous forest, Degerfors, London [Paratype] Vasterbotten, Sweden Hoplophora testudinea Koch 1841 Moss on trees, Regensburg area, [Type series apparently West Germany lost] Phthiracarus torosus 1939 Leaves, Levado do Inferno, Madeira [Type series apparently Willmann lost] Phthiracarus tubulus 1972 Cyperus litter near coast, Tahiti UZM, Copenhagen Hammerf ( = lapsus calami for Hoplophthiracarus tubulus) Phthiracarus undatus 1915 Paris area, France [Type series apparently Oudemans^ lost] * With the following exceptions, DSIR (Department of Scientific and Industrial Research), Nelson, NR(Naturhistoriska Riksmuseet), Stockholm, and TM (Termeszettudomanyi Muzeum), Budapest, explana-tions of depository abbreviations are given with the Acknowledgements. t Specimens examined during the course of the present study,t Species regarded as nomina dubia. THE GENUS PHTHIRACARUS 359 Plate 1 Phthiracarus affinis: idiosomal and gnathosomal features, (a) Sensillus and bothridialscale, x2400. (b) Aggenital seta in furrow of genital plate, anterior aspect, x 1300. (c) Adoralsetae and rutella, ventral aspect, x!300. (d) Terminal segment of pedipalp showing reducedsubultimal seta, x 1450. (e) Sensillar notch and thickened bothridial aperture, x 1500. 360 B. W. PARRY Plate 2 Phthiracarus affinis: legs, (a) Tarsus I, anterolateral aspect, x 1 100. (b) Distal solenidionand associated seta on tarsus I, posterolateral aspect, x 5100. (c) Proximal region of tarsal claw,anterolateral aspect, x!700. (d) Dorsal seta on femur I, x4800. (e) Solenidion and associatedseta on tibia II, anterolateral aspect, x2400; dorsal aspect, x 15 000 (shown in inset). THE GENUS PHTHIRACARUS 361 Plate 3 Phthiracams spp. : (a) P. affinis, lateral aspect, x60; (b) P. anonymum, lateral aspect,x 130; (c) P. clavatus, lateral aspect, x 100; (d) sensillus of P. a f finis, x 1 500; (e) P. anonymum,ventral aspect, x!20; (f) sensillus of P. clavatus, x!900. 362 B. W. PARRY Plate 4 Phthiracarus spp. : (a) P. globus, x!50; (b) P. juvenalis, x80; (c) P. murphyi, x60;(d) sensillus of P. juvenalis, x600; (e) P. laevigatus, x 350. All mites shown in lateral aspect. THE GENUS PHTHIRACARUS 363 Plate 5 Phthiracarus spp. : (a) P. tardus, lateral aspect, x 100; (b) P. serrulatus, anterior aspect,x200; (c) P. rectisetosus, lateral aspect, x60; (d) sensillus of P. tardus, x2600. Manuscript accepted for publication 3 May 1978 British Museum (Natural History)Monographs & Handbooks The Museum publishes some 10-12 new titles each year on subjectsincluding zoology, botany, palaeontology and mineralogy.Besides being important reference works, many, particularly amongthe handbooks, are useful for courses and students' backgroundreading. Lists are available free on request to : Publications Sales British Museum (Natural History) Cromwell Road London SW7 5BD Standing orders placed by educational institutions earn a discountof 10% off our published price. Titles to be published in Volume 35 A revision of the 'acaecate' earthworms of the Pheretima group(Megascolecidae: Oligochaeta) : Archipheretima, Metapheretima,Planapheretima, Pleionogaster and Polypheretima. By E. G. Easton. Miscellanea The planktonic copepods of the northeastern Atlantic Ocean:Harpacticoida, Siphonostomatoida and Mormonilloida. By G. A.Boxshall. Towards a phyletic classification of the 'genus' Haplochromis (Pisces,Cichlidae) and related taxa. Part I. By Peter Humphry Greenwood. A revision of the British species of the genus Phthiracarus Perty, 1841(Cryptostigmata: Euptyctima). By B. W. Parry. Printed by Henry Ling Ltd, Dorchester