Some Digenetic Trematodes from Fishes of New Zealand*Studies from the Department of Zoology, University of Nebraska, NO. 270.

Transactions and Proceedings of the Royal Society of New Zealand, Volume 82, 1954-55, Page 475

Some Digenetic Trematodes from Fishes of New Zealand*Studies from the Department of Zoology, University of Nebraska, NO. 270. By Harold W. Manter, University of Nebraska. [Communicated by L. R. Richardson, and read before a meeting of the Wellington Branch, February 17, 1954; received by the Editor. February 21, 1954.] Abstract. Sixty-Six species of digenetic trematodes are recorded from 58 species of New Zealand fishes. Thirty-eight new species and six new genera (five of them based on New Zealand species) are named. Comparative studies lead to the reduction of 11 previously named species as synonyms, and 9 new names are proposed as new combinations. A tendency toward host specificity of these trematodes is seen in that 56 species, or about 80% of the total, were collected from single species of host, and only three species, all Hemiundae, were found in five or more species of host. Some affinities are noted to trematodes of fishes of the Northern Hemisphere. Of the 25 species previously known outside of New Zealand: 17 species occur also in either the North Atlantic or the North Pacific; 11 species in the North Atlantic (9 being known only from there); 9 in the North Pacific (6 being known only from there); 7 in Australia or Tasmania, 3 in the Celebes. Several species of the cold water South Pacific are common in fishes of deep water in the Gulf of Mexico suggesting that a continuous distribution may occur by way of the deep sea. The fish hosts differ in the different regions. Derogenes varicus is a common trematode of New Zealand as it is in many fishes of the Northern Hemisphere and in deep sea fishes, although it is absent in warm seas. On the other hand, six of the eight trematodes of the conger eel, a fish of both hemispheres, are not known in the north. Keys are given to species of seven genera (Decemtestis; Genolinea; Opecoelus; Plagioporus [subgenus Plagioporus]; Pseudopecoelus; Tergestia and Tubulovesicula). A host-parasite list is given. Table Of Contents Pages INTRODUCTION 477 TREMATODES COLLECTED Aspidogastridae 1. Macraspis elegans, Olsson, 1869 480 Bucephalidae 2. Telorhynchus arripidis Crowcroft, 1947 482 3. Alcicornis longicornutus n.sp. 482 4. Dolichoenterum longissimum Ozaki, 1924 483 Opistholebetidae 5 Choanomyzus lasmaniae Manter and Crowcroft, 1950 484 Lepocreadiidae 6. Lepidapedon congeri n.sp. 484 7. Lepidapedon ausralis n.sp. 485 8 Neolepidapedon polyprioni n. gen., n.sp. 486 9 Neolepidapedon cablei n.sp. 489 10. Proenenterum isocotylum n.gen., n.sp. 490 11. Proenenterum ericotylum n.sp. 491 12. Holorchis pulcher n.sp. 492 13. Myzoxenus crowcrofti n.sp 495 14. Pancreadium otagoensis n.gen, n.sp. 496 15. Pseudocreadium monacanthi Layman, 1930 498 16. Stegodexamene anguillae Macfarlane. 1951 498

Acanthocolpidae 17. Stephanostomum pristis (Delongschamps, 1824) Looss, 1899 498 18. Stephanostomum australis n.sp. 499 Opecoelidae 19. Opecoelus lotellae n. sp. 500 20. Opegaster gobii Yamaguti, 1952 503 21. Opegaster caulopsettae n. sp. 503 22. Pseudopecoelus tulgaris (Manter, 1934) von Wicklen, 1946 23. Pseudopecoelus hemilobatus n. sp. 505 24. Pseudopecoelus japonicus (Yamaguti, 1938) von Wicklen, 1946 507 25. Pseudopecoelus tenuis Yamaguti, 1940 509 26. Plagriporus preporatus n.sp. 509 27. Plagioporus dactylopagri n. sp. 510 28. Plagioporus interruptus n.sp. 511 29. Plagioporus (Caudotestis) pachysomus nsp. 512 30. Podocotyle caithnessi n.sp. 517 31. Helicometra grandora n.sp. 518 32. Coitocaecum tylogonium n.sp. 518 33. Coitocaecum anaspidis Hickman, 1934 520 34. Decemtestis pseudolabri n.sp. 521 35. Brevicreadium congeri n.gen., n.sp. 523 Fellodistomatidae 36. Benthotrema richardsoni n.sp. 524 37. Tergestia agnostomi n.sp. 526 38. Steringotrema rotundum n.sp. 527 39. Proctoeces subtenue (Linton, 1907) Hanson, 1950 528 Steganodermatidae 40. Deretrema minutum n.sp. 530 Heterophyidae 41. Telogaster opisthorchis Macfailane, 1945 532 Gorgoderidae 42. Problitrema philippi Woolcock, 1935 532 43. Problitrema clelandi Johnston, 1934 533 Accacoeliidae 44 Odhnerium calyptrocotyle (Monticelli, 1893) Yamaguti, 1934 533 Bivesiculidae 45. Bivesiculoides otagoensis n.sp. 533 Ptychogonimidae 46. Ptychogonimus megastoma (Rudolphi, 1819) Lühe, 1900 534 Syncoeliidae 47 Syncoelium thyrsitae (Crowcroft, 1948) Yamaguti, 1953 535 Hemiuridae 48. Ectenurus lepidus Looss, 1907 536 49 Lecithochirium genyplen n.sp. 536 50 Lecithochirium flexum n.sp. 538 51. Lecithochirium conviva Lühe, 1901 539 52 Lecithochirium australis n.sp. 541 53. Tricotyledonia genypleri Fyfe, 1954 542 54. Lecithocladium excisum (Rudolph, 1819) Lühe, 1901 542 55 Lecithocladium magnacetabulum Yamaguti, 1934 542 56 Lecithocladium seriolellae n.sp. 543 57 Tubulovesicula angusticauda (Nicoll, 1914) Yamaguti. 1934 545 58. Stcrrhurus lotellae n.sp. 545 59. Derogenes varicus (Müller 1784) Looss, 1901 548 60 Derogenes nototheniae n.sp. 548 61 Mitrostoma nototheniae n.gen, n.sp. 550

62. Gonocerca phycidis Manter, 1925 551 63. Genolinea anura (Layman, 1930) Yamaguti. 1934 552 64. Genolinea dactylopagri n. sp. 553 Aporocotylidae 65. Cardicola coridodacis n.sp. 554 66. Cardicola whitteni n.sp. 557 Host-Parasite List 558 Discussion 559 Summary 562 References 565 Introduction. The following report is based on collections made by the author during March to August, 1951, while in New Zealand as a Fulbright Research Scholar. He was associated with the Zoology Department, Victoria University College, Wellington, and most of the collecting was done at Wellington. Effort was made to secure as wide a variety of fishes, particularly marine species, as possible. Since no organised ichthyological surveys were in progress, the chief source of material was from commercial fishermen. In July, two weeks were spent at the Portobello Biological Station near Dunedin. Acknowledgments: Whole-hearted co-operation was extended by the United States Educational Foundation in New Zealand for all general arrangements; by Victoria University College for use of facilities and equipment; and by Otago University for facilities at the Portobello Laboratory. During work of this character, one becomes indebted to many individuals for various kinds of aid and encouragement. Professor L. R. Richardson of Victoria University College showed constant interest in the work and gave helpful aid and advice. Mr. T. Caithness, fishmonger at Karori (Wellington) was of indispensible help in arranging for supplies of fishes from fishermen who frequently troubled themselves to bring in fishes of no commercial. value Since fishes in New Zealand are customarily cleaned at sea, special arrangements were necessary in order that some specimens be delivered intact. The Fisheries Research Laboratory also furnished a number of specimens, particularly eels and Galaxias. Others to whom the author is indebted include Lloyd Whitten, Parasitologist, Animal Research Station, Wallaceville; Captain J. Black, Dunedin; Mr. Jack Garrick, Victoria University College; C. A. McCann, Dominion Museum, Wellington; Marion L. Fyfe and L. O. Simpson, Otago University. Historical: Relatively few trematodes have been collected from marine fishes of southern seas. Leiper and Atkinson (1914, 1915) report five species collected near Cape Evans (77° 38′ S) from a single species of fish, Trematomus bernacchii, of which about 300 specimens were examined. All five trematodes were named as new species. It should perhaps be noted that the generic disposition of these specie; is rather unsatisfactory, viz.: (1) Hemiurus oatesi does not belong in the genus Hemiurus because of the character of the thick-walled, elongate seminal vesicle which is of the form characteristic of Lecithocladium or Parahemiurus. This species is considered as Parahemiurus oatesi (Leiper & Atkinson, 1914) n. comb. related to P. australis Woolcock, 1935 and P. lovettiae Crowcroft, 1947, differing in more symmetrical testes and larger eggs. (2) Aponurus bowersi

cannot belong in the genus Aponurus because the vitellaria consist of two compact, almost tandem, lobes rather than seven. The authors do not describe the seminal vesicle or any of the terminal genital ducts except a “cirrus,” hence the generic disposition of this species must remain uncertain; it could be Derogenes or Genolinea. (3) Lepodora garrardi, later known as Lepidapedon garrardi, is an uncertain member of that genus as noted by Hanson (1950, p. 81). (4) Podocotyle pennelli could not be included in Park's (1937) key because of incomplete description. (5) Allocreadium fowleri was based on immature specimens actually insufficient for generic allocation. They almost certianly do not belong in the genus Allocreadium. Szidat (1950) has recently reported six species of trematodes from Eleginops maclovinus from Tierra del Fuego. Three of these were new species; the other three identified only to genus. T. H. Johnston and William Nicoll have each reported a few Digenea from Australia. More recently Peter Crowcroft (1945–1950) has found a number of interesting species in Tasmania. Few trematodes have been reported from New Zealand. Most of these have been introduced species (Young, 1938). Macfarlane (1939) notes that the 30 species of Digenea listed from New Zealand by Hutton (1904) were apparently inferred from the presence of introduced hosts and were not actually collected, As early as 1903, Haswell reported two kinds of sporocysts in Mytilus latus on the New Zealand coast. Recently Macfarlane has described several species of Digenea from New Zealand fishes and has also made some ecological and life cycle studies (Macfarlane, 1939, 1945, 1951, 1952). Telogaster opisthorchis Macfarlane, 1945 and Stegodexamene anguillae Macfarlane, 1951 occur in New Zealand eels. Coitocaecum anaspidis Hickman, 1934 occurs in Galaxias brevipennis, G. attentuatus, Gobiomorphus gobioides, and in small Anguilla species. Metacercariae of this species in an amphipod, Paracalliope fluviatilis, are often progenetic. C. anaspidis is of interest in that it also occurs in freshwater streams of Tasmania where it is apparently always progenetic in amphipods, omitting the fish host altogether. It has not as yet been reported from Australia or South America. Fyfe (1953) describes Otodistomum plnnketi from Scymnodon plunketi, and at the time of this writing has in press the description of a new hemiurid genus. Tricotyledonia, related to Lecithochirium, from Genypterus blacodes. The literature on trematodes of fishes is very widely scattered and much of it is difficult to secure. Dawes has published two very useful books, one (1946) dealing with Trematoda in general and one (1947) dealing with trematodes of British fishes. Neither of these volumes includes many species other than those of European waters. Thus, the recent compilation by Yamaguti (1953a) “Systema Helminthum. Part I. Digenetic Trematodes of Fishes” is of great value. This volume appeared after the text of this paper was completed. It is generously illustrated and includes keys to, and descriptions of, 367 genera of trematodes together with a list of species in each genus. It is the only modem comprehensive treatment of these common parasites of fishes. Sources Of Material: Most of the fishes brought to the Karori fish market are dredged from depths up to 80 fathoms near Point Campbell on the south side of Cook Strait. Not far from this area is fairly deep water from which there is probably some upwelling. At any rate, a deepwater influence is seen in the

prevalence of Macrouridae (“rat, tails”) and may also explain the occurrence of several species of trematodes known from fairly deep water of the Northern Hemisphere. However, there is reason to believe that at least some such deep water species of trematodes occur in more shallow water hosts in colder seas although absent from shallow water of warm seas (Manter, 1934, 1947). Techniques: No new methods of technique were employed. Trematodes must be collected by washing away the content of the digestive tract; scraping the wall deeply; then allowing the mixture to settle in a container of suitable size, and decanting until only the heavier particles remain. This material is to be examined by the naked eye, by hand lens or magnifier, and if possible by dissecting microscope for detection of the smallest species. After some experience, one can recognize even small specimens by use of a good hand lens. Trematodes were killed in formol-acetic-alcohol (FAA) solution under slight pressure of a coverglass, care being taken to exert no more pressure than necessary to keep the specimen in a moderately extended condition. Some species require no pressure at all, while a few of the muscular hemiurids require use of a slide for pressure. This method of killing has been criticised as causing distortion, and techniques involving shaking, hot killing solutions, or anesthetizing chemicals have been recommended. Such other methods apparently are successful with some species but at the present time it is still my opinion, particularly if few specimens are available, that the pressure method carefully used is most certain to furnish good material for study. It is almost impossible to study badly contracted, curled, or bent specimens. Specimens were stained with Delafield's haematoxylin because it is rapid, easily controlled, and gives satisfactory differentiation especially with recently preserved material. Carmine stains give brilliant mounts of trematodes and are widely used, but they require more exact manipulations. General Results: A total of 66 species of digenetic trematodes, distributed in 16 families, were collected from 58 species of fishes. The fishes examined represented 42 families. Thus, although the survey cannot be considered more than preliminary, it was of broad scope and the yield of more than one species of trematode per species of fish is relatively high considering the number of individuals examined. In the case of 14 species only a single host was examined. and in 9 others only two were examined. Thus, the list of trematodes reported here must be far from complete even for the hosts listed and many species of New Zealand fishes were not collected. Northern New Zealand which was not sampled at all is likely to have numerous trematodes not found further south. It will be interesting to know how much tropical influence might have reached to northern New Zealand. The trematodes of fishes of warm seas tend to be distinct from those of cooler waters. Of the 66 species of Digenea collected. 38, or more than half, were considered to be new, including five new genera. Disposition Of Type Specimens: Holotype specimens of all new species are deposited in the Helminthological Collection of the United States National Museum. Paratypes have been sent to the Zoology Department, Victoria University College, Wellington. Remaining paratypes are in the author's collection.

Specimens of most of the species identified as already named have also been deposited in the United States National Museum. When the supply was sufficient, similar slides have been sent to Victoria University College. Order Aspidogastrea Family Aspidogastridae. 1. Macraspis elegans Olsson, 1869. (Fig. 1) Host: Callorhynchus milii Bory, elephant fish; gall bladder. Localities: Wellington, Portobello. Specimen Deposited: U.S. Nat. Mus. Helminth. Collection No. 49154. Discussion: This aspidogastrid is one which undergoes great growth accompanied by great changes in body proportions. The trematode is also highly muscular. Because of resulting variations it does not seem possible to separate the New Zealand species from the North Atlantic Macraspis elegans from Chimaera monstrosa. The most complete description is by Jägerskiöld (1899) who described specimens varying from a length of 1.25 mm. with about 10 sucking grooves or acetabula to 15 mm. with “nearly” 100. Living worms are reddish in colour, the pigment being in the lateral parts of the ventral disc. Usually two specimens occur in the gall bladder. The body is cylindrical and curls tightly into a spiral so that it is very difficult to kill a specimen suitable for study, and the view is almost necessarily lateral. The most conspicuous feature, as in all aspidogastrids, is the ventral disc It covers most of the ventral surface and is divided into numerous transverse grooves or acetabula with muscular walls. My smallest, specimen, 5.5 mm. long, had about 26 acetabula including rudiments which first appear at the posterior end; the largest, 22 mm. in length, had about 80. Thus, the New Zealand material seems to differ from the Atlantic in reaching a larger size with a somewhat, smaller number of suckers. In all my material, also, the lateral papillae on the sides of each acetubular partition are conspicuous, tall, cone-like structures with sucker-like tips. They are, however, capable of almost complete retraction then appearing as a slit or groove. Although no figure of M. elegans shows these structures fully extended, Jägerskiöld (1899, p. 203) describes them as follows: — “Der Querwände zwischen den Sauggruben sind sehr oft an ihre Enden, da wo sie in die Aussenwände der Gruben übergehen, gleichsam in kleine, spitze, mehr oder minden konische Hoöcker ausgezogen. An der Spitze jedes dieser Hoöcker kann man gewohnlich eine kleine Einsenkung oder eine quergestellte, mehr oderminder schlitzenformige Grube beobachten.” From this description, I conclude the cone-like papillae occur in the Atlantic M. elegans although perhaps they are smaller than in New Zealand material. The large testis is always near the posterior end. Jägerskioöld found the ovary was far back near the testis in the smallest specimens, near midbody in older individuals, and about ¼ body length from the anterior end in the largest specimens. My specimens agree with the Atlantic in reproductive organs, extent of vitellaria, and egg size. The large eggs with thick yellowish shells are variable in size, 112 to 137 by 57 to 72μ. Jägerskiöld reports 130 to 140 by 75 to 80μ.

Fig. 1—Macraspis elegans from Callorhynchus milii. Lateral view. Fig. 2—Alcicornis longicornutus from Kathetostoma giganteum. Lateral view. Fig. 3—Lepidapedon congeri from Leptocephalus conger. Dorsal view. Fig. 4—L. congeri. Cirrus sac. Ventral view. Fig. 5—Lepidapedon australis from Coelorhynchus australis. Ventral view. Fig. 6—Cirrus sac of L. australis. Dorsal view.

There is another species of Macraspis in New Zealand but the specimens available, collected some years ago from the gall bladder of a “dog fish” by students at Victoria University College, are not adequate to furnish all the data needed. Two specimens are each about 43 mm. long with a thickness of about 2 mm. The estimated number of acetabula was about 300. This species is distinct from M. elegans in that the testis is near midbody so that almost half of the very long body is free of organs except the vitellaria and caecum. The lateral papillae are inconspicuous and usually retracted. The ovary is about 1/7 body length from the anterior end; eggs measure 122 to 132 by 81 to 96μ. Except for larger egg size, this species is very similar to Stichocotyle (Multicalyx) cristata Faust and Tang, 1936 from the gall bladder of a ray, Rhinoptera quadriloba, in the Gulf of Mexico. Stichocotyle cristata should be transferred, I believe, to the genus Macraspis Olsson, 1869, becoming Macraspis cristata (Faust and Tang, 1936) new combination. Faust and Tang placed considerable emphasis on “elevated, lug-like crests” on the disc. These crests involved several acetabula as if the latter had been everted, and occurred at irregular intervals. These crests occur on the New Zealand specimens also at very irregular intervals. I believe they are temporary, local elevations of the highly muscular disc similar to changes I have observed on living specimens of M. elegans. Intermediate stages in their elevation can be found. Order Gasterostomata Family Bucephalidae Only three species of sexually mature gasterostomes were collected. This number is relatively small, amounting to about 4.5 per cent, of the total number of Digenea collected. At Tortugas, Florida, among 189 species of Digenea there were 16 species of gasterostomes or about 8 per cent. A Prosorhynchus species in an immature state was collected from Arripis trutta Forster, the kahawai, and Helicolenus percoides Richardson, the sea perch. In so far as they can be identified without knowledge of the extent of the uterus and the egg size, they are like P. facilis (Ozaki, 1924). The vitelline follicles are in two lateral rows but meet anterior to the caecum; the mouth is near midbody or slightly posterior, the caecum is directed anteriorly; the cirrus sac does not extend beyond the posterior edge of the posterior testis. 2. Telorhynchus arripidis Crowcroft, 1947. Host: Arripis trutta Forster, kahawai; intestine. Locality: Wellington. This species was described from this same species of host in Tasmania. 3 Alcicornis longicornutus n.sp (Fig. 2) Host: Kathetostoma giganteum Haast; monk fish; intestine. Locality: Wellington. Holotype: U.S. Nat. Mus. Helminth. Collection No. 49116. Description (based on a single specimen): Length 2.044 mm.; thickness 0.539 mm. Rhynchus with rounded posterior end, 0.308 mm. long; 0.233 mm. in greatest width. Seven tentacles 0.416 to 0.478 mm. long, each with a single

prong near its base. Mouth anterior to midbody, 0.784 mm. from anterior end of body. Pharynx 0.119 mm. long by 0.112 mm. wide; caecum short, lined with tall cells. Testes ovoid, diagonal, more or less separated by cirrus sac; anterior testis just posterior to midbody. Cirrus sac long and slender, 0.624 by 0.146 mm., its anterior end overlapping ovary dorsally. Seminal vesicle bipartite, consisting of two ovoid regions; pars prostatica long Atrial sac 0.308 mm long by 0.200 mm. wide; genital pore a little in front of posterior end of body. Ovary ovoid, immediately anterior to anterior testis. Uterus extending anteriorly only to level of mouth. Eggs 21 to 25 by 13 to 15μ. Vitelline follicles 16 on each side between mouth and rhynchus. Excretory pore terminal; excretory vesicle extending dorsal to cirrus sac to posterior limit of vitellaria then bending sharply ventrad, ending just posterior to mouth. Discussion: The genus Alcicornis was named, but very incorrectly described by MacCellum (1917). For a time it was considered a synonym of Bucephalus. Nagaty (1937) discovered in A. baylisi that the anterior organ is not a sucker but a rhynchus, and the genus is now generally recognized as a bucephalid with a rhynchis bearing tentacles. Only two species have been named: A. carangis MacCallum, 1917 from Caranx ruber from Key West, Florida in the New York Aquarium, and A. baylisi Nagaty, 1937 from Caranx sp. from the Red Sea. A. longicornutus differs from A. baylisi in having a single prong on the tentacles, much longer tentacles, longer cirrus sac, position of the vitellaria, less pointed rhynchus and other characters. It is more like A. carangis but the latter is too incompletely described for very valid comparison. Both species have single pronged tentacles and a long cirrus sac. A. carangis appears to have a more pointed rhynchus, more anterior extent of the uterus, more posterior vitellaria, smaller genital atrium, more anterior genital pore, and different shape of the seminal vesicle. The tentacles had macerated in MacCallum's specimens. 4. Dolichoenterum longissimum Ozaki, 1924. Host: Leptocephalus conger (Linn.), conger eel; intestine. Locality:- Wellington. Specimen Deposited: U.S. Nat. Mus. Helminth. Collection No. 49155. Discussion: One adult and one immature specimens were collected. The large specimen measured 16.5 by 1.904 mm., thus exceeding Ozaki's upper limit for the species by more than 3 mm. This huge size is very striking when compared with the minute size of most gasterostomes. The immature specimen was 5.110 mm. long. Ozaki's specimens described and figured in Ozaki (1928) were from Leptocepialus myriaster in Japan. Yamaguti (1934) reported the species from the same host species and from Muraenesox cinereus. In 1938, Yamaguti again reports it from the conger eel (Conger myriaster). Ozaki's size records were 5.33 to 13.3 mm., Yamaguti's 4.5 to 9.3 mm. Yamaguti reported larvae in the stomach of Cepola schlegeli. My specimen agrees well with descriptions of D. longissimum except in egg size which does not seem to exceed 23 by 12 to 13μ. Ozaki reports 23 to 27 by 16 to 19μbut Yamaguti thought these measurements were from eggs at an angle and reportts 27 to 32 by 16 to 19μ(in balsam mounts). Considering that the eggs in my specimen were very thin-shelled and considerably collapsed, it does not seem advisable to base a new species on this difference.

A small immature specimen of a Dolichoenterum species was collected from the intestine of Coelorhynchns australis. It was practically a duplicate of my Dolichoenterum sp. from a deep sea fish, Citharichthys cornutus, at Tortugas, Florida. It is very likely a juvenile of D. longissimum. Order Prosostomata Family Opistholebetidae 5. Choanomyzus tasmaniae Manter and Crow-croft, 1950. Host: Notothenia macrocephala Gunther, maori chief; intestine. Locality: Wellington. Specimen Deposited: U.S. Nat. Mus. Helminth. Collection No 49156. Discussion: Three specimens were collected from one host. The sacular enlargement following the prostatic vesicle was not present; it is probably a temporary swelling. The vitelline follicles did not meet medianly posterior to the pharnyx and tended to separate into a posterior group and an anterior group on each side; however, in all the small gaps between them vitelline cells without yellow granules can be seen. This species is previously known from Dactylosargus arctidens in Tasmania. Family Lepocreadiidae 6. Lepidapedon congeri n. sp. (Figs. 3–4) Host. Leptocephalus conger (Linnaeus), conger eel; intestine. Locality: Wellington. Holotype: U.S. Nat. Mus. Helminth. Collection No. 49117. Description (based on one specimen) Length 4.410 mm.; width 1.400 mm Body tapering from near posterior end; posterior end broadly rounded, without spines which, however, had almost surely been present but lost. Oral sucker 0.292 mm.; acetabulum 0.377 mm in diameter. Sucker ratio 1:13 Forebody long, 1.750 mm. Posttesticular space short, 0.560 mm. Prepharynx 0.455 mm. long; pharnyx 0.215 mm. long by 0.192 mm. wide; oesophagus 0.192 mm. long; bifurcation 0.577 mm. anterior to acetabulum; caeca ending near posterior end of body. Testes tandem, close together, in posterior half of hindbody; anterior testis slightly lobed, posterior testis smooth Common genital pore median or sub-median, a short distance anterior to acetabulum Cirrus sac (Fig. 4) with anterior and posterior swollen regions separated by a narrow isthmus lying to the right opposite middle half of acetabulum. Posterior end of cirrus sac slightly posterior to acetabulum, much less than halfway to ovary. Seminal vesicle internal, tubular, making one loop in the posterior portion of the cirrus sac and becoming sinuous in the anterior portion Gland cells in both portions of cirrus sac but not in the connecting isthmus. Ovary trilobed, to right of midline, slightly anterior to anterior testis. Seminal receptacle elaviform, extended transversely, lying at posterio-right of ovary, overlapping anterior testis. Uterus to left of and anterior to ovary, its terminal portion (anterior to acetabulum) a thin-walled straight tube surrounded by some gland cells. Vitellaria from level of intestinal bifurcation to posterior end of caeca, chiefly lateral and ventral to caeca but

extending to midline between acetabulum and bifurcation and filling most of the posttesticular space. Eggs thin-shelled, 50 to 60 by 27 to 34μ measured in balsam mount. Excretory pore subterminal, dorsal; excretory vesicle extending anterior to the acetabulum to the intestinal bifurcation. Discussion: This species keys to L. hancocki Manter, 1940 in Hanson's (1950) key to species of Lepidapedon. It differs markedly, however, in its small size; extent and structure of the cirrus sac; in its long prepharnyx; sucker ratio; and extent of Vitellaria. L. congeri is perhaps more closely related to L. rachion which, however, has an oral sucker larger than the acetabulum and an excretory vesicle not reaching anterior to the testes. The ovary of L. congeri is more lobed than that of a any other species, and in only a few species does the excretory vesicle extend anterior to the acetabulum. L. nicolli Manter, 1934 has the long excretory vesicle but, differs in having the oral sucker larger than the acetabulum, very short prepharnyx, unlobed ovary, and differently shaped cirrus sac. The long prepharnyx and the rather scanty prostatic cells of L. congeri suggest the genus Pseudolepidapedon Yamaguti, 1938, but the latter genus lacks a seminal receptacle. 7. Lepidapedon australis n. sp. (Figs. 5–6) Host: Coelorhynchus australis (Richardson), rat fish; intestine. Locality: Wellington. Holotype U.S. Nat. Mus. Helminth. Collection No. 49118. Description (based on 36 specimens; measurements on 13 specimens): Body flattened, elongate, spined. Spines more dense anteriorly, becoming sparse at posterior end, lost posteriorly as body macerates. Length 4.088 to 6.636 mm.; greatest width near posterior end, 0.504 to 1.036 mm. Body tapering gradually toward anterior end and broadly rounded at posterior end. Oral sucker 0.154 to 0.231 mm. wide; acetabulum 0.177 to 0.269 mm. wide. Sucker ratio 1:1.03 to 1.30, usually 1.12 to 1.18. Forebody 1.470 to 2.688 mm., usually a little less than ½ body length (½.1 to ⅓.4). Prepharynx 0.192 to 0.470 mm.; pharynx 0.107 to 0.146 mm. long by 0.070 to 0.092 mm wide; oesophagus 0.139 to 0.423 mm. long; usually somewhat larger than prepharynx, in only three specimens was it somewhat shorter. Intestinal epithelium begins slightly anterior to bifurcation. Intestinal bifurcation rarely about halfway between acetabulum and oral sucker, usually somewhat nearer to oral sucker than to acetabulum; distance from acetabulum 0.801 to 1.540 mm. Caeca only slightly divergent, narrow, reaching to near posterior end of body. Testes rounded, smooth, sometimes slightly wider than long, tandem, close together, in posterior half of hindbody. Posttesticular space 0.756 to 1.288 mm. long. Cirrus sac (Fig. 6) divided by a narrow portion into two parts Posterior part postacetabular. subglobular, filling most of intercaecal area immediately posterior to acetabulum, containing a sinuous, tubular seminal vesicle and numerous gland cells. Narrowed portion of cirrus sac with a bend or curve, mostly dorsal to acetabulum. Anterior portion rounded anteriorly, club-shaped, extending anterior to genital pore, containing small cells and a muscular cirrus Genital pore slightly anterior and slightly to left of acetabulum. Ovary

rounded, immediately pretesticular, near middle of hindbody. Seminal receptacle rounded, at left posterior border of ovary. Mehlis' gland preovarian. Vitelline follicles not extending anterior to posterior end of cirrus sac, usually not reaching cirrus sac by short distance; lateral, dorsal, and ventral to caeca. In a single specimen, the vitellaria did not reach the seminal vesicle by a distance of 0.693 mm., but in all others this distance was 0 to 0.131 mm. Eggs thin-shelled, 80 to 92 by 55 to 65μ. Metraterm to left of cirrus sac, surrounded by small gland cells dorsal to acetabulum. Excretory vesicle extending only to posterior testis; collecting tubules ending shortly anterior to pharynx. The name australis is for the geographical location of this species in the Southern Hemisphere. Discussion: In Hanson's (1950) key to species of Lepidapedon this species keys to L. elongatum. However, it differs from descriptions of L. elongatum in less anterior extent of the vitellaria especially in relation to the cirrus sac; in anterior extent of the excretory vesicle which extends to the anterior testis in L. elongatum; in the shape of the cirrus sac; in the proximity of the testes to one another; and in having much larger eggs. The “L. elongatum” reported by Manter (1934) from deepwater fishes at Tortugas, Florida, is probably not L. elongatum although it does agree well with the “L. elongatum” he reported from the coast of Maine. Both of these forms have the intestinal bifurcation much too near the acetabulum to be L. elongatum. L. australis is most similar to L. coelorhynchi Yamaguti, 1938 from Coelorhynchus sp. in Japan. It differs (1) in the shape of the cirrus sac which is more rounded posterior to the acetabulum and more extensive and wider anterior to the acetabulum; (2) the testes are close together and not separated by vitellaria; (3) the excretory vesicle extends only to the posterior rather than to the anterior testis; (4) the eggs are much larger. Hanson (1950) was inclined to consider L. coelorhynchi a synonym of L. elongatum. The only differences seem to be the anterior extent of the vitellaria and possibly the shape of the cirrus sac. 8. Neolepidapedon polyprioni n.gen., n.sp. (Figs. 7–8) Host: Polyprion oxygeneios (Bloch & Schn.), groper; intestine. Locality: Portobello. Holotype: U.S. Nat. Mus. Helminth. Collection No. 49119. Description (based on 13 specimens with measurements on 5): Body flattened, elongate; 5.082 to 5.740 mm. by 0.868 to 0.980 mm. wide; almost equally wide along most of its length, rounded at each end; armed with scale-like spines which disappear at about level of ovary or become very sparse posterior to that level. Oral sucker 0.231 to 0.277 mm. wide; acetabulum 0.231 to 0.285 mm. wide; sucker ratio almost exactly 1:1. Forebody 0.990 to 1.400 or approximately ¼ to ⅕ body length. Prepharynx shorter than oesophagus, 0.070 to 0.115 mm. long; pharynx 0.192 to 0.269 by 0.085 to 0.100 mm.; oesophagus 0.192 to 0.269 mm. long; intestinal bifurcation approximately midway between suckers; distance from bifurcation to acetabulum 0.369 to 0.554 mm.

Testes tandem, just posterior to middle of hindbody, usually slightly lobed but sometimes smooth (in 4 of 13 specimens), somewhat separated except in contracted specimens; posttesticular space 1.302 to 1.568 mm., equal to or somewhat longer than forebody. Seminal vesicle tubular, beginning posterior to acetabulum a distance aproximately the diameter of the latter, more or less sinuous particularly along posterior edge of acetabulum near its entrance to cirrus sac; surrounded by large gland cells which are not enclosed in a membrane. Cirrus sac (Fig. 8) ovoid, thick-walled, dorsal to acetabulum, approximately same length as acetabulum. Posterior half mostly filled by the thick wall of a narrow, straight sperm duct; this wall contains fine circular fibers and probably functions as a sphincter. Anterior half of cirrus sac containing an ovoid prostatic vesicle with large cells; only a few gland cells; and a short, almost spherical cirrus. Genital pore slightly to the left and slightly anterior to acetabulum. A curved, transverse fold of the cuticula lies immediately anterior to the acetabulum and becomes well elevated in contracted specimens. The genital pore lies just beyond or at the base of this cuticular fold. Ovary approximately in middle of hindbody, separated from anterior testis by a short space which, in contracted specimens, may be filled by the spherical seminal receptacle which is partly dorsal and partly posterior to ovary. Ovary usually with slightly irregular contour, tending to be subtriangular or very broadly three-lobed, but rarely ovoidal. Vitelline follicles may begin at posterior edge of the gland cells of the seminal vesicle but usually 0.1 to 0.5 mm. posterior to that level, extending unbroken to near posterior end of body, intruding but usually not quite meeting between testes; ventral, lateral and dorsal to caeca. Eggs thin-shelled, 90 to 96 by 37 to 50μ. (in mounted specimens). Metraterm with a glandular portion dorsal to acetabulum, and a short, bipartite, thick-walled, muscular portion near genital pore. Excretory vesicle extending, dorsal to testes, to near the ovary. The seminal receptacle often indents the anterior end of this vesicle. Discussion: The genus Neolepidapedon is proposed to accommodate those species like Lepidapedon species except that no membrane surrounds the gland cells of the posterior portion of the seminal vesicle. There is some confusion in descriptions of Lepidapedon regarding this glandular portion often referred to as an “external seminal vesicle.” It is separated by a deep constriction or by a narrow isthmus from a more anterior, typical cirrus sac containing a seminal vesicle, prostatic cells, and cirrus. Its membrane is apparently continuous with the wall of the cirrus sac, and it is probably more correct to describe the cirrus sac as divided into two distinct portions. Most species named in Lepidapedon show this characteristic. It was not mentioned nor figured for L. hancocki Manter, 1940 but a restudy of specimens reveals that a very thin membrane does surround the conspicuous gland cells present in that species. L. sebastisci Yamaguti, 1938 and L. hoplognathi Yamaguti, 1938 both lack such a membrane and are transferred to Neolepidapedon. Genetic Diagnosis OF Neolepidapedon: Lepocreadiidae. Prepharynx and oesophagus present. Gonads tandem. Cirrus sac present. External seminal vesicle tubular, surrounded by gland cells lying free in the parenchyma. Uterus preovarian. Seminal receptacle near posterior border of ovary. Like Lepidapedon except gland cells of posterior portion of seminal vesicle not enclosed

Fig. 7—Neolepidapedon polyprioni from Polyprion oxygeneros. Ventral view. Fig. 8—Terminal genital organs of N. polyprioni. Ventral view. Fig. 9—Neolepidapedon cablei from Lotella rhacinus. Ventral view. Fig. 10—Terminal genital organs of N. cablei. Dorsal view. Fig. 11 — Proenenterum isocotylum from Notothema macrocephala. Ventral view. Fig. 12—Cirrus sac of P. isocotylum. Ventral view. Fig. 13—Egg of P. isocotylum. Fig. 14—Proenenterum ericotylum from Notothenia macrocephala.

in a membrane. Type species: N. polyprioni. Other species: N. sebastisci (Yamaguti, 1938) n. comb. (synonym: Lepidapedon sebastisci Yamaguti, 1938); N. hoplognathi (Yamaguti, 1938) n. comb. (synonym: Lepidapedon hoplognathi Yamaguti, 1930). Comparisons: Compared with N. polyprioni, N. hoplognathi has a similar extent of the excretory vesicle but, among other differences, has almost no oesophagus. N. sebastisci is without doubt the most closely related species since it possesses the peculiar “thick coat of circular muscle fibers” around the internal seminal vesicle. Furthermore, the sucker ratio and extent of the vitellaria are as in my species. However, in L. sebastisci the gland cells of the seminal vesicle are not conspicuous; the two testes are more widely separated by vitellaria; the excretory vesicle reaches only to the anterior testis; a distinct metraterm is lacking; while both body and egg sizes are smaller. 9. Neolepidapedon cablei n.sp. (Figs. 9–10) Host: Lotella rhacinus (Forster), southern hake; caeca and intestine. Locality: Wellington. Holotype: U.S. Nat. Mus. Helminth Collection No 49120. Description (based on about 60 specimens, with measurements on eight. Several hundred were collected many of which were slightly macerated; others were in good condition): Body elongated and fairly thick, with spine-like scales which gradually disappear near posterior end; forebody tapering slightly; hind-body broadly rounded. Length 1.764 to 2.912 mm.; width 0.131 to 0.485 mm.; widest near acetabulum or near ovary, almost equally wide along most of its length. Forebody 0.616 to 0.882 mm. or about ⅓ body length. Oral sucker 0.106 to 0.141 mm. wide; acetabulum 0.102 to 0.152 mm. wide; sucker ratio 1:1.06 to 1.14. A small, glandular, hump-like protuberance at anterior edge of acetabulum. Prepharynx a little shorter than pharynx; pharynx 0.057 to 0.076 mm. long; 0.057 to 0.076 mm. wide; oesophagus 1 ½ to 3 times length of pharynx; bifurcation about halfway between suckers, sometimes slightly more or less: caeca ending blindly near posterior end of body. Genital pore slightly to left, immediately anterior to acetabulum, inconspicuous, usually obscured by the preacetabular hump. Testes spherical or ovoid; tandem, usually close together, rarely separated by a few vitelline follicles. Posttesticular space 0.231 to 0.588 mm. or ⅕ to 1/7 body length. Cirrus sac ovoid, 0.133 to 0.190 by 0.074 to 0.099 mm., dorsal to left half of acetabulum, containing a tubular seminal vesicle surrounded by a very thick wall with at least some circular muscles, and a few small gland cells (Fig. 10). Near the anterior end of the cirrus sac the seminal tube is surrounded by a peculiar, delicate, thin, circular structure which, unlike the non-staining muscular wall, stains lightly with Delafield's haematoxylin. The cirrus is very short but thick-walled. appearing somewhat constricted from the cirrus sac. External seminal vesicle from ¼ to ⅓ distance to ovary (from acetabulum); its anterior half a small coiled tube surrounded by very large prostatic cells free in the parenchyma; its posterior half a wider coiled tube without gland cells. Ovary spherical or ovoid, near middle of hindbody, usually directly anterior to anterior testis, rarely separated by a few vitellaria Seminal receptacle dorsal,

at posterior edge of ovary, usually partly dorsal to anterior testis. Eggs in proximal half of uterus colourless and usually uncollapsed, 57 to 68 by 38 to 47μ; eggs in distal half of uterus yellow and usually collapsed, 68 to 91 by 30 to 34μ. thus being longer and less wide than young eggs. Metraterm well developed, to right of cirrus sac, about same length as cirrus sac. Vitelline follicles rather large, showing unusual variation in extent; in most cases not reaching acetabulum by a short distance, ending near middle of external seminal vesicle; sometimes reaching a little anterior to acétabulum, especially on the right side; usually continuous to near posterior end of body, rarely interrupted opposite testes or ovary; ventral and lateral to caeca but not dorsal except near posterior end; contiguous posterior to testes. Anterior extent of excretory vesicle not determined. This species is named in honour of Dr. Raymond Cable of Purdue University. Discussion: This species differs from N. polyprioni in much smaller size: more anterior extent of vitellaria; unlobed testes; distribution of prostatic gland cells; length of metraterm; egg size; and other characters, although the two species are alike in some respects including the preacetabular hump. N. cablei differs from N. hoplognathi (Yamaguti, 1938) notably in its long oesophagus and short prepharynx; from N. sebastisci (Yamaguti, 1938) in anterior extent of the vitellaria, shape of the pharynx, and proximity of the testes. 10. Proenenterum isocotylum n.gen., n.sp. (Figs. 11–13) Host: Notothenia macrocephala Gunther, maori chief; intestine. Locality: Wellington. Holotype: U.S. Nat. Mus. Helminth. Collection No. 49121. Description (based on 6 specimens): Body elongate, somewhat flattened but robust, spined anteriorly as far back as level of ovary but spines had been lost on most specimens. Length 2.310 to 4.046 mm.; greatest width 0.588 to 0.990 mm. usually near the level of posterior testis but body almost equally wide between acetabulum and near posterior end. Posterior end usually broadly rounded but in some specimens it tapers approximately as much as the forebody. Oral sucker 0.207 to 0.285 mm. in diameter; acetabulum 0.200 to 0.300 mm. in diameter. Sucker ratio approximately 1:1 in five specimens, 1:1.22 in the other. Fore-body 0.518 to 0.868 mm. or about ¼ body length. Posttesticular space 0.532 to 0.924 mm., slightly more or less than the forebody. Prepharynx rather wide, 0.039 to 0.115 mm. long; pharynx wider than long, 0.107 to 0.192 mm. long by 0.123 to 0.231 mm. wide; oesophagus very short; bifurcation about midway between suckers; caeca rather wide particularly posterior to testes, uniting near posterior end of body; anus lacking Excretory pore terminal; excretory vesicle I-shaped, extending ventral to caceal union then dorsal to testes to near ovary. Testes large, tandem, close together, intercaecal. lobed: anterior testis just posterior to midbody. Cirrus sac (Fig. 12) large, ovoid, only slightly longer than wide, filling space between acetabulum and intestinal bifurcation, overlapping slightly both the acetabulum and the bifurcation; length 0.154 to 0.323 mm.; width 0.138 to 0.300 mm.; containing a tubular, much coiled seminal vesicle, a few prostatic cells, and a short cirrus; external seminal vesicle lacking. Genital pore slightly to the left, a little posterior to the intestinal bifurcation.

Ovary 3-lobed, immediately pretesticular, median. Seminal receptacle dorsal to ovary. Vitellaria from level of intestinal bifurcation to posterior end of body; lateral, dorsal and ventral to caeca; filling posttesticular space Uterus irregularly coiled between posterior edge of ovary and acetabulum, with relatively thick, or at least deeply staining wall; metraterm lacking; uterus joins cirrus near genital pore. Eggs thin-shelled, 54 to 65 by 34 to 38μ, usually about 60 by 38μ, with a short point at the anopercular end (Fig. 13). Discussion: In most respects this trematode is a fairly typical Lepocreadid. The union of the intestinal caeca is unusual in the family. The digestive system, the robust body, the large testes and cirrus sac suggest the genus Enenterum Linton, 1910. However, Enenterum has an anus, processes on the oral sucker and an external seminal vesicle. Proenenterum is more typical of the family and more or less connects the unusual Enenterum and related genera with other genera in the Lepocreadiidae. Nagaty (1948) has discussed genera related to Enenterum including Spiritestis Nagaty, 1948; Hairana Nagaty, 1948; Cadentella Nagaty, 1948; and Jeancadenatia Nagaty, 1948. The latter two genera were elevated from subgenera of Dollfus (1946). These genera show a number of characters uncommon among trematodes, namely: lobing of the oral sucker, accessory ventral suckers, caecal union, anus, and single testis Only Hairana resembles Proenenterum in absence of oral lobes, but it differs markedly in that its caeca do not unite, it has a single testis and a metraterm pouch. All genera in the group have a well developed cirrus sac but an external seminal vesicle may or may not be present, and a seminal receptacle is reported as absent, in Hairana. Generic Diagnosis OF Proenenterum: Elongate Lepocreadiidae Body spines easily lost. Oral sucker without lobes. Acetabulum about ¼ from anterior end. Prepharynx present; caeca unite posteriorly; anus lacking. Gonads tandem, close together. Two testes. Cirrus sac largely preacetabular; external seminal vesicle lacking. Uterus preovarian; seminal receptacle present; metraterm sac lacking; eggs thin-shelled with point at posterior end. Excretory vesicle I-shaped. Parasites in marine fishes. Type species: P. isocotylum. The name Proenenterum indicates relationship to the genus Enenterum. The name isocotylum is from iso, equal, and cotyl, cup-shaped, and refers to the subequal size of the suckers. 11. Proenenterum ericotylum n.sp. (Fig. 14) Host: Notothenia macrocephala Gunther, maori chief; intestine. Locality: Wellington. Holotype: U.S. Nat. Mus. Helminth. Collection No. 49121. Description (based on 14 specimens with measurements on 6): Body elongate: no spines present but evidence that they had been lost; probably normally spined anterioily. Length 3.556 to 4.844 mm.; greatest width 0.798 to 1.162 mm. at near acetabular level but body almost equally as wide until posterior to testes. A 2.758 n. m. specimen was immature. Forebody 1.022 to 1.218 mm. or approximately ¼ body length. Post-testicular space 0.728 to 1.288 mm. or a little more or less than forebody length. Oral sucker 0.277 to 0.400 mm. wide; acetabulum 0.515 to 0.708 mm. wide; sucker ratio 1:1.71 to 1.86. Prepharynx at least

slightly shorter than pharynx; pharynx 0.138 to 0.323 mm. long by 0.146 to 0.262 mm. wide; oesophagus very short or lacking; intestinal bifurcation approximately midway between suckers; caeca uniting near posterior end of body; anus lacking. Testes large, tandem, close together, smooth or slightly lobed; anterior testis just posterior to midbody. Cirrus sac ovoid, slightly wider than long, filling space between intestinal bifurcation and acetabulum, containing a much coiled, tubular, seminal vesicle, a muscular cirrus, and a few prostatic cells. External seminal vesicle lacking. Genital pore slightly to the left of midline just posterior to intestinal bifurcation. Ovary spheroid, unlobed, median or submedian, immediately pretesticular. Seminal receptacle at right posterior edge of ovary. Laurer's canal present, opening dorsal to ovary. Mehlis' gland consists of very extensive gland cells anterior to ovary. Vitellaria from posterior edge of acetabulum to posterior end of body, sometimes as far forward as midacetabular level. Uterus with few coils between anterior testis and acetabulum, one coil reaching posterior edge of ovary; metraterm lacking. Eggs with short pointed knob at anopercular end, thin-shelled, 42 to 53 by 30 to 38μ. Excretory pore subterminal; excretory vesicle I-shaped, extending ventral to the caecal union, then dorsal to the testes to near the ovary. The name ericotylum is from eri. a strengthening, and cotylum, cup, and refers to the larger suckers particularly the acetabulum as compared with P. isocotylum. Discussion: These trematodes were in the same collection and from the same host as P. isocotylum. The presence of two species became obvious when specimens were studied. P. ericotylum has a much larger acetabulum; also, the ovary is unlobed: the vitellaria do not extend anterior to the acetabulum; the testes are unlobed or only slightly lobed: the body size somewhat larger; the uterus shorter and the eggs somewhat smaller. These differences are rather typical specific differences among trematodes. Although the species were living together in the same host there were no intergradations between them except in body size, egg size, and contour of the testes. 12. Holorchis pulcher n. sp. (Fig. 15) Host: Latridopsis ciliaris (Forster), moki; intestine. Locality: Wellington. Holotype: U.S. Nat. Mus. Helminth. Collection No. 49123. Description (based on 5 mature specimens): Length 3.220 to 3.920 mm.; greatest width, near acetabulum, 0 868 to 1.050. A 2.968 mm specimen was immature. Cuticula spined over entire body but spines become sparse posterior to level of testes. Forebody 0 658 to 1.008 mm. or about 1.3.8 to 4.8 compared with body length Post-testicular space 1 120 to 1 344 or 1:2.5 to 3 compared with body length. Oral sucker slightly longer than wide; width 0 192 to 0.231 mm.; acetabulum circular, 0 192 to 0.223 mm., equal to or very slightly smaller than oral sucker. Pharynx slightly longer than wide, 0 123 to 0.138 mm. long by 0 093 to 0.123 mm. wide. Oesophagus shorter than pharynx, bifurcation about

midway between suckers; caeca narrow, extending almost to posterior end of body. Testes tandem, close together, intercaecal, at about midbody level; deeply lobed. Cirrus sac club-shaped, its opening median at level of pharynx, extending to anterior edge of acetabulum; length 0.385 to 0.525 mm, width 0 115 to 0.138 mm. Internal seminal vesicle small, ovoid, followed by a prostatic vesicle of about the same size; cirrus long, coiled when retracted, often protruded as a muscular tube. External seminal a swollen tube which bends once dorsal to acetabulum thus being more or less S-shaped and extends slightly posterior to acetabulum. Ovary deeply lobed and irregular in shape with 4 to 6 lobes; to right of midline just posterior to acetabulum. Seminal receptacle a large elongate sac originating at left anterior edge of ovary and extending posterior to ovary. Vitelline follicles fairly small, from level of anterior edge of acetabulum to end of caeca. Anterior to the testes they are lateral to the caeca but posterior to the testes they become more dense and are confluent in the posttesticular space although there they are not so close together. Uterus extending backward in short coils to the anterior testis then forward to near anterior edge of acetabulum where it joins the conspicuous metraterm. Metraterm club-shaped approximately the same size as cirrus sac, opening slightly to the anterior left of the male pore. Metraterm content staining deeply with Delafield's stain. Thin-shelled, uncollapsed eggs 49 to 60 by 32 to 42μ, usually 53 to 57 by 38μ; collapsed eggs 53 to 57 by 27 to 36μ. Excretory pore terminal; excretory vesicle extending to posterior testis. Discussion: The genus Holorchis was named by Stossich (1900) with H. pycnoporus as type species, a trematode in Sargus salviani at Trieste. The only other species named in the genus is H. legendrei Dollfus, 1946 from Mullus surmuletus from the North-Western coast of Prance. That species Dollfus assigned to the genus provisionally because Stossich's description of the genus is incomplete notably in respect to the cirrus sac, seminal vesicle and seminal receptacle. Stossich's figure and description indicate a Lepocreadid with at least a part of the seminal vesicle outside any cirrus sac but unlike Lepocreadium in that the uterus extends posterior to the ovary between it and the anterior testis. Assuming a cirrus sac and a seminal receptacle to be present, that trematode appears congeneric with H. legendrei and H. pulcher. As Dollfus (1946) points out the type material of H. pycnoporus needs to be studied to confirm the genus. It seem probable that Holorchis is a genus of Lepocreadiidae similar to Lepocreadium except for the posterior development of the uterus which separates the ovary and anterior testis by some distance. It is very probable that when H. pycnoporus is better known the genus Aephnidiogenes Nicoll, 1915 will fall as a synonym. Although the genus was originally described as lacking a cirrus sac, Yamaguti (1934) states that a cirrus sac with internal seminal vesicle is present. Three species of Aephnidiogenes have been named (A. barbatus Nicoll, 1915; A. major Yamaguti, 1934; A. isagi Yamaguti, 1939) all from Pacific fishes. These species all differ from the above three species of Holorchis in that the testes are separated by a distance equal to their length but this is surely not a generic difference. H. pulcher differs from both old world species in its lobed ovary and testes, its more anterior genital pore, relatively smaller acetabulum, and more anterior extent of the vitellaria, It differs from the species named in Aephnidiogenes in

Fig. 15—Holorchis pulchrius from Latridopsis ciliaris. Ventral view. Fig. 16— Myzoxenus croworofti from Pseudolabrus pittensis. Ventral view. Fig. 17—Acetabulum of M. crowcrofti. Lateral view. Fig. 18—Terminal genital organs of M. crowcrofti Fig. 19—Pancreadium otagoensis from Parapercis colias. Dorsal view. Fig. 20—Terminal portion of male reproductive system of P. otagoensis. Dorsal view. Fig. 21—Stephanostomum australis from Cheilonichthys kumu. Ventral view. Fig. 22—Anterior end of S. australis. Ventral view. Fig. 23—Eggs of S. australis.

much more anterior genital pore, better development of the cirrus sac and metra term, and in having contiguous testes. The name pulcher, beautiful, was suggested by the general appearance of the trematode. 13. Myzoxenus crowcrofti n.sp. (Figs. 16–18) Host: Pseudolabrus pittensis Waite. kelp fish; intestine. Locality: Brothers Island. Holotype: U.S. Nat. Mus. Helminth. Collection No. 49124. Description (based on 18 specimens, with measurements on six): Body normally spined but with spines easily lost; length 1.948 to 2.996 mm., width 0.616 to 1.050 mm., greatest width at or near posterior end. Forebody 0.616 to 0.910 mm. or about ⅓ to ¼ body length, not much tapered. Posttesticular space 0.616 to 1.078 mm., nearly, or somewhat longer than, the length of the forebody. The body is narrowest at acetabular level; the hindbody gradually widens to the posterior end which is abruptly truncate. Oral sucker 0.177 to 0.300 mm. wide, more or less truncate at its posterior edge. Acetabulum protuberant; deep; 0.323 to 0.485 mm. long; width rarely observed due to projection of the sucker. Sucker ratio (in this case width of oral sucker to length of the acetabulum): 1:1.7 to 2.2. Acetabulum with a pair of lateral folds longitudinally striated (Fig. 17). Prepharynx thick-walled, 0.061 to 0.115 mm. long; pharynx 0.115 to 0.169 mm. long by 0.131 to 0.192 mm. wide; oesophagus 0.092 to 0.154 mm. long, sometimes as long as pharynx but usually somewhat shorter; bifurcation not far anterior to acetabulum, nearer acetabulum than to oral sucker; caeca almost straight posterior to acetabulum becoming wider posterior to testes, ending blindly near posterior end of body. Genital pore to the left at level of pharynx, usually well to the left, but sometimes apparently only slightly so. The somewhat cylindrical forebody was bent at such angles as to explain some of this variation. Testes in anterior half of hindbody, extended transversely, filling intercaecal space, tandem, close together. Seminal vesicle (Fig. 18) starts as a spherical sac near posterior edge of acetabulum; a narrow tube from this portion becomes enlarged to a spindle shape, then narrows but soon enlarges again to form a second spindle shaped swelling from which a narrow tube leads to the cirrus sac. Cirrus sac elongate, tapering toward its posterior end, containing a tubular (not sac-like) internal seminal vesicle, a few gland cells, and a short cirrus. The length of the cirrus sac is usually only slightly longer than the pharynx ventral to which it lies. In most specimens it measured 0.118 to 0.160 by 0.046 to 0.068 mm., but in one case it was much larger, 0.266 by 0.053 mm. A short genital atrium is present. The three regions of the external seminal vesicle are constant and consist of a spherical sac and two spindle shaped swellings separated by a narrow tube. Ovary ovoid or subspherical, slightly wider than long, to the right, immediately in front of testes. Seminal receptacle large, dorsal and to left of ovary. Uterus short with few coils, preovarian, becoming straight dorsal to acetabulum; metraterm shorter than cirrus sac. Eggs 57 to 74 by 28 to 42μ, usually 65 to 68 by 30 to 34μ; when uncollapsed 65 to 74 by 38 to 42μ. Vitellaria of distinct, typical follicles, from level of ovary to extreme posterior end of body; filling most of body posterior to testes; extending around posterior tips of caeca Most

anterior extent of vitellaria observed was the posterior border of acetabulum. Forebody containing vitellaria-like cells without vitelline granules. Excretory pore on a papilla lying in a pit at posterior end of body; excretory vesicle extending to posterior testis. The species is named for Peter Crowcroft, a pioneer in the study of trematodes of marine fishes of Tasmania. Discussion: Three species of Myzoxenus have been named: M. vitellosus Manter, 1934; M. lachnolaimi Manter, 1947; and M. insolens (Crowcroft, 1945) M. crowcrofti is most similar to M. solens from a related host, Pseudolabrus tetricus, in Tasmania. A number of small differences occur. The forebody of M. crowcrofti is less tapering, the acetabulum more protuberant, the posterior end truncate rather than broadly rounded; the posttesticular space is much longer; eggs are definitely larger; the vitellaria do not extend quite so far forward and are not crowded together; and the cirrus sac is smaller and more slender. The genus Myzoxenus is surely related to the genus Labrifer Yamaguti, 1936. In Labrifer the striated lobes of the acetabulum are anterior and posterior, and both of its species, L. semicossyphi Yamaguti, 1936 and L. secundus Manter, 1940, are described as unspined. Both genera probably belong in the family Lepocreadiidae. The host and geographical distribution of these odd, distinctive trematodes are of interest. Two species of Myzoxenus occur at Tortugas, Florida, two in the South Pacific (Tasmania and New Zealand). One species of Labrifer occurs in Japan, the other off the Pacific coast of Mexico. All six species agree in having members of the family Labridae as hosts, although one, M. vitellosus, can also occur in Calamus (family Sparidae). I have already noted (Manter, 1947) that Tortugas, Florida has stronger Pacific than Atlantic connections by way of the former continuity of the two oceans and their present and long standing continuity through the deep sea. 14. Pancreadium otagoensis n.gen., n.sp. (Figs. 19–20) Host: Parapercis colias (Forster), blue cod; intestine. Localities: From aquarium, Portobello Marine Laboratory: six specimens in stomach; three in gall bladder; hundreds in intestine. Wellington: one specimen. Holotype: U.S. Nat. Mus. Helminth. Collection No. 49125. Description (based on about 50 specimens with measurements on seven). Length 1.890 to 2.716 mm., greatest width 0.980 to 1.162 mm., near midbody; tapering toward each end but more broadly rounded posteriorly. Body spined; spines becoming more widely spaced in posterior half. Cuticula of average thickness except in posterior third where it is somewhat thicker. Oral sucker 0.192 to 0.223 mm. in transverse diameter; acetabulum subcircular. 0.285 to 0.323 mm. in diameter. Sucker ratio 1:1.3 to 1.5. Forebody 0.518 to 0.798 mm., subject to contraction but usually approximately ⅓ body length. Posttesticular space 0.392 to 0.798 mm., about ¼ to ⅙ total body length. Prepharynx present, when extended almost as long as pharynx; pharynx 0.123 to 0.146 mm. long by 0.092 to 0.115 mm. wide; oesophagus when extended about same length as

pharynx; bifurcation midway between suckers; caeca bowing outward, ending just past the posterior testis a short distance in front of posterior end of body. Genital pore median, immediately posterior to or sometimes opposite intestinal bifurcation. Testes large, elongate oval, usually smooth, sometimes slightly lobed; diagonal; separated by excretory vesicle; anterior testis partly to the right of ovary, not far posterior to the acetabulum from which it is usually separated by the uterus. It may overlap the acetabulum. Cirrus and cirrus sac lacking. Seminal vesicle a coiled tube partly dorsal and partly to right of acetabulum, not extending posterior to acetabulum but often reaching to the ovary at posterior border of acetabulum; coils varying but tending to be longitudinal (Fig. 20). Ovoid prostatic vesicle present from which a short thin-walled tube leads to the genital pore. Prostatic cells not closely associated with male tube but small gland cells dorsal to region of intestinal bifurcation may be prostatic. Ovary near the posterior right edge of acetabulum, 4-lobed with three very distinct radial lobes and a fourth dorsal lobe. Seminal receptacle club-shaped, extending posterior to ovary Vitelline follicles fairly large, from level of oesophagus to near posterior end of body, converging medianly anterior to acetabulum where they may meet; mostly lateral to the caeca; almost or sometimes actually meeting posterior to testes. Yolk reservoir just posterior to ovary. Uterus extending to left of ovary to the left caecum then forward to the genital pore; metraterm lacking. Eggs frequently abnormal, perhaps because of the intensity of the infection; those fully formed 65 to 72 by 30 to 38μ. Excretory pore terminal; excretory vesicle bending between testes to end with irregular border at the transverse yolk duct at level of posterior edge of ovary. Posterior portion of vesicle glandular. Discussion: It was at first believed this species could be placed in either the genus Homalometron Stafford, 1904 or the closely related genus Crassicutis Manter, 1936. But some of its most conspicuous features such as its deeply lobed, clove-leaf shaped ovary; the large, diagonal testes; and the excretory vesicle winding between the testes seem to relate it more to the genus Lepocreadioides Yamaguti, 1936. Lepocreadioides, however, has a cirrus sac and a genital pore far to the left and far anterior. L. zebrini Yamaguti, 1936 and L. branchiostegi Yamaguti, 1937 both have excretory vesicles extending anterior to the acetabulum, but in L. indicum Srivastava, 1941 the vesicle extends only to the ovary. Generic Diagnosis OF Pancreadium: Lepocreadiidae. Body more of less ovate and flattened; spined. Acetabulum a little larger than oral sucker. Prepharynx, pharynx, and oesophagus present; caeca end blindly. Testes large, diagonal, intercaecal, separated by excretory vesicle. Genital pore median, near intestinal bifurcation. Cirrus and cirrus sac absent; seminal vesicle tubular, more or less coiled; prostatic vesicle present. Ovary deeply 4-lobed, to the right, immediately postacetabular; seminal receptacle posterior to ovary; vitelline follicles from oesophagus to near posterior end; uterus not extending posterior to ovary. Excretory vesicle extending between testes to level of ovary. Type species: Pancreadium otagoensis. The name Pancreadium, is from pan, all, and creadium from the genus Creadium and refers to the combining of characters of several genera in the family. The name otagoensis is for the locality.

This genus differs from Homalometron and Crassicutis in its lobed ovary and excretory vesicle winding between the testes. It differs from Homalometron also in its diagonal testes and more extensive vitellaria. It is like Lepocreadioides except that it lacks a cirrus sac and has a median, more posterior genital pore. 15. Pseudocreadium monacanthi Layman, 1930 Synonym: Leptocreadium skrjabini Ozaki, 1936 Host: Cantherines scaber (Bloch & Schm.); leather jacket; intestine. Locality: Wellington. Specimen Deposited: U.S. Nat. Mus. Helminth. Collection No. 49157. Discussion: Three specimens, one barely mature, were collected. They agree with P. monacanthi in almost all details. They are smaller (0.778 to 0.969 mm. compared with 1.47 to 2.45 mm.) but are probably younger. Eggs were 60 to 76 by 30 to 57μ, compared with 50 to 67 by 30 to 40μ, but only uncollapsed eggs were more than 38μ wide. The only difference I can detect, other than size, is that the ovary appears to be segmented into two or three masses each of which tends to be irregularly lobed. However, P. monacanthi has a “grape-like ovary” or one “divided into lobules.” Figures by both Layman (1930) and Ozaki (1936) show these lobules connected or at least in contact. Such a condition might develop with age. It is of interest to note that P. monacanthi is previously known from Monacanthus cirrhifer, Cantherines modestus, and C. unicornu from the North Pacific. 16. Stegodexamene anguillae Macfarlane, 1951 Host: Anguilla dieffenbachii Gray, 1842; intestine. Specimen Deposited: U.S. Nat. Mus. Helminth. Collection No. 49158. Locality: Wellington. Family Acanthocolpidae 17. Stephanostomum pristis (Deslongchamps, 1824) Looss, 1899. Host: Physiculus bachus (Bloch & Schm.), red cod; intestine. Localities: Wellington, Portobello. Specimen Deposited: U.S. Nat. Mus. Helminth. Collection No. 49159. Discussion: A total of eight mature specimens were collected from three infected hosts. Measurements on four will show variations. Body length 4.172 to 5.838 mm.; width 0.420 to 0.490 mm. Forebody 0.630 to 0.980 mm.; post-testicular space 0.378 to 0.574 mm. Oral sucker 0.123 to 0.231 mm.; acetabulum 0.154 to 0.231 mm.; sucker ratio 1:1 to 1.25. Oral spines 36 to 42. Pharynx 0.177 to 0.192 mm. long by 0.154 to 0.177 mm. wide. Gonads are all separated by vitellaria. Cirrus sac extends about ⅓ distance from acetabulum to ovary. The vitellaria extend forward to the base of the cirrus sac or beyond as far as the middle of the sac. They are interrupted opposite the gonads although only slightly so opposite the ovary. Eggs are 57 to 72 by 26 to 40μ. It will be seen that these trematodes agree well with S. pristis, particularly the S. pristis of Lebour, 1908, except perhaps in sucker ratio which is reported as 1:1.5 for S. pristis and is only 1:1 to 1.25 in my specimens. A single egg measurement of 60 by 45μ is given for S. pristis probably for an uncollapsed

egg which in my specimens measured 68 by 45μ. It does not seem feasible to name a different species on the basis of these differences. S. pristis is reported from Gadus callarias and Gadus merlangus in Great Britain. Another species of Stephanostomum was collected together with S. pristis. Only one mature and one almost mature specimens were collected each from a different red cod. Both had lost all oral spines. Thus, an important specific character was missing. The chief difference between these specimens and S. pristis was the distribution of the vitellaria which overlapped the acetabulum slightly and were continuous without interruption opposite ovary and testes. The eggs were slightly larger and the cirrus sac reached halfway to the ovary. The pharynx was relatively small. The general appearance of this species is very much like that of S. triglae (Lebour, 1908) but the eggs are only 76μ long rather than 99μ. 18. Stephanostomuim australis n.sp. (Figs. 21–23) Host: Chelidonichthys kumu (Lesson and Garnot), gurnard; intestine. Locality: Wellington. Holotype: U.S. Nat. Mus. Helminth. Collection No. 49126. Description (based on 8 specimens with measurements on 6): Length 4.138 to 6.440 mm.; width 0.760 to 0.938 mm.; length 5.4 to 7 times greatest width. A specimen 1.946 mm. long was immature. Forebody 1.176 to 1.260 mm., from ¼ to ⅓ total body length. Posttesticular space 0.238 to 0.840 mm. Oral sucker much wider than long, 0.208 to 0.308 mm. wide; with 27 pairs of spines, total 54 (Fig. 21). Acetabulum 0.300 to 0.385 mm. wide. Sucker ratio 1:1.18 to 1.45. Prepharynx 0.385 to 0.616 mm. long; pharynx 0.200 to 0.292 mm. long by 0.192 to 0.269 mm. wide, oesophagus short; bifurcation shortly anterior to acetabulum; uroproct probably present but concealed by vitellaria. Testes elongate, close together in posterior third of body. Cirrus sac curving around right side of acetabulum, S-like, reaching 0.385 to 0.784 mm. posterior to acetabulum or less than halfway to ovary. Usually its extent was about ⅓ the distance to the ovary but in one case it was almost ½ while in a specimen with the cirrus protruded it was only about ⅙. Cirrus sac containing a slightly coiled seminal vesicle, a small ovoid prostatic vesicle, and a long armed cirrus. Ovary immediately anterior to anterior testis, not separated from it by vitellaria; slightly to the right. Vitellaria usually beginning at about level of middle of cirrus sac, rarely at base of cirrus sac, not reaching acetabulum; extending to posterior end of body; covering uterus dorsally and from base of cirrus sac halfway to ovary also ventrally; not meeting between gonads. Uterus with short coils; metraterm almost as long as cirrus sac. Eggs thin-shelled with pointed projection at anopercular end; 68 to 74 by 38 to 53μ. Excretory system not observed. The name australis is for the southern distribution of the species. Discussion: This species keys to Stephanostomum imparspine (Linton, 1905) Manter, 1940 in Caballero's (1952) key. It agrees with S. imparspine in most details but has a total of 54 oral spines rather than 33 to 34; the cirrus sac does not extend so far toward the ovary; and vitellaria dorsal to the uterus are not described for S. imparspine S. imparspine, however, is not very well described

and may prove to be the same as the New Zealand species. It is reported from such a variety of hosts (16) at Woods Hole, Massachusetts and Beaufort, North Carolina that perhaps more than one species were included in it. S. anisotremi Manter, 1940 is similar to S. australis in many respects but has a sucker ratio of 1:2, the vitellaria do not cover the uterus dorsally, and there are 40 rather than 54 oral spines. S. baccatum (Nicoll, 1907) Manter, 1934 has 54 oral spines but has a short cirrus sac and larger eggs. Differentiation of species in the rather large genus Stephanostomum is still rather unsatisfactory although Caballero (1952) has compiled the literature and clarified some confusion. The number of oral spines seems to be relatively constant in a species, varying by not more than two to four, if at all, but these spines are difficult to count accurately in many specimens. Some descriptions even of long established species are based on one or two specimens. More information regarding variation is needed, for example, for S. triglae and S. baccatum. On the other hand, Linton probably had more than one species under the name of S. tenue (Linton, 1898) Linton, 1940 and S. dentatum (Linton, 1900). In the face of these difficulties, any key to species is more or less unsatisfactory and no attempt will be made here to improve the one in Caballero (1952). Caballero considers S. sentum Linton, 1910 to be a synonym of S. minutum (Looss, 1901) and names S. lebourae for the S. caducum (Looss, 1901) of Lebour, 1908. He recognises 29 species in the genus. Family Opecoelidae 19. Opecoelus lotellae n.sp. (Figs. 24–26) Host: Lotella rhacinus (Forster), Southern hake; intestine. Locality: Wellington. Holotype: U.S. Nat. Mus. Helminth. Collection No. 49127. Description (based on 25 specimens with measurements on six): Body elongate, 1.160 to 2.702 mm. long by 0.392 to 0.518 mm. wide; greatest width at acetabular level. Acetabulum protrusible and retractile, with four or five pairs of short, blunt papillae inconspicuous when retracted, short, rounded and bilobed (Fig. 25) when extended. Probably five occur on each lip but sometimes only four on one lip or the other can be counted. Oral sucker 0.131 to 0.169 mm. wide; acetabulum wider than long, 0.231 to 0.287 mm. wide. Sucker ratio 1:1.7 to 1.88. Forebody more or less contractile, 0.392 to 0.518 mm. long or about 1/5 body length. Posttesticular space 0.658 to 0.760 mm., considerably longer than forebody. Short prepharynx present; pharynx 0.057 to 0.114 mm. long by 0.057 to 0.102 mm. wide; oesophagus 0.046 to 0.099 mm. long; bifurcation about midway between suckers; anus ventral a short distance anterior to posterior end of body. The genital pore is to left of midline at level of the oesophagus, rarely it is slightly posterior to the oesophagus or it can be near the anterior end of the oesophagus. Testes smooth, ovoid, longer than wide, tandem, in third fourth of body, separated by a few vitelline follicles. Seminal vesicle sinuous, extending almost halfway, or rarely halfway, between acetabulum and ovary. Cirrus sac (Fig. 26) more or less spindle shaped, 0.095 to 0.114 by 0.046 to 0.057 mm.,

rather thick-walled; containing a well developed, muscular cirrus, a small, ovoid pars prostatica, a short tubular portion of the seminal vesicle and a few gland cells. Ovary ovoid to subtriangular, median, a short distance pretesticular. Uterine seminal receptacle, large preovarian Mehlis' gland present; metraterm about same length as cirrus sac, glandular in posterior half. Eggs 53 to 60 by 26 to 30μ. Vitelline follicles begin slightly anterior to ovary and extend without interruption to near posterior end of body; they extend medianly but do not meet between ovary and testes, they usually meet between the testes, and fill most of the posttesticular space. In some specimens, they begin at level of the ovary and in none do they reach halfway between ovary and acetabulum, and in none do they reach the seminal vesicle. Excretory pore terminal; excretory vesicle extending dorsal to testes to the ovary or to Mehlis' gland. Discussion: This species is clearly most like O. sphaericus Ozaki, 1925 from Conger myriaster and Hexagrammos otakii in Japan, which, however, has three pairs of papillae on the acetabulum. There are several other small differences: O. sphaericus is larger; its eggs 72 to 81 by 14 to 47μ compared with 53 to 60 by 26 to 30μ; its vitellaria extend halfway between ovary and acetabulum; its seminal vesicle is straight and shorter; its ovary more lobed. O. lotellae is more like O. adsphaericus Manter and Van Cleave, 1951 in body size and egg size but differs in having more than three pairs of acetabular papillae; in larger sucker ratio; in uninterrupted vitellaria which also do not extend so far forward. The anterior extent of the vitellaria in O. adsphaericus was erroneously described as “varying from base of cirrus sac to posterior edge of acetabulum.” The correct statement should be: varying from base of seminal vesicle to posterior edge of acetabulum. The lobed shape of the acetabular papillae is unlike any species of Opecoelus except O. elongatus which has only two pairs and has deeply lobed testes and ovary. The only other species of Opecoelus with four or five pairs of papillae are O. goniistii Yamaguti, 1938 and O. mexicanus Manter, 1940. The former has a bilobed ovary, contiguous testes, and more anterior extent of vitellaria. The latter has rather long, pointed papillae, vitellaria to the acetbulum, and contiguous gonads. Opegaster pentedactyla Manter, 1940 and O. acuta Manter, 1940 have five pairs of papillae but the seminal vesicle does not extend posterior to the a acetabulum, the oral sucker and pharynx are relatively larger. The genus Opegaster is so similar to Opecoelus that if retained it must be distinguished on some arbitrary basis. There are so many species in the two genera that it seems desirable to retain them both if possible. It is suggested to utilize the anterior extent of the vitellaria to separate the genera; Opegaster with vitellaria extending to anterior edge of acetabulum or (usually) beyond; Opecoelus with vitellaria not reaching anterior edge of acetabulum. Gland cells or “rudimentary vitellaria” not containing yolk granules are not considered as vitellaria. This classification implies that the great variation in anterior extent of vitellaria noted by Tubangui and Masilungan (1944) in “Opegaster minimus (Tubangui, 1928)” involves more than one species. On this basis, the genus Opecoelus includes the following species. O. acutus (Manter, 1940) n. comb. (synonym: Opegaster acutus Manter, 1940); O. adsphaericus Manter & Van Cleave, 1951 O. elongatus Ozaki, 1925; O. goniistii Yamaguti, guti, 1938; O. inimici Yamaguti, 1934; O. lobatus Ozaki, 1925; O. minimus

Tubangui, 1928 (synonym: Opegaster minimus [Tubangui, 1928] Yamaguti, 1934); O. minor Yamaguti, 1934; O. mexicanus Manter, 1940; O. mutu Yamaguti, 1940; O. ozakii (Layman, 1930) Yamaguti, 1938; O. pentedactylus (Manter, 1940) n. comb. (synonym: Opegaster pentedactyla Manter, 1940); O. quadratus Ozaki, 1928; O. sphaericus Ozaki, 1925 (type species, synonym: O. sebastodis Yamaguti, 1934); O. tasmanicus Crowcroft, 1947; and O. xenistii Manter, 1940. Of these species, O. mutu does not seem to differ significantly from O. lobatus and it is here considered a synonym, reducing the number of species to fifteen. The following key is proposed to separate these species of Opecoelus. Key To Species Of Opecoelus 1 (8) With lobed testes 2 2 (3) Vitellaria not extending anterior to ovary O. elongatus Ozaki, 1925 3 (2) Vitellaria extending anterior to ovary 4 4 (7) Five or six pairs of acetabular papillae 5 5 (6) Seminal vesicle extending posterior to testes O. xenislii Manter, 1940 6 (5) Seminal vesicle not extending posterior to testes O. tasmanicus Crowcroft, 1947 7 (4) Three pairs of acetabular papillae O. lobatus Ozaki, 1925 (synonym: O. mutu Yamaguti, 1940) 8 (1) With unlobed testes 9 9 (18) With four or five pairs of acetabular papillae 10 10 (13) Vitellaria not reaching acetabulum. 11 11 (12) Testes contiguous; ovary bilobed O. goniistii Yamaguti, 1938 12 (11) Testes not contiguous; ovary not bilobed O. lotellae (this paper) 13 (10) Vitellaria reaching acetabulum 14 14 (15) Genital pore opposite prepharynx O. acutus (Manter. 1940) 15 (14) Genital pore posterior to prepharynx 16 16 (17) Three median papillae longer O. mexicanus Manter, 1940 17 (16) All papillae small O. penledactylus Manter, 1940 18 (9) With three pairs of acetabular papillae (or none described) 19 19 (20) Ovary 4-lobed O. quadratus Ozaki, 1928 20 (19) Ovary not 4-lobed 21 21 (22) Seminal vesicle not extending posterior to acetabulum O. minimus Tubangui, 1928 22 (21) Seminal vesicle extending posterior to acetabulum 23 23 (26) Gonads contiguous 24 24 (25) Papillae not observed O. ozakii (Layman, 1930) 25 (24) Three pairs rather long papillae O. inimici Yamaguti, 1940 26 (23) Gonads not contiguous 27 27 (28) Papillae very long O. minor Yamaguti, 1934 28 (27) Papillae short 29 29 (30) Vitellaria usually interrupted opposite testes, eggs 49–59 by 25–38μ O. adsphaericus Mantel & Van Cleave, 1951 30 (29) Vitellaria not usually interrupted opposite testes; eggs 72–81 by 44–47μ O. sphaericus Ozaki, 1925

20. Opegaster gobii Yamaguti, 1952 (Fig. 27) Host. Unidentified species of Tripterygion, blenny; intestine. Locality: Wellington. Specimen Deposited: U.S. Nat. Mus. Helminth. Collection No. 49160. Discussion: Nine specimens were collected. These agreed with O. gobii in size, sucker ratio, and extent of excretory vesicle. The three pairs of acetabular papillae are very small, sometimes not observable. The genital pore, although sometimes submedian, could be more than halfway to the left edge of the body. The cirrus sac is inconspicuous. Sucker ratio was 1:1.33 to 1.5 rather than 1:1.5 to 1.7, and eggs were 57 to 65 by 34 to 38μ rather than 63 to 76 by 45 to 51μ. The greatest difference appears to be in width of the eggs but in the absence of other distinctions, I am considering these trematodes as O. gobii. Yamaguti collected his material from Gobius sp. at Macassar in the Celebes. 21. Opegaster caulopsettae n. sp. (Figs. 28–29) Host: Caulopsetta scapha (Forster), threadfin flounder; intestine. Locality: Wellington. Holotype: U.S. Nat. Mus. Helminth. Collection No. 49128. Description (based on a single specimen): Length 3.500 mm.; width, greatest near acetabular level, 0.784 mm., body tapering almost to a point at each end. Forebody 0.462 mm or only about 1/7 body length. Pretesticular space very long, 1.400 mm. or 0.4 of total body length. Oral sucker 0.185 mm. wide; acetabulum 0.416 mm. wide; sucker ratio 1:2.17. Acetabular papillae lacking. Prepharynx lacking; pharynx 0.091 mm. long by 0.092 mm. wide; oesophagus 0.102 mm. long; bifurcation slightly preacetabular; caeca seemingly uniting near posterior end of body and opening dorsally through an anus just anterior to the excretory pore near posterior end of body (Fig. 29). Genital pore to left opposite base of oral sucker. Testes deeply lobed, tandem, approximately at midbody; separated by a short space. Cirrus sac short, cylindrical, muscles mostly longitudinal; pars prostatica much reduced or absent; seminal vesicle entirely external, tubular, sinuous, extending about ⅓ distance from acetabulum to ovary. Ovary deeply 3-lobed, median, a short distance anterior to testes; seminal receptacle lacking. Vitellaria from anterior edge of acetabulum (slightly beyond in the left side) continuous to near posterior end of body, inserted somewhat between gonads but not confluent medianly except posterior to testes, filling most of posttesticular space; dorsal, ventral, and lateral to caeca. Metraterm not observed. Eggs 65 to 68 by 34μ. Excretory pore dorsal, near posterior end of body; excretory vesicle extending to the ovary. Discussion: Generic identification in the Opecoelinae may depend on the ending of the intestinal caeca. Whether these caeca end blindly, or end in ani or an anus, are sometimes difficult points to determine without serial sections. If one of the dorsal pores near the posterior end of the body (Fig 29) is not an anus and the caeca end blindly this species would be a member of the genus Pseudopecoelus. Assuming the anus, it resembles Opecoelina except for the lack of a seminal receptacle.

Fig. 24—Opecoelus lotellae from Lotella rhacinus Ventral view. Fig. 25—Papillae on anterior half of acetabulum of O. lotellae. Lateral view. Fig. 26—Terminal genital organs of O. lotellae. Ventral view. Fig. 27—Opegaster gobii from a blenny. Ventral view. Fig. 28—Opegaster caulopsettae from Caulopsetta scapha. Ventral view Fig. 29—Posterior end of O. caulopsettae. Dorsal view to show anus and excretory pore. Fig. 30—Pseudopecoelus hemilobatus from Cyttus australis. Ventral view. Fig. 31—Acetabulum of P. hemilobatus showing papillae. Lateral view.

The species appears to be most like Opegaster tamori Yamaguti, 1938 from Hapalogenys mucronatus in the East China Sea. It differs chiefly in much more anterior genital pore. In addition, the gonads are not so close together, the testes and ovary more deeply lobed, the posttesticular space longer. Most species of Opegaster have more anterior extension of the vitellaria and unlobed ovary and testes. 22. Pseudopecoelus vulgaris (Manter, 1934) Von Wicklen, 1946 Synonym: Cymbephallus vulgaris Manter, 1934 Host: Helicolenus percoides Richardson, sea perch; intestine and caeca. Locality: Portobello. Specimen Deposited. U.S. Nat. Mus. Helminth. Collection No. 49161. Discussion: Four specimens were collected. They agree in almost all respects with P. vulgaris from sixteen different species of deepwater fishes at Tortugas, Florida, and particularly with a few specimens of P. vulgaris from Helicolenus dactylopterus in which the vitellaria are interrupted opposite the gonads. The only difference of possible significance is that the testes of the New Zealand specimens are not lobed except for a few slight irregularities. However P. vulgaris, as noted in its description, is rather variable and the specimens from Helicolenus in Florida show less lobing of the testes than usual. One of the most striking characters of this species is the very large egg size (nearly the size of the pharynx). Eggs in New Zealand specimens were 91 to 118 by 53 to 65μ being usually about 100μ long as in the Florida material. Such details as sucker ratio, length of oesophagus, position of genital pore, character of cirrus and seminal vesicle are the same in both collections. In many specimens of P. vulgaris it is not possible to determine whether the caeca end blindly or unite with the excretory vesicle. The point could not be determined for the specimens from H. dactylopterus. I have previously noted (Manter, 1934, p. 295) the interesting bathymetric distribution of P. vulgaris at Tortugas. It was never collected from shallow water fishes; first appearing at about 60 fathoms, it becomes very common in many species of fishes at 100 fathoms and below so far as collections were made (316 fathoms). Its occurrence in New Zealand is another example of the far flung distribution of these cold water species of trematodes which, while not able to infect warm-water fishes a few fathoms above them, can be found in cold waters of either the northern or southern hemispheres thousands of miles away. Helicolenus is not typically a shallow-water fish but it does appear in quantity in the dredges of commercial fishermen off Campbell Point, an evidence of the proximity of deep water and the upwelling movements of oceanic waters in this region. 23. Pseudopecoelus hemilobatus n.sp. (Figs. 30–31) Host: Cyttus australis (Richardson), boar fish; intestine. Locality: Portobello. Holotype. U.S. Nat. Mus. Helminth. Collection No. 49129. Description (based on two specimens and fragments of two others): Body unspined, elongate, forebody tapering, posterior end broadly rounded and only slightly tapered. Length 2.570 to 2.940 mm., greatest width near midbody

0.658 to 0.795 mm. Oral sucker 0.169 to 0.231 mm. wide, somewhat longer than wide when extended; acetabulum 0.369 to 0.455 mm. wide, slightly wider than long. Sucker ratio 1:2 to 2.2. Acetabulum only slightly protuberant, with narrow transverse aperture; upper lip without papillae; posterior lip with one pair of short muscular papillae and a single, median, bilobed, non-muscular papilla (Fig. 31). Forebody 0.672 to 0.728 mm., varying with contraction from about ⅙ to slightly more than ¼ total body length. Prepharynx lacking; pharynx 0.133 to 0.161 mm. long by 0.102 to 0.107 mm. wide; oesophagus 0.246 to 0.285 mm. or from 1 ½ to 2X length of pharynx; bifurcation just anterior to acetabulum; caeca extending to near posterior end of body where each ends blindly. Genital pore a little to left of midline, opposite posterior half of pharynx or a little posterior to pharynx. Testes large, tandem or slightly diagonal, in posterior half of hindbody, wider than long, filling intercaecal space, close together, usually slightly bilobed; posttesticular space 0.504 to 0.560 mm. Cirrus very short; cirrus sac lacking; prostatic vesicle elongate, about 0.152 by 0.018 mm.; seminal vesicle tubular, becoming sinuous posterior to acetabulum, extending more than halfway between acetabulum and ovary (0.121 to 0.152 mm. from ovary). Ovary rather deeply trilobed with some secondary lobing. Seminal receptacle lacking. Mehlis' gland dorsal to first part of uterus just anterior to ovary; uterus preovarian; metraterm weakly muscular about ⅔ length of prostatic vesicle. Vitelline follicles fairly large, beginning opposite middle of acetabulum on the right, at posterior edge of acetabulum on the left, extending unbroken to near posterior end of body, dorsal and ventral to caeca, not meeting between gonads. Eggs 68 to 71 by 39 to 44μ. Excretory pore terminal; extent of vesicle not observed. Numerous gland cells occur in the forebody near the ventral surface just anterior to the acetabulum. These are not vitellaria-like. A transverse groove in the ventral surface just anterior to the acetabulum might be more than a fold but its aperture does not have a definite boundary nor musculature. An accessory sucker is absent. The name hemilobatus is from hemi, half, and lobatus, lobed and refers to the papillae being limited to the posterior half of the acetabulum. Discussion: This species is placed in the genus Pseudopecoelus because the caeca end blindly, and an accessory sucker is lacking. However, Pseudopecoelus supposedly lacks acetabular papillae whereas they occur in P. hemilobatus but only on the posterior lip of the acetabulum. In this respect, P. hemilobatus differs from all the other seven species in the genus. Otherwise it appears to be most like P. japonicus (Yamaguti, 1938) Von Wicklen, 1946 from mostly deepwater fishes of Japan, differing chiefly in the sucker ratio. The specimen identified as P. japonicus from Centriscops humerosus from Portobello is very similar to P. hemilobatus. However, it showed no papillae or lobes on the acetabulum although a central posterior portion was everted. Other differences are shorter prostatic vesicle, shorter oesophagus, more lobed testes, more anterior extent of the vitellaria, wider and larger oral sucker. It must be admitted that some of these differences are not great and may be partly due to contraction; but in view of the apparent absence of acetabular papillae, the two species are considered different at least for the present.

Key To The Species Of Pseudopecoelus 1 (8) Ovary lobed 2 2 (3) Papillae on posterior lip of acetabulum P. hemilobatus 3 (2) No papillae on lips 4 4 (5) Vitellaria extending anterior to acetabulum P. umbrinae Manter and Van Cleave, 1951 5 (4) Vitellaria not extending anterior to acetabulum 6 6 (7) Acetabulum 2× to 3× oral sucker P. vulgaris (Manter, 1934) Von Wicklen, 1946 7 (6) Acetabulum only slightly larger than oral sucker P. japonicus (Yamaguti. 1938) Von Wicklen, 1946 8 (1) Ovary unlobed 9 9 (10) Vitellaria extending anterior to acetabulum P. gibbonsiae Manter and Van Cleave, 1951 10 (9) Vitellaria not extending anterior to acetabulum 11 11 (12) Vitellaria interrupted opposite gonads P. elongatus (Yamaguti, 1938) Von Wicklen, 1946 12 (11) Vitellaria not interrupted opposite gonads 13 13 (14) Acetabulum notched laterally P. priacanthi (MacCallum, 1921) Manter, 1947 14 (13) Acetabulum not notched laterally 15 15 (16) Testes not indented; eggs 44 to 51μ long P. barkeri Hanson, 1950 16 (15) Testes somewhat indented, eggs 57 to 66μ long P. torugae Von Wicklen, 1946 24. Pseudopecoelus japonicus (Yamaguti, 1938) Von Wicklen, 1946 (Figs. 32–33) Host: Centriscops humerosus (Richardson), bellows fish; intestine. Locality: Portobello. Specimen Deposited: U.S. Nat. Mus. Helminth. Collection No. 49162. Discussion: A single specimen of this trematode was collected. It resembles P. vulgaris except in egg size, the chief difference which Yamaguti used to distinguish his P. japonicus collected from eleven species of deepwater fishes in Japan. My specimen differs from Yamaguti's description in that the testes are deeply lobed rather than “indented”; both suckers are relatively larger; and the uterus is shorter. Since these are characters probably varying with age and contraction, and only one specimen was available, it is considered to be P. japonicus with which it agrees in such characters as sucker ratio, position of genital pore, extent of vitellaria, egg size, and shape of ovary. It resembles P. vulgaris particularly in shape of the gonads but the egg size is much smaller and the sucker ratio different. Measurements were: size 1.540 by 0.539 mm., but somewhat contracted; fore-body 0.277 mm., oral sucker 0.192 mm. wide; acetabulum 0.254 mm. wide; sucker ratio 1:1.32; pharynx 0.099 by 0.099 mm.; oesophagus 0.095 mm long; caeca ending blindly near posterior end of body; eggs 70 to 72 by 34 to 38μ.

Fig. 32—Pseudopecoelus japonicus from Centiciscops humerosus. Ventral view. Fig. 33—Terminal genital organs of P. japonicus. Ventral view. Fig. 34—Plagioporus preporus from Chelidonichthys kumu. Ventral view. Fig. 35—Plagioporus dactylopagris from Dactylopagrus macropterus. Ventral view. Fig. 36—Plagioporus interruptus from Pseudolabrus coccineus Partly ventral view of twisted specimen. Fig. 37—Terminal genital organs of P. interruptus Ventral view.

25. Pseudopecoeloides tenuis Yamaguti, 1940 Host: Trachurus novae-zelandiae (Richardson), horse mackerel; stomach, intestine and caeca. Locality: Wellington. Specimen Deposited: U.S. Nat. Mus. Helminth. Collection No. 49163. Discussion: Six specimens of this thread-like trematode were collected. They agreed almost perfectly with Yamaguti's P. tenuis reported from Pseudopriacanthus nipponicus in Japan. Egg size in my material was 49 to 68 by 34μ, extending variation in length somewhat; uncollapsed eggs were relatively wider than indicated by Yamaguti's measurements. Pseudopecoelus gracilis Manter, 1947 from Trachurops crumenophthalma at Tortugas has a much larger acetabulum; P. carangi (Yamaguti, 1938) Yamaguti, 1940 from Caranx mertensi in Japan has uninterrupted vitellaria. Yamaguti (1953) reports P. tenuis from Priacanthus hamrur at Macassar, Celebes. 26. Plagioporus preporatus n.sp. (Fig. 34) Host: Chelidonichthys kumu (Lesson and Garnot), gurnard; intestine. Locality: Portobello. Holotype: U.S. Nat. Mus. Helminth. Collection No. 49130. Description (based on one specimen): Length 2.100 mm.; width 0.630 mm. at level of acetabulum; body tapering toward each end, almost pointed posteriorly. Oral sucker 0.160 mm. wide; acetabulum wider than long, 0.369 mm. wide Sucker ratio 1:2.3. Forebody 0.447 mm. Short prepharynx; pharynx 0.106 mm. long by 0.076 mm. wide; oesophagus about same length as pharynx; bifurcation about midway between suckers; caeca extending past testes but ending some distance (about 0.350 mm.) from posterior end of body. Testes tandem, lobed, close together; anterior testis just posterior to midbody. Genital pore to the left, far forward, at a level just posterior to middle of oral sucker. Cirrus sac almost straight, claviform, extending diagonally backward to the mid-anterior edge of the acetabulum. Seminal vesicle tubular, somewhat coiled, in posterior half of cirrus sac. Cirrus weakly developed, with a few gland cells. Ovary unlobed, longer than wide, extending diagonally backward to overlap the right side of anterior testis. Seminal receptacle dorsal to anterior half of ovary. Vitelline follicles large, from posterior edge of pharynx to within a short distance of posterior end of body; continuous; dorsal, lateral, and ventral to caeca; confluent dorsally and almost so ventrally anterior to acetabulum. Uterus partly to left of ovary, mostly preovarian; eggs 76 by 42μ. Excretory pore terminal; excretory vesicle can be traced only to the posterior testis. The name preporatus is for the far forward location of the genital pore. Discussion: This species differs from all the others in the genus Plagioporus in having the genital pore opposite the oral sucker. It is probably most like P. japonicus Yamaguti, 1938 but the genital pore is more anterior, the testes tandem and more lobed. From P. branchiostegi Yamaguti, 1937 it differs in the same respects and in that the cirrus sac does not overlap the acetabulum P. lobatus (Yamaguti, 1934) is reported from Chelidonichthys kumu in Japan. It

differs in having a lobed ovary and a genital pore well posterior to the oral sucker. Plagioporus is a very large genus and will be discussed below. 27. Plagioporus dactylopagri n.sp. (Fig. 35) Host: Dactylopagrus macropterus (Forster), tarakihi; intestine. Locality: Portobello. Holotype: U.S. Nat. Mus. Helminth. Collection No 49131. Description (based on two specimens, one extended, the other [Fig. 35] moderately contracted): Length 1.432 to 1.834 mm.; anterior end rounded; posterior end not tapered, subtruncate. Greatest width 0.385 to 0.672 mm. near acetabular level but most of body almost equally wide. Forebody 0.455 to 0.462 mm. or about ⅓ to ¼ body length. Oral sucker 0.161 to 0.231 mm. wide; acetabulum slightly wider than long, 0.269 to 0.369 mm. wide. Sucker ratio 1:1.6 to 1.66. Pharynx 0.125 by 0.125 mm. in the 1.834 mm. specimen. Oesophagus not observed, probably very short. Caeca extending slightly past testes to posterior end of body. Genital pore to left of oral sticker; in one case almost at mid-sucker level, in the other (extended specimen) it is very inconspicuous but judging partly from the location of the prostatic vesicle, it lies to the left of posterior fifth of oral sucker. Testes smooth, subspherical, tandem, in posterior third of body, close together, large, filling intercaecal space. In one specimen (Fig. 35) the posterior testis was partially degenerate. Posttesticular space short, 0.154 to 0.269 mm. or about 1/7 to ⅛ body length. Cirrus sac claviform. curving from the right anterior edge of acetabulum to genital pore; containing a tubular seminal vesicle looped once, an ovoid prostatic vesicle the base of which is a little posterior to middle of the sac, a rather long cirrus, and a few prostatic cells. Ovary transversely ovoid, smooth, immediately pretesticular, slightly to the right. Vitelline follicles large, extensive, from posterior third of oral sucker or from midpharynx level to extreme posterior end of body; confluent dorsally in forebody and posterior to testes; dorsal, ventral and lateral to caeca. In both specimens, the vitelline follicles were interrupted briefly opposite the acetabulum on the left side only. Uterus pretesticular, with a few wide coils. A thin-walled claviform metraterm about half as long as the cirrus sac could be seen in one specimen. Under high power, an appearance of fairly long fine spines near the base of the metraterm was seen but it hardly seems possible that such spines could be present. Eggs 44 to 47 by 24 to 27μ. Excretory system not observed. Discussion: Of the numerous species named in the genus Plagioporus only P. preporatus has the genital pore so far anterior. But P. preporatus is very different in its long posttesticular space, tapered posterior end, sucker ratio lobed testes, and smaller eggs. The most closely related species seem to be P. pacificus Yamaguti, 1938; P. ira Yamaguti, 1940; P. japonicus Yamaguti, 1938; P. calotomi (Yamaguti, 1934); and P. isaitschikowi (Layman, 1930) all from the North Pacific. In all of these the genital pore is rather far forward although not reaching the oral sucker. In most of them the eggs are much larger (57 to 90μ long) while in P. pacificus and P. calotomi the eggs are much smaller (24 to 31μ long).

28. Plagioporus interruptus n.sp. (Figs. 36–37) Host: Pseudolabrus coccineus (Forster), soldier fish; intestine. Localities: Wellington; Portobello. Holotype: U. S. Nat. Mus. Helminth. Collection No. 49132. Description (based on five specimens): Two specimens were collected from a Pseudolabrus species, probably coccineus, at Portobello and three specimens from P. coccineus at Wellington. The latter specimens were smaller in size (not over 1.347 mm.) and somewhat macerated; but body proportions and egg size were similar to the two larger specimens from Portobello, the smallest of which was 1.794 mm. Length 1.116 to 1.925 mm.; greatest width at acetabular level, 0.207 to 0.455 mm. Anterior end broadly rounded; forebody 0.377 to 0.662 mm., usually about ⅓ total body length but up to over 39%. Hindbody tapering to the almost pointed posterior end. Oral sucker 0.121 to 0.231 mm. in transverse diameter; acetabulum 0.181 to 0.385 mm., slightly wider than long, with transverse aperture. Sucker ratio 1: 1.5 to 1 66. Prepharynx very short or lacking; pharynx in the 1.925 mm. specimen 0.076 mm. long by 0.057 mm. wide. Oesophagus short; bifurcation nearer to oral sucker than to acetabulum; caeca extending well past testes but not to posterior end of body. Genital pore slightly to the left at level of oesophagus or posterior end of pharynx. Testes smooth, tandem, large, close together, in middle of hindbody. Posttesticular space 0.200 to 0.462 mm. Cirrus sac (Fig. 37) large, with two curves in its anterior half, extending obliquely to the right slightly past the anterior level of acetabulum but not overlapping the acetabulum itself (Fig. 37). It contains a long tubular, coiled, seminal vesicle in its basal half, followed by a tubular prostatic vesicle then a long pars prostatica with few prostatic cells, and a short, thick-walled cirrus. Ovary ovoid, slightly to the right, immediately anterior to testes. To the left of the ovary is a ventral compact Mehlis' gland and a dorsal seminal receptacle. Uterus preovarian. Metraterm thin-walled with a few gland cells, about length of cirrus sac. Eggs 19 to 34 by 11 to 14μ, usually 20 to 25 by 12 to 14μ. Vitelline follicles numerous in forebody from middle of oral sucker to a little past anterior edge of acetabulum; contiguous dorsally; interrupted opposite acetabulum; lateral from acetabulum to anterior testis; interrupted opposite testes; usually filling most of the posttesticular space. Discussion: This species is unique in the genus in that the vitelline follicles are interrupted both opposite the acetabulum and the testes. It has much smaller eggs than most species, exceptions being P. choerodonis (Yamaguti, 1934) Yamaguti, 1938; P. calotomi (Yamaguti, 1934) Yamaguti, 1938; and P. pacificus Yamaguti, 1938. It is probably most similar to P. choerodonis (from Choerodon azurio in Japan) which has the vitellaria interrupted opposite the acetabulum but not opposite the testes. Also, P. choerodonis differs in having a wide, slightly lobed ovary, and a very short posttesticular space. P. calotomi has continuous vitellaria and the uterus overlaps the anterior testis. In P. pacificus, the vitellaria are not interrupted opposite the testes, do not extend so far anteriorly, and the seminal vesicle is less coiled. P. isaitschikowi (Layman, 1930) Price. 1934 has vitellaria interrupted opposite the acetabulum but its eggs are much larger.

29. Plagioporus (Caudotestis) pachysomus n.sp. (Fig. 38) Hosts: Parapercis colias (Forster), blue cod, type host Cyttus australis (Richardson), boar fish. Locality: Portobello. Holotype: U.S. Nat. Mus. Helminth. Collection No. 49133. Description (based on five specimens): Body robust, ovate, tapering about equally from midbody to bluntly rounded ends; length 2.450 to 2.996 mm., greatest width 0.938 to 1.120 mm. Cuticula thick, tending to be somewhat rugose. Forebody 0.812 to 1.092 mm., posttesticular space very short, 0.196 to 0.336 mm. Oral sucker 0.223 to 0.254 mm. wide; acetabulum near midbody, wider than long, 0.431 to 0.478 mm. wide. Sucker ratio 1:1.56 to 2 Strong radiating muscles extend from the acetabulum in the body wall. Prepharynx very short, pharynx 0.138 to 0.160 mm. long by 0.123 to 0.154 mm. wide; oesophagus 0.060 to 0.138 mm., shorter than pharynx; bifurcation about ⅓ distance from oral sucker to acetabulum; caeca ending blindly opposite, and often dorsal to, middle of posterior testis. Genital pore to the left opposite pharynx or as far forward as basal half of oral sucker. Testes large, unlobed, tandem or slightly diagonal, close together, seemingly pressed into subtriangular shapes; filling most of the body width so that both vitellaria and caeca tend to become dorsal opposite them. Cirrus sac very large, 0 631 to 1.078 mm. long by 0.231 to 0.254 mm. wide, straight, bent, or sinuous, extending diagonally backward to overlap the left anterior edge of acetabulum, reaching almost to midacetabular level; containing a coiled tubular seminal vesicle an elongate pars prostatica, and a long cirrus. Cirrus often protruded; when retracted it is somewhat sinuous in the cirrus sac. Ovary deeply 3– or 4-lobed, to the right, immediately anterior to anterior testis. Large seminal receptacle to left of ovary. Uterus mostly to left of ovary, between anterior testis and acetabulum; metraterm well developed, almost as long as cirrus sac. Eggs small, only 21 to 25 by 11 to 13μ. Vitelline follicles large, from level of pharynx to slightly beyond testes, mostly dorsal; filling most of forebody dorsal to caeca and cirrus sac, also lateral to caeca and dorsal to testes but less numerous posterior to acetabulum, extending posterior to ends of caeca but usually not quite contiguous posterior to testes. Excretory pore terminal; anterior extent of vesicle not determined. Discussion: The subgenus Caudotestis was named by Isaitschikow in 1928. It was raised to generic rank by Yamaguti (1934). It differed from Plagioporus chiefly in that the caeca did not extend posterior to the testes. While such a character is a small one for generic differentiation it does characterize a number of species mostly from fresh-water fishes. It would serve to reduce the large number of species in Plagioporus. However, Miller (1941) and Prudhoe (1945) do not recognize Caudotestis as a genus and Yamaguti himself (1951, p. 253) now considers it a subgenus. In view of this attitude of recent authors, it is here considered a subgenus. The following species belong in this subgenus: P. angulatus (Dujardin, 1845) Szidat, 1944; P. azurionis Yamaguti, 1951; P. cooperi (Hunter and Bangham, 1932) Price, 1934; P. dorosomatis Yamaguti, 1951; P. fusiforme Price, 1934; P. gnathopogonis (Yamaguti, 1934) Yamaguti, 1953, P. nicolli (Isaitschikow, 1928) Yamaguti, 1953; P. orientalis (Yamaguti, 1934) Yamaguti,

Fig. 38–Plagioporus (Caudotestis) pachysomus from Cyttus australis. Ventral view. Fig. 39—Podocotyle caithnessi from Leptocephalus conger. Ventral view. Fig. 40—Cirrus sac of P. caithnessi. Fig. 41—Helicometia magnora from Chelidonichthys kumu. Ventral view. Fig. 42—Cirrus sac of H. magnora. Ventral view. Fig. 43—Coitocaecum tylogonium from Centriscops humerosus. Ventral view Fig. 44—Decemtestis pseudolabri from Pseudolabrus celidotus. Dorsal view.

1953; P. protei Prudhoe, 1945; P. sinitsini Mueller, 1934; P. spari Yamaguti, 1951; P. synagris Yamaguti, 1952; P. thalassomatis (Yamaguti, 1942) Yamaguti, 1953; P. pachysomus this paper; P. zacconis (Yamaguti, 1934) Yamaguti, 1953. P. pachysomus has very small eggs for the subgenus, a size approached only by P. neopercis and P. thalassomatis. From both of these P. pachysomus differs in its lobed ovary, larger cirrus sac, and more anterior genital pore. It should be noted that the single specimen of P. pachysomus from Cyttus australis was found in a host examined immediately after several specimens had been collected from Parapercis colias. Under these conditions a contamination of pipette or glassware is possible and the collection supposedly from Cyttus may have originated in Parapercis. Because of this possibility this specimen (Fig. 38) is considered a paratype and another from Parapercis the holotype. The Genus Plagioporus Stafford, 1904 The genus Plagioporus Stafford, 1904 (= Lebouria Nicoll, 1909) is a large one; at least 43 species have been named in it. It is one of the few genera of trematodes in both marine and freshwater fishes. The similarity of the genera Plagioporus, Podocotyle, and Hamacreadium has been discussed by Manter (1947). In practically all species of Plagioporus the vitellaria extend anterior to the acetabulum although not much so in P. cooperi (Hunter and Bangham, 1932) The genital pore is sinistral. The ovary is lobed in only a few species; the testes, usually tandem, can be diagonal. The following changes are proposed with the intent of clarifying the genus. It is recommended that P. crassigulus (Linton, 1910) Price, 1934 and P. gastrocotylus Manter, 1940 be removed to a new genus, Pachycreadium, with the following characters: Pachycreadium n.gen. Body thick and stout with strong suckers and large pharynx. Body musculature around acetabulum strongly developed and may form a fold of skin. Oesophagus short; caeca wide. Genital pore median or submedian, not far from intestinal bifurcation. Testes postovarian, unlobed, tandem or diagonal, close together. Cirrus sac with sinuous seminal vesicle, overlapping anterior half of acetabulum. Ovary unlobed, slightly dextral. Vitellaria profuse, from region of pharynx to posterior end of body, contiguous posterior to testes. Uterus partly to left of ovary and extending backward to posterior edge of anterior testis. Type species: P. gastrocotylum (Manter, 1940) n. comb. Other species P. crassigulum (Linton, 1910) n. comb. Pachycreadium differs from Plagioporus in more median genital pore, thick body, large pharynx, and in the muscular development of the body wall near the acetabulum. Also, the uterus extends more posteriorly Both of the species are from marine fishes of the genus Calamus; one is at Tortugas, Florida; the other at the Galapagos Islands. Although as noted (Manter, 1940) these trematodes show similarity to the Fellodistomatidae they are retained for the present in the Opecoelidae. Seventeen species of Plagioporus in the subgenus Caudotestis have been discussed above (p. 512). Of the remaining species named in Plagioporus several probably do not belong in the genus. P. serratus Miller, 1940 has a spined cuticula and probably belongs in the family Lepocreadiidae. I agree with Miller (1940)

that P. obducta (Nicoll, 1909) Price, 1934 does not belong in the genus Not only is the genital pore median but there is doubt if a cirrus sac is present. Lebouria truncata Linton, 1940 is also a doubtful Plagioporus species as its cirrus sac was not observed. I consider P. varius (Nicoll, 1910) Price, 1934 a synonym of P. alacer (Looss, 1901) Price, 1934 P. pallensicus (Shipley and Hornell, 1905) Yamaguti, 1952 (?) is incompletely described. “Plagioporus angusticolle (Hausmann, 1896) Dobrovolny, 1939” was reported from Salmo gairdnerii, the rainbow trout, in California by Haderlie (1953). However, Hausmann's 1897 description and figure (Rev. Suiss Zool., vol. 5, pp. 1–42, pl I, fig. 1) shows that the California species is different in several respects, notably in the anterior extent of the vitellaria which reach the oral sucker in P. angusticolle, and in the shape and extent of the cirrus sac which is elongate and reaches even past the acetabulum in P. angusticolle. Haderlie also reports one specimen of “Plagioporus serotinus Stafford, 1904” from Archoplites interruptus in California. However, the shape of the cirrus sac differs from the Canadian species (Miller, 1940, p. 424) and judging from Haderlie's figure the egg size is considerably smaller than the 70 to 90μ of P. serotinus. Plagioporus macrouterinus Haderlie, 1953 is unusual in that the uterus extends backward to overlap the posterior testis. Haderlie decided his specie was “not close to … the genus Allocreadium” but did not say why, presumably because the genital pore is not median. Stafford (1904) named Stenakron vetustum for a trematode listed as “Distomum sp” from Limanda ferruginea by Linton (1901) at Woods Hole, Massachusetts. Stafford reported it from two Canadian fishes but since he gave no description the genus and species must be based on the Woods Hole material, Miller (1941) describes Stafford's material from Hemitripterus americanus. Neither description is entirely complete and it is possible that Miller's specimens (with deeply lobed or even fragmented ovary) are not conspecific with the Woods Hole species. Linton's figure strongly suggests Plagioporus subgenus Caudotestis. It is to be hoped that more detailed knowledge of Stenakron will permit both genera as otherwise Plagioporus will become a synonym of Stenakron (page priority). Another genus related to Plagioporus is Eurycreadium Manter, 1934 which differs only in that both testes are posterior to the caeca and the genital pore is more median. Because of the wide distribution and common occurrence of the genus Plagioporus, a key to species of the subgenus Plagioporus is given here Key To Species Of The Genus Plagioporus, Subgenus Plagioporus 1 (4) Genital pore opposite oral sucker 2 2 (3) Testes lobed P. preporatus (this paper) 3 (2) Testes unlobed P. dactylopagri (this paper) 4 (1) Genital pore posterior to oral sucker 5 5 (6) Ovary lobed 7 6 (5) Ovary unlobed 17 7 (10) Testes lobed 8 8 (9) Sucker ratio 1: 1.8 to 2.36 P. lobatus (Yamaguti, 1934) Yamaguti, 1938

9 (8) Sucker ratio 1: 1.4 to 1.6 P. acanthogobii Yamaguti, 1952 10 (7) Testes unlobed 11 11 (12) Eggs only about 22μ long P. choerodonis (Yamaguti, 1934) Yamaguti, 1938 12 (11) Eggs at least 54μ long, usually more than 70p 13 13 (14) Excretory vesicle long extending anterior to acetabulum P. longivesicula Yamaguti. 1952 14 (13) Excretory vesicle short, not teaching acetabulum 15 15 (16) Genital pore posterioi to pharynx, eggs 90–98μ P. elongata (Goto and Ozaki, 1930) Price 1934 16 (15) Genital pore opposite pharynx; eggs 75–82μ P, ira Yamaguti, 1940 17 (22) Vitellaria interrupted opposite acetabulum 18 18 (21) Testes tandem; vitellaria reaching to pharynx 19 19 (20) Vitellaria interrupted opposite testes P. interruptus (this paper) 20 (21) Vitellaria not interrupted opposite testes P. isaitschikowi (Layman, 1930) Price, 1934 21 (18) Testes oblique; vitellaria not leaching pharynx P. macassarensis Yamaguti, 1952 22 (17) Vitellaria not interrupted opposite acetabulum 23 23 (24) Genital pore opposite pharynx 25 24 (23) Genital pore posterior to pharynx 29 25 (26) Acetabulum less than 2X oral sucker P. calotomi (Yamaguti. 1934) Yamaguti, 1938 26 (25) Acetabulum at least 2X oral sucker 27 27 (28) Acetabulum at midbody; uterus extending to posterior testis P. branchiostegi (Yamaguti, 1937 28 (27) Acetabulum anterior to midbody; uterus not extending to posteriortestis P. japonicus Yamaguti. 1938 29 (32) Vitellaria extending to base of oral sucker 30 30 (31) Cirius sac extending to posterior edge of acetabulum or bevond P. angusticolle (Hausmann. 1896) Dobrovolny, 1939 31 (32) Cirrus sac not extending to posterior edge of acetabulum P. apogonichthydis Yamaguti. 1938 32 (29) Vitellaria not extending to base of oral sucker 33 33 (34) Uterus extending to posterior testis P. macrouterinus Haderlie, 1953 34 (33) Uterus not extending to posterior testis 35 35 (36) Excretory vesicle long, reaching to anterior end of acetabulum P. isagi Yamaguti. 1939 36 (35) Excretory vesicle not reaching to anterior end of acetabulum 37 37 (40) Vitellaria not extending anterior to acetabulum 38 38 (39) Excretory vesicle reaching to ovary P. virens Sinitsin, 1931 39 (38) Excretory vesicle short, reaching only to posterior testis P. lepomis Dobrovolny, 1939 40 (37) Vitellaria extending anterior to acetabulum 41

41 (42) Ovary in midline, directly antenor to testes 43 42 (41) Ovary slightly to right of midline 47 43 (44) Vitellaria not reaching anterior to intestinal bifurcation P. siliculus (Nicoll, 1909) Price, 1934 44 (43) Vitellaria extending anterior to intestinal bifurcation 45 45 (46) Acetabulum much larger than oral sucker, uterus extending to anterior testis P. pacificus Yamaguti. 1952 46 (45) Acetabulum only slightly larger than oral sucker; uterus entirely preovarian 48 47 (50) Testes tandem P. occidentalis Szidat. 1944 48 (49) Excretory vesicle extends only to posterior testis P. serotmus Stafford, 1904 49 (48) Excretory vesicle extends to ovary P. sillagonis Yamaguti, 1938 50 (47) Testes oblique 51 51 (52) Seminal receptacle posterior to ovary; eggs 85–92μ P. alacer (Looss, 1901) Price. 1934 52 (51) Seminal receptacle anterior to ovary; eggs 71–74μ P. idoneus (Nicoll. 1907) Price, 1934 30. Podocotyle caithnessi n.sp. (Figs. 39–40) Host: Leptocephalus conger (Linn.), conger eel; intestine. Locality: Wellington. HOLOTYPE: U.S. Nat. Mus. Helminth. Collection No. 49134. DESCRIPTION (based on 8 specimens): Body more or less cylindrical; 2.314 to 2.856 mm. long by 0.588 to 0.672 mm. in greatest width which is at acetabular level. The acetabulum is protuberant and can be extended a length equal to the forebody. Forebody 0.388 to 0.658 mm. long or varying from about ¼ to ⅛ body length. Hindbody almost equally wide with broadly rounded posterior end. Oral sucker 0.146 to 0.184 mm. in transverse diameter; acetabulum 0.292 to 0.331 mm. in diameter. Sucker ratio 1:1.7 to 2. Prepharynx short; pharynx somewhat wider than long, 0.087 to 0.106 mm. long by 0.114 to 0.125 mm. wide. Oesophagus twice length of pharynx. Genital pore sinistral, about halfway toward left side of body at about mid-oesophageal level. Testes two, ovoid, smooth, tandem or slightly diagonal in posterior half of hindbody, separated by at least a slight space but not by vitellaria. Cirrus sac (Fig. 40) claviform with slender anterior half and broadly rounded posterior end, not extending posterior to acetabulum and usually only to about midacetabular level, length 0.269 to 0.378 mm., width 0.095 mm. Seminal vesicle coiled with one backward loop. Cirrus rather lone but weak. Ovary 3-lobed, about at middle of hindbody. Seminal receptacle dorsal to ovary. Vitelline follicles usually beginning a short distance posterior to acetabulum rarely reaching to acetabulum; unbroken to posterior end of body; dorsal, ventral, and lateral to caeca; meeting medianly only near posterior end of body. Eggs 68 to 80 by 38 to 57μ; uncollapsed eggs 76 to 88 by 50 to 57μ. Excretory vesicle dorsal to testes ending dorsal to ovary.

Discussion: This species will key to P. sygnathi in keys by Dawes (1946) and Park (1937). It differs as follows: (1) the eggs are 68 to 76 by 38 to 57μ as compared with 82 to 102 by 45 to 50μ, (2) the sucker ratio is 1.1.7 to 2 rather than 1.1 to 1 45; (3) width of hindbody is less compared with width at acetabular level. It is also similar to P. atomon (Rud., 1802) Odhner, 1905 agreeing in size, sucker ratio, and egg size. Furthermore, P. atomon is noted for variability. However, the cirrus sac of P. atomon extends posterior to the acetabulum. The vitellaria tend to extend further forward in P. atomon although the least extent is about the same as the greatest extent in my specimens. P. atomon has a wide host and geographical distribution being reported form more than 55 species of fishes and occurring in European waters, American North Atlantic, and in the Pacific from British Columbia and California. On the other hand, Yamaguti does not report it from Japan; nor does it seem to occur at Tortugas, Florida. Nicoll (1910) states it is the commonest parasite of inshore fishes in the Firth of Clyde where it occurs in nearly ¼ of all fishes and m 40% of gadoid fishes. He also notes, (p. 323–324) that “several hundred deep-water fishes” were examined without a single infection and concludes that it is a strictly littoral species. The lack of host specificity of P. atomon suggests that of Derogenes various which, however, unlike P. atomon thrives in deepwater fishes and has a much wider geographical distribution (bipolar as well as deepwater). P. atomon was listed by Nicoll (1915) and by Dawes (1947) as having been reported from Conger conger but not from that host in British waters I have been unable to locate the authority for the record from Conger. It is possible that such material might be P. caithnessi but P. atomon does occur in both European and American species of Anguilla and may well infect Conger. Another closely related species is P. gibbsoniae Johnson, 1949* The original spelling of this name was “qibbsoma” but the genitive case must have been intended. from Gibbsonia elegans in California. The two species agree in sucker ratio, digestive system, extent of cirrus sac, and extent of vitellaria. The chief difference is the presence of lobed testes in P. gibbsoniae which also has vitellaria between the testes, and smaller eggs (62 to 66 by 33 to 44μ). Park (1937) has reviewed the genus Podocotyle 31 Helicometra grandora n.sp. (Figs. 41–42) Hosts: Chelidonichthys kumu it (Lesson and Garnot), gurnard; type host; intestine; Helicolenus percoides (Richardson), sea perch; intestine. Localities. Portobello, Wellington. Holotype: U.S. Nat. Mus. Helminth. Collection No. 49135. Description (based on 45 specimens with measurements on eight): Length 2.478 to 3.738 mm., greatest width 1.162 to 1.460 mm. near middle of body; tapering toward each end but broadly rounded at posterior end. Forebody 0.532 to 1.036 mm. or from ½ to ¼ body length. Oral sucker round, large, 0.377 to 0.478 mm. in diameter, acetabulum slightly wider than long, 0.323 to 0.408 mm. in transverse diameter. Sucker ratio 1:0.807 to 0.920, usually about 0.880. Very

short prepharynx, pharynx appreciably longer than wide, 0.177 to 0.237 mm. long by 0.115 to 0.146 mm. wide; oesophagus muscular, usually not longer than pharyrx, almost always shorter than pharynx. The specimen from Helicolenus had a greatly extended forebody and its oesophagus was slightly more than twice the lergth of the pharynx. Oesophagus length doubtless varies greatly with contraction of the forebody. Intestinal bifurcation about midway between suckers; caeca reaching to near posterior end of body. Testes much lobed, tandem, intercaecal, close together; anterior testis about at middle of hindbody. Posttesticular space 0.546 to 0.868 mm. or between ¼ and 1/5; body length. Genital pores median at level of posterior edge of pharynx; female pore close in front of male pore Cirrus sac (Fig. 42) overlapping acetabulum, usually not reaching to midacetabulum, rarely somewhat past mid-acetabulum; size 0.362 to 0.501 mm. long by 0.123 to 0.184 mm. wide. Seminal vesicle tubular extending forward to near anterior end of the cirrus sac then backward in short coils to join the muscular cirrus in posterior fourth of the sac; the cirrus bends forward and extends almost straight to the male pore (Fig. 42). Ovary deeply 3-lobed, median, immediately pretesticular. Seminal receptacle originating anterior to ovary extends posterior to ovary on right side. Vitellaria begin a little anterior to acetabulum and extend to near posterior end of body. They may begin as far forward as the level of the intestinal bifurcation or as far back as anterior edge of acetabulum. Uterus a narrow spiral between ovary and acetabulum. Filamented eggs 68 to 84 by 26 to 34μ, not including the long filamen. Excretory vesicle extending to the transverse yolk duct just anterior to the ovary. Discussion: The following species have been named in the genus Helicometra: H. bassensis Woolcock. 1935; H. epinepheli Yamaguti, 1934; H. execta Linton. 1910; H. fasciata (Rud, 1819) Odhner, 1902; H. hypodytis Yamaguti, 1934: H. pulchella (Rud., 1819) Odhner, 1902; H. neosebastodis Crowcroft, 1947, H. tenuifolia Woolcoek, 1935; H. torta Linton, 1910; H. sinuata (Rud, 1819) Odhner 1902 H. gurnadus Thapar and Dayal, 1934, reported from a gurnard. Trigla gurnardus, unfortunately appears to be at present a nomen nudem since no description of it was given. H. hypodytis and H. epinepheli are probably synonyms of H. fasciata. H. grandora differs from all these species except H. neosebastodis and H. tenuifolio in that the oral sucker is larger than the acetabulum. It is very similar to H. fisciata except for tins very evident difference in the sucker ratio and a more elongated pharynx. It differs from both H. neosebastodis and H. tenuifolia in extent it of the vitellaria at least to anterior border of the acetabulum, and in much more lobed testes and ovary. It might be noted that H. tenuifolia was reported from one of the same hosts, Helicolenus percoides, in Port Philip Bay. Australia. 32. Coitocaecum tylogonium n. sp. (Fig. 43) Host: Centriscops humerosus (Richardson), bellows fish; intestine. Locality: Portobello. Holotype:. U. S. Nat. Mus. Helmunth. Collection No. 49136.

Description (based on one specimen): Body elongate with tapering forebody: broadly rounded posterior end. Length 3.204 mm.; width 0.868 mm., widest near middle of hindbody. Forebody (extended) 0.980 mm.; posttesticular space 0.714 mm. Oral sucker slightly longer than wide, 0.254 mm. wide; acetabulum slightly wider than long, 0.455 mm. wide. Sucker ratio 1.18. Prepharynx short and wide; pharynx 0.129 mm. long by 0.137 mm. wide; oesophagus about same length as pharynx; bifurcation a little nearer to oral sucker than to acetabulum; caeca diverging very gradually, uniting 0.162 mm. from posterior end of body, nearer posterior end than to testes. Genital pore median, slightly posterior to intestinal bifurcation. Testes tandem. Slightly lobed, close together, anterior testis about in middle of hindbody. Cirrus sac muscular, ovoid, slightly wider anteriorly, intercaecal, 0.152 mm. long by 0.095 mm. wide; containing prostatic cells, a straight cirrus, a small ovoid pars prostatica, and a short tubular extension of the seminal vesicle. External seminal vesicle club-shaped, extending dorsally to the left caecum to the left anterior edge of acetabulum. Ovary deeply 4-lobed, lateral lobes with short stalks; median, immediately pretesticular Mehlis' gland preovarian, well developed. Transverse yolk duct swollen but partly empty Metraterm not noted Vitellaria from level of oesophagus to posterior end of body; interrupted opposite acetabulum, chiefly ventral and lateral to caeca but continuous dorsally across the oesophagus; continuous ventrally posterior to testes and posterior to caecal union. Eggs 53 to 57 by 30 to 32μ. The excretory vesicle could be traced only to the posterior testis. Its anterior ending was not observed. The name tylogonium is from tylo, knob and gon, sexual, and refers to the knobbed or lobed ovary. Discussion: This species of Coitocaecum is unique in its lobed ovary and unusual in the interruption of the vitellaria opposite the acetabulum. It keys to C. ovatum Pigulesky, 1931 in Crowcroft's (1945, pp. 65–66) key but differs in being more than twice as long, in having much smaller eggs, a prepharynx, long oesophagus, as well as deeply lobed ovary. It differs from C. anaspidis Hickman, 1934, in lobed and tandem gonads, larger pharynx, interrupted vitellaria, much smaller eggs, and more posterior genital pore. It differs from C. xesuri Yamaguti, 1940 in more posterior genital pore, lobed ovary, interrupted vitellaria, and longer oesophagus but does have a similar egg size which is relatively small for the genus. 33. Coitocaecum anaspidis Hickman, 1934 Host. Anguilla dieffenbachis Gray, 1842; eel. Locality: Wellington. Specimen Deposited: U. S. Nat. Mus. Helminth. Collection No 49164. This species was reported by Macfarlane (1939) from young eels, young Salmo fario, Gobiomorphus gobioides, Galaxias brevipennis, and Galaxias attenuatus. Hickman found it as progenetic specimens in the freshwater amphipod, Anaspides tasmaniae in Tasmania. Macfarlane (1939) discovered its life cycle. Cotylocercous cercariae develop in sporocysts in the snails Potamopyrgus antipodum and P. badia. In New Zealand metacercariae occur in Paracalliope, fluviatilis, a freshwater amphipod, in which progenetic specimens were fairly common.

34. Decemtestis pseudolabri n.sp. (Figs. 44–47) Host: Pseudolabrus celidotus (Forster), spotty; intestine. Locality: Wellington. Holotype: U.S. Nat. Mus. Helminth. Collection No. 49137. Description (based on six specimens with measurements on four. These specimens were dead when collected and slightly macerated. They were not flattened in killing): Length 0.539 to 0.616 mm., width 0.200 to 0.246 mm., widest at acetabulur level near midbody. Body rather plump; cuticula smooth. Sucker widths as observed in one specimen: oral sucker 0.110 mm.; acetabulum 0.146 mm; sucker ratio 1:1 3. Sucker lengths: oral sucker 0.093 to 0.112 mm.; acetabulum 0.138 to 0.153 mm.; ratio of lengths 1:1.23 to 1.5. Acetabulum with central muscular portion which was everted in all specimens. It is probably similar to the “double acetabulum” of Decemtestis biacetabulata Srivastava, 1936. Forebody 0.177 to 0.231 mm. In mature specimens the acetabulum is just anterior to midbody while in mature specimens the forebody is longer than the very short hindbody. Prepharynx short; pharynx 37 to 42μ long by 41 to 44μ wide; oesophagus present. No specimens showed the entire digestive tract so the exact lengths of the oesophagus and caeca were not determined. The caeca probably do not reach to the posterior end of the body; in one case a caecum ended opposite the next to last testis; in another not quite so far. Genital pore to left of midline opposite posterior part of pharynx. Testes ten; ventral; crowded in posterior half of hindbody; extending to posterior end of body; usually five on one side, four along the other with one somewhat more median sometimes partly overlapping. Cirrus sac clavate, extending diagonally backward to a point from the middle to posterior edge of acetabulum or slightly beyond; containing a looped seminal vesicle, prostatic cells and a muscular cirrus about one third length of cirrus sac. In a 0.562 mm. specimen the cirrus sac was 0.138 by 0.037 mm. Ovary very indistinct, pretesticular, without distinct membrane in these specimens, probably more or less three-lobed. Seminal receptacle dorsal and posterior to ovary; Mehlis' gland dorsal to ovary. Uterus short, pretesticular, mostly dorsal to ovary; eggs without filaments, 35 to 42 by 20 to 27μ. Metraterm thin-walled, approximately same length as cirrus sac. Vitelline follicles relatively large, scattered, extending dorsal to other organs almost throughout the body from posterior edge of oral sucker to near posterior end; not extending posterior to testes. Some follicles are dorsal to pharynx, acetabulum, and testes, but a region opposite Mehlis' gland is relatively free of them. Excretory pore terminal; vesicle not traced. Discussion: In spite of the rather poor condition and very small size of the specimens, it is clear that they belong in the genus Decemtestis Yamaguti, 1934. Fourteen species have been named in this genus, 11 from the North Pacific. 3 from India. A few of the North Pacific species should probably be reduced to synonymy. D. pseudolabri is much smaller than any of the other species and has a much shorter hindbody. The doubled character of the acetabulum, which might prove to be a valid generic character, occurs also in D. biacetabulata Srivastava, 1936 from Scomber micropeditorus in the Bay of Bengal. D. pseudolabri differs from this species in sucker ratio; in body proportions as well as size; in smaller

eggs (35 to 44 by 20 to 27 p, as compared with 52 to 56 by 30 to 39μ) which are, however, large compared with body size; and in distribution of vitellaria which do not extend posterior to the testes. The size and general appearance of D. pseudolabri suggests Helicometrina parva Manter, 1933, but it differs in non-filamented eggs and number of testes. Key To Described Species Of Decemtestis 1 (4) “Double” acetabulum (one within another) 2 2 (3) Vitellaria extending posterior to testes D. biacetabulata Srivastava. 1936 3 (2) Vitellaria not extending posterior to testes D. pseudolabri 4 (1) Acetabulum single, i.e. typical 5 5 (8) Vitellaria broken opposite acetabulum 6 6 (7) Cirrus sac not extending posterior to acetabulum D. kobayashii Park, 1939 7 (6) Cirrus sac extending posterior to acetabulum D. callionymi Yamaguti, 1934 8 (5) Vitellaria continuous 9 9 (10) Cirrus sac not leaching acetabulum D. brevioirrus Srivastava, 1936 10 (9) Cirrus sac reaching acetabulum or beyond 11 11 (18) Ovary only slightly indented 12 12 (15) Testes in longitudinal rows on each side 13 13 (14) Acetabulum almost 2 × oral sucker D. megacotyle Yamaguti, 1938 14 (13) Acetabulum only slightly larger than oral sucker D. goniistii Yamaguti, 1938 15 (12) At least one testis displaced from a longitudinal low 16 16 (17) Eggs 108 to 117μ long D. spaii Yamaguti. 1938 17 (16) Eggs 54 to 66μ long D. bera Yamaguti, 1938 18 (11) Ovary deeply lobed 19 19 (20) Cirrus sac not extending posterior to acetabulum D. mehrai Srivastava, 1936 20 (19) Cirrus sac extending posterior to acetabulum 21 21 (22) Vitellaria not leaching genital pore D. sillagonis Yamaguti. 1934 (type species) 22 (21) Vitellaria reaching genital pore 23 23 (26) Terminal portion of metratelm with muscular bulb 24 24 (25) Testes often indented D. neopercis Yamaguti, 1938 25 (24) Testes not indented D. pagrosomi Yamaguti, 1938 26 (23) Terminal portion of metraterm without muscular bulb D. azumae (Layman. 1930) Yamaguti, 1934 D. ditrematis Yamaguti. 1934 It is realised that some rather weak characters are used in the above key; for example, testes in a longitudinal row or not, and testes indented or not. It seems probable that a few of these species cannot be well justified. The fact remains that the genus Decemtestis is a fairly large one and so far as is known does not occur in the Atlantic.

35. Brevicreadium congeri n.gen., n.sp. (Figs. 48–49) Host: Leptocephalus conger (Linnaeus), conger eel; intestine. Locality: Wellington. Holotype: U.S. Nat. Mus. Helminth. Collection No. 49138. Description (based on 15 specimens, with measurements on 8): Body smooth, plump, almost as thick as wide; forebody tapering; hindbody broadly rounded. Length 1.050 to 1·442 mm; greatest width just posterior to midbody, 0·570 to 0.770 mm. Forebody 0.392 to 0.570 mm.; hindbody 0·269 to 0·392 mm.; acetabulum somewhat nearer posterior than anterior end. Oral sucker 0.169 to 0.208 mm. wide; acetabulum very large, wider than long, 0.408 to 0.562 mm. wide; suckser ratio 1: 2.3 to 2.7. Acetabular aperture a transverse slit bounded by a distinct anterior and posterior lip with curved transverse muscles (Fig. 48); remainder of acetabulum only weakly muscular. Short prepharynx; pharynx 0.057 to 0.084 mm. long by 0.060 to 0.080 mm wide; oesophagus present varying from about same length as pharynx to more than twice pharynx length; caeca divergent, short, sac-like, ending near anterior edge of acetabulum. Genital pore lateral, on left side, from opposite posterior half of pharynx to a level nearly opposite intestinal bifurcation. Testes ovoid, smooth, symmetrical or subsymmetrical, close together, in middle portion of hindbody. Cirrus sac long, extending almost horizontally but somewhat diagonally from genital pore along most of the anterior border of acetabulum; containing an ovoid seminal vesicle, a prostatic duct surrounded by prostatic cells, and an ejaculatory duel with smaller cells. Cirrus short, fleshy, protrusible (Fig. 49). Ovary ovoid, smooth, just anterior to right testis which it may partly overlap, partly or wholly dorsal to acetabulum. Seminal receptacle sac-like, ventral to ovary. Vitelline follicles relatively few, forming a more or less continuous band ventrally immediately posterior to acetabulum; follicles rounded, close together, exact number difficult to determine but between 20 to 24; more than half the follicles are in the left half of the body seemingly crowded to the left by ovary and uterus. Uterus sending a few coils ventral to testes to near posterior edge of testes or slightly beyond; several short longitudinal coils dorsal to acetabulum. Metraterm thick-walled, with radial and some circular muscles, between genital pore and left caecum, a little less than half length of cirrus sac, containing a basal swelling with sperm cells (Fig. 49). Eggs thin-shelled, rather elongate, tapering slightly more toward one end than the other; 34 to 39 by 15 to 22μ long; uncollapsed, young eggs near ovary are 35 to 39 by 20 to 22μ. Excretory pore dorsal, subterminal; excretory vesicle I-shaped, short, ending dorsal to right testis. The name Brevicreadium is from brevi, short; and creadium, indicating relationship to the Allocreadiidae. Discussions: This small trematode has a fellodistomid appearance but the I-shaped excretory vesicle; the thin-shelled eggs; the undivided seminal vesicle and character of the pars prostatica preclude it from the Fellodistomatidae. Yet it does have some resemblance to Pycnadenoides Yamaguti, 1938 and in particular to P. calami Manter, 1947, a species which has some allocreadid characters (Manter. 1947, pp. 318–319). The fellodistomid genus Yamagutia Srivastava,

1939 has short caeca, lateral genital pore, and short hindbody, but its Y-shaped excretory vesicle seems to make it very different. Among the Opecoelidae, the nearest genus is probably Diplobulbus Yamaguti, 1934 which has similar gonads, cirrus sac, uterus, a lateral genital pore, and lip-like lobes on the acetabulum. Diplobulbus has much more extensive vitellaria filling much of the forebody; longer caeca extending to the posterior edge of the acetabulum; it lacks a muscular metraterm; and the acetabular lips seem to have longitudinal rather than transverse muscles. The genus Labrifer Yamaguti, 1936 has acetabular lips similar to those of Brevicreadium but differs greatly in body form, extent of uterus and vitellaria, in its external seminal vesicle and other characters. Generic Diagnosis Of Brevicreadium: Body smooth, plump, with short rounded hindbody. Acetabulum large with prominent anterior and posterior lips with transverse muscles; caeca very short, not reaching middle of acetabulum. Genital pore lateral, to the left. Testes ovoid, symmetrical or subsymmetrical; cirrus sac long, preacetabular, almost horizontal, with ovoid seminal vesicle. Ovary ovoid, anterior to right testis, overlapping acetabulum; seminal receptacle present; uterus extending to posterior edge of testes or slightly beyond, muscular metraterm present; vitelline follicles few, immediately postacetabular, not extending posterior to testes. Excretory vesicle I-shaped, ending dorsal to testes. Type species: B. congeri. Family Fellodistomatidae 36. Benthotrema richardsoni n.sp. (Figs. 50–52) Host: Pelotritus flavilatus Waite, lemon sole; intestine. Locality: Wellington. Holotype: U.S. Nat. Mus. Helminth. Collection No. 49139. Description (based on five specimens): Body smooth, 1·400 to 1.680 mm. long by 0.485 to 0·601 mm. wide; widest in anterior half; broadly rounded at each end. Oral sucker subterminal, large, longer than wide; 0.277 to 0.339 mm. in transverse diameter; with longitudinal aperture. Acetabulum near midbody, slightly wider than long, 0.154 to 0.185 mm. in transverse diameter. Sucker ratio 1: 0.55 to 0.57 as based on transverse diameters; entire oral sucker considerably more than twice the size of acetabulum. Forebody 0·624 to 0.823 mm. or up to slightly over ½ total body length. Prepharynx not visible; pharynx 0.076 to 0.095 mm long by 0.072 to 0.091 mm. wide; oesophagus lacking; caeca divergent, extending obliquely backward, ending usually at level of anterior edge of acetabulum at most at midacetabular level, anterior to ovary and testes. Genital pore a little to the left shortly anterior to acetabulum. Testes spherical, slightly smaller than acetabulum, symmetrical, widely separated, near acetabulum which they partly perhaps mostly, overlap laterally; not extending anterior to acetabulum. Cirrus sac (Fig. 51) extending diagonally or almost horizontally to the right from the pore, preacetabular; containing a tubular, looped seminal vesicle with one anterior and one posterior coil, a large ovoid prostatic vesicle, and prostatic cells. A muscular cirrus is lacking being replaced by a very short, thin-walled tube leading from the prostatic vesicle to the muscular genital atrium. Genital atrium with very thick wall, surrounded by conspicuous gland cells (Fig. 51) and with a few radiating muscles.

Fig. 45— Anterior end of D. pseudolabri. Ventral view. Fig. 46—Posterior end of D. pseudolabri. Dorsal view to show testes. Fig. 47—Egg of D. pseudolabri. Fig. 48—Brevicreadium Congeri from Leptocephalus conger. Ventral view. Fig. 49—Terminal genital organs of B. congeri. Fig. 50—Benthotrema richardsoni from Pelotritus flavilatus. Ventral view. Fig. 51—cirrus sac and adjacent organs of B. richardsoni. Ventral view. Fig. 52—Eggs of B. richardsoni. Fig. 53—Tergestia agnostomi from Agnostomus forsteri. Ventral view. Fig. 54— Portion of forebody of T. agnostomi showing two cuticular flanges. Ventral view. Fig. 55—Cirrus sac of T. agnostomi. Ventral view.

Ovary spheroid, unlobed, to the right at level of acetabulum, immediately anterior to right testis. Seminal receptacle lacking. Mehlis′ gland between ovary and cirrus sac; uterus extending to near posterior end of body. Metraterm lacking. The muscular genital atrium seems to function as both cirrus and metraterm. Eggs (Fig. 52) thick-shelled, almost as wide as long, 25 to 30 by 19 to 24. Vitelline follicles small, rather irregular in shape, preacetabular, forming a wide band across the forebody dorsal to the excretory crura and digestive system and filling most of the area between the suckers. The follicles may overlap the oral sucker laterally. Excretory pore terminal; gland cells near the pore; excretory vesicle Y-shaped, inflated; median stem forking just posterior to acetabulum; crura overlapping oral sucker laterally. The trivial name is in honour of Professor L. R. Richardson, professor of zoology at Victoria University College, who cooperated in many ways during the collection and study of these New Zealand trematodes. Discussion: The genus Benthotrema Manter, 1934 was named for a species, B. plenum, from a “lizard fish “from a depth of 582 fathoms at Tortugas, Florida. Since 1934 one other species has been named, B. hoplognathi Yamaguti, 1938 from Hoplognathus fasciatus in Japan. The genus is characterized by short caeca; preacetabular vitellaria; unlobed ovary to the right at acetabular level; and weakly developed cirrus. Yamaguti reported a seminal receptacle present in B. hoplognathi but such an organ is very rare, if not doubtful, in the family Fellodistomatidae, and a further check should be made regarding this point. The genus Pseudosteringophorus Yamaguti, 1940 is closely related but has a peculiar atrial sac with hair-like processes. The genus Bacciger Nicoll, 1914 has a median ovary and median genital pore. B. richardsoni differs from B. plenum in non-spiny egg shells and in having the oral sucker much larger than the acetabulum. It differs from B. hoplognathi also in its much larger oral sucker, in more tubular seminal vesicle, in shorter prostatic vesicle, and in lacking a muscular metraterm. 37. Tergestia agnostomi n.sp. (Figs. 53–55) Host: Agnostomus forsteri Cuv. and Val, herring or yellow-eyed mullet, intestine; Locality: Wellington. Holotype: U.S. Nat. Mus. Helminth. Collection No. 49140. Description (based on 5 specimens none of which were mature enough to have eggs in the uterus): Length 1.218 to 1.554 mm; greatest width 0.239 to 0.292 mm. near acetabular level; entire body almost equally wide Forebody varying with contraction, 0.408 to 0.639 mm., usually ⅓ or more of total body length. Oral sucker 0.169 to 0·232 mm. wide; acetabulum 0.131 to 0.161 mm. wide, smaller than oral sucker. Sucker ratio 1:0.70 to 0.77 Semicircle of thirteen lance-shaped lobes dorsal and lateral to oral sucker. Six pairs of “folds” or flanges on sides of forebody. These are actually definite, cuticular structures in the form of curved cylinders with a sharp, outer, median ridge Dorsally they extend somewhat more medianly than they do ventrally but they do not meet

(Fig.54). Pharynx very large, 0.176 to 0·192 mm. long by 0.092 to 0.108 mm. wide; longer than diameter of acetabulum. Oesophagus very long, forking just posterior to acetabulum; caeca end blindly shortly posterior to testes. Testes ovoid, diagonal, intercaecal, in posterior half of hindbody (in these immature specimens). Cirrus sac curved around left side of acetabulum; its narrowed posterior half containing a straight seminal vesicle; its wider anterior half a pars prostatica and a wide cirrus with folded walls. Ovary elongate oval, preteslicular, to the right. Traces of vitellaria between just posterior to acetabulum and anterior testis. Discussion: Although the specimens were not fully grown, it is clear that they represent a new species on the basis of the sucker ratio. The following species of Tergestia are known T. laticollis (Rud., 1819) Odhner, 1911; T. pectinata (Linton, 1905) Manter, 1940; T. acuta Manter, 1947; T. acanthocephala (Stossich, 1887) Odhner, 1911; and T. acanthogobii Yamaguti, 1938. In none of the” is the acetabulum smaller than the oral sucker or smaller than the length of the pharynx. In most species the acetabulum is much larger than the oral sucker. The most similar species is T. laticollis in which the acetabulum is only slightly larger than the oral sucker and about the same diameter as the length of the pharynx. T. laticollis is a widely distributed species. It s possible that Agnostomus is not an appropriate host for the adult trematode. Key To Species Of Tergestia 1 (2) Acetabulum smaller than oral sucker T. agnostomi (this paper) 2 (1) Acetabulum larger than oral sucker 3 3 (4) Acetabulum only slightly larger than oral sucker T. laticollis (Rud., 1819) Odhner, 1911 4 (3) Acetabulum at least 2 × oral sucker 5 5 (8) Vitellaria confluent anterior to ovary 6 6 (7) Posterior end pointed; eggs 17–19 by 9–10μ T. acuta Manter, 1947 7 (6) Posterior end not pointed; eggs 21–27 by 14–18μ T. acanthogobii Yamaguti, 1938 8 (5) Vitellaria not confluent anterior to ovary 9 9 (10) Pharynx length less than 2 × width T. acanthocephala (Stossich, 1887) 10 (9) Pharynx length more than 2 × width T. pectinata (Linton, 1905) Manter, 1940 38. Steringotrema rotundum n.sp. (Figs. 56–58) Host: Parapercis colias (Forster), blue cod; gall bladder and stomach. Locality: Portobello. Holotype: U. S. Nat. Mus. Helminth. Collection No. 49141. Description (based on two specimens. A second collection of six somewhat smaller sized specimens were accidentally dried in vial. Lacto-phenol solution partially restored the collapsed state of the latter but measurements would probaly be somewhat unnatural). Body plump, pyriform; length 1·554 to 1.652 mm.; greatest width just posterior to acetabulum, 1.078 to 1·162 mm. Forebody 0·539 to 0·662 mm., tapered; hindbody broadly rounded, thick, distended with eggs. Oral sucker 0.192 to 0·207 mm.; acetabulum wider than long, 0.539 to 0·639 mm. wide, with transverse aperture; sucker ratio 1:2.8 to 3. Prepharynx

short or lacking; pharynx 0·099 to 0·118 mm. long by 0·102 mm. wide; oesophagus present but indistinct; caeca not completely seen but apparently ending at about midacetabular level at anterior edge of vitellaria. Genital pore well to the left a short distance preacetabular. Testes two, more or less symmetrical, far apart, shortly posterior to acetabulum, ovoid, slightly longer than wide. Cirrus sac (Fig. 58) very large, ovoid, diagonal, filling most of forebody, 0.462 to 0·539 mm. long by 0·193 to 0·231 mm, wide, overlapping the right anterior portion of acetabulum. Seminal vesicle bipartite, with basal portion bent once. Pars prostatica large, with one curve, wider anteriorly, with long filament-like processes; prostatic cells numerous. Cirrus represented only by a short wide space leading by a narrow duct to a spacious genital atrium with slightly convoluted wall and often containing some eggs. Ovary indistinct or invisible, obscured by eggs in most specimens; ovoid, longer than wide, just median to right testis and just to right of midline. Vitelline follicles close together forming two lateral groups from level of middle of acetabulum to middle of hindbody or about to level of testes; follicles extend medianly near ventral surface posterior to acetabulum but do not meet; vitelline ducts meeting at left side of ovary. Uterus filling hindbody almost completely, covering both ovary and testes. Eggs yellow, thick-shelled, 34 to 41 by 22 to 25μ. Excretory pore not observed. Excretory crura reach to pharynx level and almost to posterior end of body so that the vesicle must be V-shaped or almost so, as is true for the genus. The name rotundum is for the swollen hindbody. Discussion: The following species of Steringotrema are known: S. cluthense (Nicoll, 1909) Odhner, 1911, type species; S. pagelli (van Beneden, 1870) Odhner, 1911; S. divergens (Rudolphi, 1809) Odhner, 1911; S. nakazawai Kobayashi, 1921; S. corpulentum (Linton, 1905) Manter, 1931; and S. ovatum Price, 1934. The last two of these are doubtful members of the genus, the genital pore being median. S. rotundum differs from the other species in distribution of the vitellaria from middle of acetabulum to middle of hindbody; and in its very large cirrus sac. In S. cluthense the vitellaria extend anterior to the acetabulum, and in S. pagelli and S. nakazawai to the anterior edge of the acetabulum. Perhaps S. nakazawai, from Sparus latus in Japan, is the most closely related species, but its acetabulum is even larger and the caeca longer. S. pagelli is most similar in the development of the uterus and in general appearance but has eggs 57 to 63 by 33 to 37μ in size. 39. Proctoeces subtenue (Linton, 1907) Hanson, 1950 Synonym: P. erythraeus Odhner. 1911. Host: Latridopsis ciliaris (Forster), moki; posterior part of intestine. Locality: Wellington. Specimen Deposited: U.S. Nat. Mus. Helminth. Collection No. 49166. Discussion: Five specimens, two immature, agree with specimens collected at Tortugas, Florida and Bermuda (Manter, 1947; Hanson, 1950). The sucker ratio is 1:1.5 to 1.73; eggs measure 46 to 55 by 20 to 23μ; and the vitellaria do not extend posterior to the testes. This species is now known from the Red Sea, Tortugas, Bermuda, and New Zealand. Tortugas and Bermuda hosts were species of Calamus. Other species in

Fig. 56-Steringotrema rotundum from Parapercis colias. Ventral view. Fig. 57—S. rotundum. Young specimens to show ovary and testes. Ventral view. Fig. 58—Cirrus sac of S. rotundum Ventral view. Fig. 59—Deretrema minutum from Galaxias attenuatus. Dorsal view. Fig. 60—Cirrus sac of D. minutum. Dorsal view. Fig. 61—Posterior end of body of D. minutum showing excretory vesicles. Fig. 62—Bivesiculoides otagoensis from Plagiogenion rubiginosus. Ventral view. Fig. 63—Egg of B. otagoensis. Fig. 64—Lecithochirium genypteri from Genypterus blacodes. Ventral view. Fig. 65—Anterior end of L. genypteri showing lobes in oral sucker. Ventral view. Fig. 66—Terminal genital organs of L. genypteri. Lateral view.

the genus are P. mauvlatus (Looss, 1901) Odhner, 1911 from Labrus merula and Crenilabrus pavo in the Mediterranean and from species of Duymaeria, Epinephelus, Pagrosomus, and Sparus in Japan; and P. magnorus Manter, 1940 from Caulolatilus anomalus (?) from the Mexican Pacific. Family Steganodermatidae 40. Deretrema minutum n.sp. (Figs. 59–61) Host: Galaxias attenuatus (Jenyns), minnow; intestine. Locality: Wellington. Holotype: U.S. Nat. Mus. Helminth. Collection No. 49142. Description (based on 12 specimens, with measurements on six): Body ovoid and rather plump before flattening, 0.501 to 0.862 by 0.185 to 0.308 mm., widest near midbody, rounded at each end. Spined anteriorly, spines disappearing near midbody. Suckers round; oral sucker 0.087 to 0.124 mm. wide; acetabulum 0.076 to 0.119 mm.; sucker ratio 1:0.93 to 1. Forebody 0.171 to 0.239 mm. or about ⅓ to ¼ body length. Prepharynx very short; pharynx 0.034 to 0.046 mm. long by 0.036 to 0.054 mm. wide, oesophagus longer than pharynx (up to 2½ times), bifurcation near or slightly anterior to acetabulum; caeca short, wide divergent, sac-like, reaching from near midacetabulum level to posterior edge of acetabulum or very slightly beyond, never reaching beyond testes. Genital pore on left side of body opposite posterior half of oral sucker or, more often, at pharynx level. Testes two, lateral, symmetrical, tending to be somewhat longer than wide, at least partly posterior to acetabulum but overlapping it laterally sometimes almost to its anterior edge. Cirrus sac (Fig. 60) elongate, relatively large, 0.170 to 0.246 mm. long by 0.042 to 0.051 mm. wide, extending diagonally between genital pore and acetabulum. It reaches more than halfway across the body and may or may not overlap the acetabulum up to more than half diameter of acetabulum. It contains an elongate, undivided seminal vesicle in its basal half, a short prostatic vesicle surrounded by large prostatic cells and a fairly long, muscular, unspined cirrus. Cirrus protrusible without eversion. Ovary large, ovoid, very thin-walled, often indistinct, median, between the testes, immediately postacetabular, usually overlapping acetabulum dorsally. anterior end usually somewhat pointed. Seminal receptacle postovarian, flask-shaped or spherical, ventral to yolk reservoir. Vitelline follicles large, in two lateral groups between oral sucker and testes, usually five on each side, rarely six or seven on one side or the other. Uterus filling body posterior to testes; metraterm a narrow tube entering the genital pore from the anterior side, curving across the cirrus sac dorsally, unspined. Eggs golden yellow, fairly thick-shelled, 34 to 41 by 19 to 22μ. Excretory vesicle (Fig. 61) a straight tube concealed by eggs in most specimens. In a 0.501 by 0.185 mm. specimen it extended 0.131 mm. from the posterior end, ending a short distance posterior to the ovary. Discussion: The genus Deretrema was named by Linton (1910) with D. fusillum Linton, 1910 as type species. Eight other species have been named all of which are from the gall bladder of marine fishes although some specimens might

be found in the intestine. The excretory vesicle is I-shaped but in most species lateral tubes are often swollen and could be mistaken for the crura of a Y. The caeca do not extend posterior to the testes except slightly so in D. plotosi Yamaguti, 1940. The genital pore is lateral, the cirrus and metraterm unspined. The genus Brachyenteron Manter, 1934 from the intestine of Peristedion platycephalum at Tortugas, Florida, is a closely related genus. Its chief difference vas stated to be the short caeca ending anterior to the acetabulum. Other characters are a conspicuous sphincter around the metraterm and a bipartite or bent seminal vesicle. These two latter characters are weakly developed in B. dödesrleiniae Yamaguti, 1938. It may be that caecal length will prove unsuitable as a generic character. In B. parexocoeti Manter, 1947 the caeca reach to mid-acetabular level as in D. minutum and the metraterm sphincter was not seen. That species was based on a single specimen and more should be collected and studied to determine its true status. A point of some interest is that two of the four species of Brachyenteron are from bottom, rather than deepwater fishes while the other two are from fishes living close to the surface (Parexocoetus and Fistularia), one of each type occurring at Tortugas and in Japan. A somewhat similar distribution was noted for species of Steganoderma by Manter (1947. p. 312) Another genus closely related to Deretrema is Pseudochetosoma Dollfus, 1952 from tie gall bladder and intestine of freshwater fishes (Salmo macrostigma, Labeobarbus paytoni, Barbus callensis) in Morocco. In fact, there is doubt if the differences listed by Dollfus (1952, p. 382) are of generic value. Thus, some freshwater relatives of Deretrema occur in North Africa. However, Pseudochetosoma salmonicola (Dollfus, 1951) Dollfus, 1952 is not a species closely related to D. minutum. One other related genus, Steganoderma Stafford, 1904 (synonyms: Lecithostaphyhlus Odhner, 1911, Nordosttrema Issaitschikow, 1928; Proctophantastes Odhnen, 1911) might be mentioned. It differs chiefly in that the vitellaria are postacetabular. The caeca extend well posterior to the testes in most but not all species. If Steganoderma is to be separated from Deretrema on the distribution of the vitellaria, S. macrophallus Szidat and Hani, 1951 is somewhat intermediate with the vitelline follicles at acetabular level However, none extend past the acetabulum and that species is more like Deretrema in that respect. Its caeca are shorter than other species of Deretrema and in that respect, as in the case of D. minutum, it resembles Brachyenteron. The best criteria for separation of these genera are not yet clear. Dollfus (1952) in a recent review of the Zoogonidae proposes that the above genera constituting the subfamily Steganodermininae be raised to the rank of a family, Steganodermatidae, and that the Zoogonidae characterized by compact, non-foil cular vitellaria be the only subfamily of the Zoogonidae. This view is accepted here. The Zoogonidae so limited appear to be closely related to the Monorchidae. Previously named species of Deretrema are D. fusillum Linton, 1910; D. cholaeum MacFarlane, 1936; D. fellis (Yamaguti, 1934) Yamaguti. 1940, D plotosi Yamaguti, 1940; D. sebastodis (Yamaguti, 1938) Yamaguti, 1940; D. pooli Annereaux. 1947; D. pacificum Yamaguti, 1942. D. minutum Yamaguti. 1942 D. nahaenes differs from all of these species in its smaller size, in smaller number of

vitelline follicles, and in much shorter caeca. Its cirrus sac is relatively large. Its caeca are almost as short as in Brachyenteron but it lacks a metraterm sphincter and a divided seminal vesicle, and has a more anterior genital pore. The trematode parasites of Galaxidae in South America and in Australia are as yet unknown. In view of the interest incident to the geographical distribution of these fishes, the affinities of Deretrema minutum might be noted. The genus Deretrema has a wide distribution in marine fishes. Of the 13 species other than D. minutum all are marine; three are from Tortugas, Florida; two are from the American Pacific; eight are from Japan. Thus, eleven of the fourteen species are from the Pacific, more than half of them from Japan. Most species of Deretrema are reported from a single species of host but D. fusillum occurred in three different hosts, each of a different family, and D. pacificum in two. As a genus Deretrema occurs in an unusually wide variety of marine fishes including eleven different families. These conditions might seem to indicate that Galaxias acquired D. minimum from marine sources. But Szidat and Hani (1951, pp. 345–347) have recently described Steganoderma messjatzevi from an Antherinid fish, Bastlichthys microlepidotus, from rivers of Argentina. As noted above, S. messjatzevi probably should be placed in the genus Deretrema. It is remarkably similar to D. minutum in size, sucker ratio, digestive system, egg size, and large cirrus sac, differing only in slightly more posterior vitellaria and in less lateral genital pore. I consider its correct name to be Deretrema messjatzevi (Szidat and Hani, 1951) n. comb. Very few genera of trematodes occur in both freshwater and marine fishes Deretrema is widely distributed in marine fishes particularly of the Pacific, and two species are now known from brackish or freshwater minnow-like fishes, one in Argentina, one in New Zealand. Another trematode known from Galaxias in New Zealand (Macfarlane, 1939) is Coitocaecum anaspidis Hickman, 1934. It was first known from progenetic specimens occurring in a crustacean, Anaspides tasmaniae, in Tasmania. Family Heterophyidae 41. Telogaster opisthorchis Macfarlane, 1945 Host: Anguilla dieffenbachii Gray, 1842. eel. Locality: Wellington. Specimen Deposited: U.S Nat. Mus. Helminth. Collection No. 49166. Family Gorgoderidae 42. Probolitrema philippi Woolcock, 1935 Host: Squalus kirki Phillipps, dog fish; body cavity. Locality: Wellington. Specimen Deposited: U.S. Nat. Mus. Helminth. Collection No. 49167. A single specimen collected did not contain eggs but all organs except the uterus were well developed. Body size was 3.360 by 1.820 mm. The acetabulum was about 1½ times the diameter of the oral sucker. Woolcock's statement that the acetabulum was roughly twice the size of the oral sucker did not refer to transverse diameters, judging from her figure.

This species is previously known from a shark, Heterodontus philippi, at Port Philippi, Bay, Victoria, Australia. 43. Probolitrema clelandi Johnston, 1934 Host: Acanthias sp., dog fish; body cavity. Locality. Dunedin. A specimen of this species measuring about 19 by 10 mm. was given to me by Marion Fyfe of Otago University. Johnston's type specimen from Mustelus aniarcticus from South Australia was 10.5 mm. long. Family Accacoeliidae 44. Odhnerium calyptrocotyle (Monticelli, 1893) Yamaguti, 1934 Host: Mola mola (Linn), ocean sunfish; intestine. Locality: Wellington. Discussion: Several specimens of this trematode were recovered from a jar of cestodes collected from a sunfish by C. A. McCann of the Dominion Museum at Wellington who kindly placed them at my disposal. All specimens were considerably macerated but the dorsal “nuchal crest” of muscular nodules and the cap-like muscular plate on the dorsal side of the acetabulum clearly place the species in the genus Odhnerium Yamaguti, 1934. They agree with Yamaguti's (1934, pp. 509–510) description of O. calyptrocotyle and are probably that species. Dollfus (1935, pp. 208–209) takes the position that the generic name Odhneriam Travassos, 1921 makes Odhnerium a homonym, and renames the genus Mneiod-hneria Dollfus, 1935. This same situation has arisen a number of times (e.g. Haematoloechus Looss, 1899 and Haematoloecha Stal, 1874), and most parasitologis interpret the Rules of Nomenclature as permitting both such names. Therefore, I consider Mneiodhneria a synonym of Odhnerium It seems probable that Distomum foliatum Linton, 1898 is a synonym of O. calyptrocotyle as Yamaguti (1934) believed, but restudy of material from Woods Hole is needed. Dollfus tentatively considered it a second species in the genus. Family Bivesiculidae 45. Bivesiculoides otagoensis n.sp. (Figs. 62–63) Host: Plagiogenion rubiginosus Hutton; intestine. Locality: Dunedin. Holotype: U.S. Nat. Mus. Helminth. Collection No. 49143. Description (based on five specimens): These specimens were kindly given to me by Mr. L. O. Simpson of Otago University who collected them at Dunedin Length 2.940 to 3.528 mm.; width 0.990 to 1.554 mm. No spines were visible but some h id probably been lost as the specimens were slightly macerated. Mouth subterndnal, slightly dorsal or ventral; pharynx 0.105 to 0.139 mm long by 0.115 to 0.138 mm. wide; oesophagus from about the same length to almost twice length of pharynx; length of caeca not determined, as they soon became invisible; in one specimen one caecum was seen to overlap the testis a short distance. No. evidence that caeca ever extended posterior to testis. Testis large, ovoid, near posterior end of body, 0.655 to 0.716 mm. long by 0.531 to 0.616 mm. wide. In

one specimen it was abnormal, perhaps infected, and irregular in shape. Two vasa efferentia diverge from a single point at anterior end of testis, pass along the lateral edges of the cirrus sac, gradually enlarging and becoming slightly sinuous, meeting at anterior end of cirrus sac; a single, unpaired external seminal vesicle lacking. In one specimen, each vas efferens had swollen into a sac adjacent to the cirrus sac. Cirrus sac large, approximately at midbody, 0.577 to 0.924 mm. long by 0·385 to 0.716 mm. wide; containing an ovoid seminal vesicle, a small prostatic vesicle, a very wide pars prostatica filling almost half the sac, and well developed prostatic cells. Genital pore median, near midbody, large, its anterior edge with radiating muscles. This pore can become very large to permit protrusion of the pars prostatica as a tongue-like broad lobe. Ovary spherical or ovoid, to the right near posterior end of cirrus sac which it usually overlaps on the right. Mehlis' gland at medio-posterior end of ovary; seminal receptacle posterior to ovary, uterus with lateral coils between testis and cirrus sac; it may overlap testis but does not extend posterior to testis. Vitellaria more or less dendritic with irregularly shaped follicles, extending from posterior edge of pharynx usually to midtestis level sometimes to posterior end of testis, dorsal and ventral to caeca, confluent between intestinal bifurcation and cirrus sac. Eggs thin-shelled, usually collapsed. Uncollapsed eggs 91 to 93 by 53μ; collapsed eggs 80 to 91 by 42 to 49μ. Excretory vesicle V-shaped; anterior extent of arms not observed. Discussion: Yamaguti (1938) differentiated Bivesiculoides from Bivesicula because of its pretesticular uterus, longer caeca, and more extensive vitellaria. One of these differences is weakened by the presence of long caeca in Bivesicula australis Crowcroft, 1947, and perhaps the genus Bivesculoides is unjustified. The New Zealand species differs from Bivesculoides atherinae Yamaguti, 1938 in more anterior extent of the vitellaria, more dentritic form of the vitellaria, lack of a single external seminal vesicle, larger body size, and much larger eggs. Bivesicula australis has somewhat dendritic vitellaria which, however, do not reach the testis, and the uterus extends posterior to the testis. Le Zotte (1952) reports furcocercous cercariae for bivesculids and relates the family to the Azygiidae. Family Ptychogonimidae 46. Ptychogonimus megastoma (Rud., 1819) Lühe, 1900 Host: Raia nasuta Muller and Henle, skate; stomach. Locality: Portobello. Specimen Deposited: U.S. Nat. Mus. Helminth. Collection No. 49168. Discussion: Pour specimens were collected, all immature. Although no eggs were present, the reproductive organs were fairly well developed Body size was 3.052 to 3.682 by 1.162 to 1.330 mm. Sucker ratio was 1:0.76 to 0.80. No character of specific value could be found to separate these specimens from P. megastoma which occurs in a variety of selachians (dog fishes) in the European North Atlantic and Mediterranean as far south as Mauritania. I believe it has not been reported from the Pacific. Raia nasuta is probably not the normal host since the specimens were immature and the species is hitherto known only from dog fishes. Metacercariae are known from crabs.

Family Syncoeliidae 47. Syncoelium thyrsitae (Crowcroft, 1948) Yamaguti, 1953 Synonym: Copiatestes thyrsitae Crowcroft, 1948 Host: Thyrsites atun (Euphrasen), barracouta. Localities: Wellington, Portobello. Specimen Deposited U. S. Nat. Mus. Helminth. Collection No. 49169. Discussion: Crowcroft (1948) described this species in excellent detail. His genus Copiatestes, however, does not appear to differ essentially from Syncoelium Looss, 1899 which also has testes, ovary, and vitellaria divided into separated lobes. Yamaguti (1953a) considered it a synonym of Syncoelium. The genus Otiorema Looss, 1899 is related but has side brandies on the caeca and very numerous lobes of all the gonads. Both genera occur attached to the gill rakers of fishes, the type species of both genera occurring on sharks. Lloyd and Guberlet (1936) describe a Syncoelium species identified by them as S. filiferum (Sars) from the gills of the Pacific salmon, Oncorhynchus gorbuscha and O. nerka, in Puget Sound, Washington. Sars (1885) and Leuckart (1889) described Distomum filiferum from immature specimens which Sars collected from the body cavity of Schizopods (Thysanoessa gregaria and Nematoscelis megalops) in the South Atlantic. Leuckart notes the locality as “south of the Cape.” Odhner (1911, p. 527) states that D. filiferum is a second species of Syncoelium differing from S. ragazzii (Setti, 1897) Looss, 1899 in possessing 18 rather than 11 testes. Lloyd and Guberlet identified their specimens from the salmon as S. filiterum on the basis of the 18 testes then characteristic of the species. In view of Crow-croft's Antarctic species, it now appears doubtful if species in this genus can be identified without fully mature specimens. The Antarctic specimens collected by Sars from Crustacea agree equally well with either S. thyrsitae or the Puget Sound material. Considering the geographical location, it seems more likely that Growcroft had S. filiferum but until the question can be studied further the name S. thyrsitae will be retained. A third species named in the genus is S. katuwo Yamaguti, 1938 from the gills of Euthynnus pelamys from the Japanese Pacific. This species appears to me to be the same as the one studied by Lloyd and Guberlet. Yamaguti (1938a, p. 70) states it “differs chiefly in egg size,” but his egg measurements of 36 to 42 by 24 to 27μ do not differ much from the 40 to 50 by “about” 30μ reported by Lloyd and Guberlet. However, as noted above, Lloyd and Guberlet were probably unjustified in identifying their material as S. filiferum (Sars). It therefore seems best to consider the North Pacific species as S. katuwo with the “S. filifcrum” of Lloyd and Guberlet (1936) a synonym. S. thyrsitae is very similar to the North Pacific species. It does possess papillae on the forebody which are not described in S. katuwo. But in extended or slightly macerated specimens perhaps these papillae would not be detected. Eggs of S. thyrsitae are described as 25 to 30 by 17 to 21μ and the largest ones in my material are 30 by 18μ; in S. katuwo eggs are 36 to 42 by 24 to 30μ. This small but distinct difference seems to be the chief difference between the two species.

Family Hemiuridae 48. Ectenurus lepidus Looss, 1907 Hosts: Helicolenus pervoides Richardson, sea perch; stomach. Trachurus novae-zelandiae (Richardson), horse mackerel; stomach. Locality: Wellington. Specimen Deposited: U.S. Nat. Mus. Helminth. Collection No. 49170. Discussion: A total of six specimens were collected, five of them from the mackerel. Two of these five were from the stomach of a partially digested, small mackerel, probably T. novae-zelandiae, from the stomach of a kahawai, Arripis, trutta. A few minutes later that specimen might have seemed to be a parasite of Arripis. Probably some of the host records of Looss represent transient “infections” from a food fish. The specimens agree with characters described for E. lepidus although the dorso-lateral preoral papillae are inconspicuous and not always evident perhaps because of flattening of specimens in killing. The “short and thick” sinus sac figured by Looss is evidently in a contracted state In my specimens with extended forebody it is longer but does not reach the acetabulum. Prostatic cells occur only around the anterior third of the ejaculatory duct. Sucker ratio was 1: 2.8 to 3 compared with the described 1 : 2.5 Eggs are yellow-shelled when mature and measure 18 to 21 by 9 to 10μ. E. virgulus Linton, 1910 is a related species but differs in having a longer sinus sac and in addition prostatic gland cells occur around the male duct near the seminal vesicle and not near the sinus sac. E. lepidus is known from mackerel and other fishes at Trieste in the Mediterranean and from the horse mackerel, Trachurus trachurus, at Aberdeen, Scotland, and now from New Zealand. 49. Lecithochirium genypteri n.sp. (Figs. 64–66) Hosts: Genypterus blacodes (Bloch and Schn.), ling; stomach, type host Trachurus novae-zelandiae (Richardson), horse mackerel; stomach; one specimen, immature. Locality: Wellington. Holotype. U.S. Nat. Mus. Helminth. Collection No. 49144. Description: This trematode occurred in very large numbers in the ling More than 50 specimens were examined; measurements taken of 10. Body length 2·000 to 3.052 mm.; greatest width, near posterior end, 0.672 to 0·980. Ecsoma when completely retracted 0.570 to 0.910 mm., but when partially or wholly extended 0·700 to 2.268 mm or up to almost body length Forebody 0.574 to 1.050 mm. or from about ¼ to almost ½ body length, usually about ⅓. Preoral lip conspicuous. Oral sucker 0.192 to 0.277 mm. in transverse diameter; acetabulum 0·323 to 0·515 mm.; sucker ratio 1.1.7 to 1·9. Oral sucker (Fig. 65) with two conspicuous lateral pairs of muscular lobes or humps within the oral cavity. Preacetabular pit conspicuous, round, with distinct margin surrounded by gland cells. Intestinal caeca may or may not enter ecsoma, usually not, and for not more than half length of ecsoma.

Genital pore median, a transverse slit, opposite base of pharynx. Testes symmetrical, lateral, overlapping posterior portion of acetabulum, rarely only reaching posterior edge of acetabulum. Seminal vesicle an elongated tube more or less distinctly tripartite; its posterior end usually near midacetabular level but varying from the anterior edge to near posterior edge of acetabulum. Prostatic vesicle (Fig. 66) cylindrical, external to sinus sac. Sinus sac (Fig. 66) ovoid, containing a large ejaculatory vesicle and a curved tubular sinus. Ovary ovoid, to the left, posterior to left testis from which it is usually separated by a short space. Viteilaria 3- and 4-lobed; lobes as wide or wider than long. Uterus usually not entering ecsoma but it may do so for a short distance. Eggs 15 to 19 by 8 to 11μ. Discussion: The type species of Lecithochirium Lühe, 1901 is L. rufoviride (Rud., 1819) Lühe, 1901, best known from the description and figures of Looss, (1907). It is characterized by one pair of hump-like thickenings projecting into the lumen of the oral sucker, by a well defined preacetabular pit, an “ejaculatory vesicle” rather than a “prostatic vesicle” in the sinus sac (Looss' Fig. 42); short vitelline lobes and subequal suckers. L. gravidum Looss, 1907 was similar except in sucker ratio. The genus now contains at least 20 species some of which are doubtful members of the genus. Considerable confusion, particularly with the relatet genus Sterrhurus, exists. The hump-like elevations in the oral cavity do not occur in most species described in Lecithochirium and, for a time, the chief characters used to separate the genera was the presence or absence of the preacetabular pit. But this pit is sometimes difficult to observe as it is weakly developed in some species Yamaguti's (1942) L. macrostoma and L. carangis lack both oral elevations and preacetabular pits. Crowcroft (1945) suggested that the flat-walled “ejaculatory vesicle” within the sinus sac characterize the genus Sterrhurus while the “prostatic vesicle” with cellular wall characterize Lecithochirium. He states (p. 46): “In all the adequately described species of Lecithochirium the bladder within the muscular pouch or sinus sac is a portion of the pars prostatica. I cannot reconcile this view with Looss' Figures 42 and 43 of L. rufoviride showing a thin-walled bladder which, although labeled “PrBl,” is actually what is now termed an “ejaculatory vesicle.” The cylindrical prostatic vesicle opens into it exactly as in L. genypteri. The excellent redescription of L. rufoviride by Jones (1943) does not add much light to this particular point. The figure given, like the one by Looss, shows the internal vesicle as lined with a membrane and not by cubical cells as in the pars prostatica even although it is described as a “prostatic vesicle lined by a membrane similar to that of the pars prostatica.” On the other hand, Looss' Fig. 41 of Sterrhurus imocavus shows the bladder to be a prostatic vesicle. The cellular lining of the vesicle is not evident in his figure of S. musculus, the type species of Sterrhurus. Looss did not seem to attach importance to this character. Actually, the wall of the sinus sac of some species of Lecithochirium species is more or less open posteriorly and seems partially to enclose one end of the prostatic vesicle. In any case, L. genypteri is more similar to the type species and to L. gravidum than is any species yet named in the genus. It possesses the oral elevations and has almost identical sinus sac and preacetabular pit. In sucker ratio, a rather constant character, it is similar to L. gravidum from which it differs only in having two pairs (rather than one pair) of elevated lobes in the oral cavity;

in slightly smaller eggs; and in somewhat shorter vitelline lobes. It would have been identified as L. gravidum except for the four evident oral lobes. The genus Synaptobothrium von Linstow, 1904 with S. caudiporum (Rud., 1819) as type (and Lecithochirium caudiporum (Rud.) Lühe, 1901 and S. copulans von Linstow, 1904 as synonyms), has often been considered a synonym of Lecithochirium. It is recognised by Dollfus (1953) in the sense of Looss (1907). Dollfus stresses the following characters: cavity of oral sucker without humps; no muscular rectangular preoral lip; “cirrus sac” not pyriform but cylindrical; male duct not dilated into a vesicle within the sac; and eggs reniform when seen in profile. A preacetabular pit is present. Obviously, the genus Lecithochirium is in a very unsatisfactory state. There are so many variations and combinations of characteristics that probably only one or a very few should be arbitrarily chosen to characterize the genus. One or more of the following three seem most appropriate. the presence or absence of a preacetabular pit; the presence or absence of elevations in the wall of the oral cavity, or the character of the male vesicle within the sinus sac. Most of the species named do not possess the humps in the oral cavity. L. synodi Manter, 1931 lacks any kind of vesicle in the sinus sac as well as the oral cavity humps and hence is much like “Synaptobothrium” but it does have a preoral lip and non-reniform eggs. A difficulty in accepting Crowcroft's suggestion of a “prostatic vesicle” versus an “ejaculatory vesicle” is that, as noted above, the type species of Lecithochirium, L. rufoviride, has an “ejaculatory vesicle” rather than the “prostatic vesicle” assumed by Crowcroft. Also, this character is not made clear in some descriptions of species. Probably the most easily detected character is the preacetabular pit. The permanence of the humps in the oral cavity of L. genypteri suggests these might be a valid generic character. A major taxonomic operation is needed on the more than twenty species named in the genus Lecithochirium. Many changes in names would result and such a revision will not be attemtped here. I am inclined to remove from the genus all species lacking a preacetabular pit. A more restricted Lecithochirium could be limited to smooth-bodied hemiurids, with ecsoma, with short vitelline lobes, with preacetabular pit, with humps in the oral cavity, with tripartite seminal vesicle, and with ejaculatory vesicle within the sinus sac. Only L. rufoviride, L. gravidum, and L. genypteri would fit into such a genus. In view of the above discussion, Lecithochirium lycodontis Myers and Wolfang, 1953 is more like Sterrhurus than like Lecithochirium but it may well deserve a separate genus as the authors suspected. 50. Lecithochirium flexum n.sp. (Figs. 67–70) Host: Leptocephalus conger (Linn.), conger eel; stomach. Locality : Wellington. Holotype: U.S Nat. Mus. Helminth. Collection No. 49145. Description (based on seven specimens, with measurements on three. These trematodes occurred in small numbers with numerous Tricotyledonia genypteri in two of three conger eels examined). Body very thick muscular, contractile. Forebody bent sharply ventrally so that, unless forcibly straightened, its anterior tip reaches acetabulum (Fig. 68). Only one specimen (Fig. 67) 5.012 mm. long.

had a straightened forebody. Body length 4·214 to 5·012 mm. long, 1.330 to 1·596 mm. wide, almost equally wide along entire length, both ends broadly rounded Ecsoma entirely retracted in all specimens. Preacetabular pit inconspicuous, with semicircular edge. Very muscular, well developed, preoral process, more or less truncated, without definite sucker. Suckers large, subequal in size. Oral sucker 0.756 to 0.938 mm. wide, without oral elevations; acetabulum 0.882 to 0·980 mm. wide; sucker ratio 1 :1·05 to 1·18 Forebody 1·288 mm. in the 5.012 holotype Pharynx 0.231 mm. long by 0.239 mm. wide in the holotype. Caeca rather sinuous, ending a little beyond and to the side of base of ecsoma, not entering ecsoma. Genital pore median, at a level from midpharynx to slightly anterior to posterior edge of oral sucker. Testes rounded, symmetrical, partly overlapping posterior edge of acetabulum, far apart. Seminal vesicle tripartite, its base ending between anterior fourth of acetabulum to slightly posterior to acetabulum. Sinus sac broadly ovoid, not definitely enclosed at posterior end, containing a straight sinus tube and a rounded ejaculatory vesicle. No prostatic vesicle present. Ejaculatory and seminal vesicles connected by a narrow tube surrounded by prostatic cells. Ovary transversely ovoid, posterior to left testis but separated by uterine coils. Vitelline tubes considerably longer than wide, irregular in shape, not extending far but often bulging or bent to give a lumpy appearance, sometimes forked near tip (Fig. 70), usually four on one side, three on the other, in one case five and three. Uterus not entering ecsoma. Eggs 19 to 23 by 11 to 13μ. Excretory system not observed. Discussion : This trematode is unusual in its flexed forebody, its subequal suckers resulting from the very large oral sucker; its tightly clumped, rather “lumpy.” vitelline tubes, and absence of a prostatic vesicle. L. rufoviride, also from the conger, has a similar sucker ratio, but has elevations in the oral sucker, a prostatic vesicle, and short vitelline lobes. L. flexum, like Tricotyledonia genypteri Fyfe, 1954 is a very powerful trematode requiring great pressure to prevent rounding up into a contracted mass when being killed. The name flexum refers to the constant posture of folding the fore-body ventrally. Specimens can be recognized by this character alone. 51. Lecithochirium conviva Lüuhe, 1901 (Figs 71–72) Host Leptocephalus conger (Linn), conger eel; stomach. Locality. Wellington. Specimen Deposited U. S. Nat Mus. Helminth. Collection No. 49171. Discussion. Lühe (1901) gave a rather incomplete description of L. conviva based on five specimens found together with “L. fusiforme” (= Sterrhurus fusiforme) and L. rufoviride from Rudolphi's collection from the conger eel. No figure was given. So far as I can discover no further description or reference to L. conviva has been made. Lühe stated that the species was like other Lecithochirium species except that the vitellaria were compact and unlobed as in Derogenes. He believed that Olsson's (1876) “Distomum grandiporum Rud.” from Scandinavia was this species. Lühe's measurements were: body size 3 to 3.45 by 1.2 to 1.5 mm. Oral sucker 0·3 to 0.33 mm.; acetabulum 0.65 to 0.70 mm.

Fig. 67—Lecithochirium flexum from Leptocephalus conger. Ventral view; flattened specimen. Fig. 68—Anterior end of L. flexum. showing the usual flexing of the forebody. Ventral view. Figs. 69–70—Outline of ovary and vitelline tubes of L. flexum Fig. 71—Lecithochirium conviva from Leptocephalus conger. Ventral view of forebody. Fig. 72—Posterior portion of body of L. conviva showing vitellaria. Ventral view Fig. 73—Lecithochirium australis from Thyrsites atun. Ventral view. Fig. 74—Forebody of L. australis. Ventral view Fig. 75—Lecithocladium excisum from Caesioperca lepidoptera. Lateral view.

A single specimen was found together with numerous Tubulovesicula angusticauda and a few Derogenes varicus. Measurements were: body 2.338 by 0·952 mm. Ecsoma 1.288 mm. Forebody 0.798 mm. Oral sucker length 0.323 mm.; acetabulum length 0·616 mm. Ratio of lengths 1 :1·9. Eggs 17 to 20 by 9 to 10μ. Since a complete description of L. conviva is lacking and my material is a single specimen, its identification is tentative. The completely unlobed vitellaria constitute a marked characteristic. The terminal genital organs are exactly as in L. genypteri and it is possible the specimen is an aberrańt form of that species. However, more than 50 specimens of L. genypteri all show lobing of the vitellaria. The specimen of L. conviva seemed to have only one pair of oral elevations, lacked a preoral extension of the body, and the preacetabular pit was broad, more open, and without gland cells. 52. Lecithochirium australis n.sp. (Figs. 73–34) Host: Thyrsites atun (Euphrasen), barracouta; stomach. Locality: Wellington. Holotype: U.S. Nat. Mus. Helminth. Collection No. 49146. Description (based on a single specimen): Body length 3.710 mm., about equally wide posterior to acetabulum; width 0.980 mm. Ecsoma length 1.008 mm. Forebody 0·980 mm. Preacetabular pit large, conspicuous but with no gland cells evident. Oral sucker 0.308 mm. in transverse diameter; acetabulum 0·639 mm.; sucker ratio 1 : 2. Pharynx 0.152 by 0·152 mm. Caeca narrow in forebody becoming wider and extending into ecsoma about half its length. Genital pore median, fairly large but inconspicuous, opposite anterior half of pharynx. Testes longer than wide, oblique, separated by a coil or two of the uterus; anterior testis not quite reaching acetabulum. Seminal vesicle tripartite, overlapping anterior fourth of acetabulum; prostatic gland cells very few and small, surrounding a very short, swollen, thin-walled pars prostatica. Sinus sac (Fig. 74) broad and very thin-walled, 0.247 mm. long by 0.178 mm. wide, containing a small ovoid prostatic vesicle and very large, thin-walled, vesicular cells. Genital sinus short, straight, longitudinally striated in its basal half; metraterm entering it just anterior to prostatic vesicle. Ovary transversely ovoid, slightly to the right of midline, separated from posterior testis by two or three coils of the uterus. Vitellaria with lobes somewhat longer than wide; left vitellarium with four lobes; right seemingly with two lobes but since it faces laterally, the third lobe is probably concealed. Uterus not entering ecsoma. Eggs thin-shelled and packed tightly in uterus; 15 to 17 by 8 to 9μ. Discussion: This species is very similar to L. magnaporum Manter, 1940, from Paralabrax, Euthynnus, and Seriola in the Galapagos Islands. These two species and L. muraenae Manter, 1940 differ from all others in the genus in the character of the sinus sac which is broad and contains large, transparent cells. The similarity to L. magnaporum includes almost identical sucker ratio, preacetabular pits, arrangement of gonads, extent of uterus, egg size, and some details of the sinus sac. However, L. australis is more than twice larger in body size, the sinus sac is longer than wide, and the genital pore lacks the conspicuous radiations which occur in L. magnaporum. The pointed ends of the eggs of

L. magnaporum are perhaps due to the processing of specimens with such thin-shelled eggs. L. muraenae has a larger prostatic gland, shorter vitelline lobes, larger acetabulum, more symmetrical testes, and prominent folds in the genital sinus. L. priacanthi Yamaguti, 1953 lacks a sinus sac, has both a “prostatic vesicle” and “ejaculatory vesicle,” and has wider eggs. L. longicaudatum Yamaguti, 1953 does not have a preacetabular pit and may perhaps belong more appropriately in the genus Sterrhurus or Stomachicola. 53. Tricotyledonia genypteri Fyfe, 1954 Hosts: Genypterus blacodes (Bloch & Schn.), ling; stomach; Leptocephalus conger (Linn.), conger eel; stomach. Localities: Wellington, Portobello. Specimen Deposited: U.S. Nat. Mus. Helminth. Collection No. 49172. Discussion: Large numbers of this very muscular hemiurid were collected. Immature specimens were found in the stomach of Merluccius sp; Parapercis colias (Forster), blue cod; Polyprion oxygeneios (Bloch & Schm.), groper; and Trachurus novae-zealandiae (Richardson), horse mackerel. This trematode is easily recognized by the distinct sucker anterior to the oral sucker. 54. Lecithocladium excisum (Rud., 1819) Lühe, 1901 (Fig. 75) Hosts Caesioperca lepidoptera (Forster), red perch; intestine; Paraperca colias (Forster), blue cod; stomach. Locality. Wellington. Specimen Deposited: U.S. Nat. Mus. Helminth. Collection No. 49173. Discussion: One or two specimens from each of these hosts were all immature, the largest (from the blue cod) having a body length of 1.655 mm They are mature enough to show all characters of the genus Lecithocladium. The oral sucker is distinctly larger than the acetabulum, with a ratio occurring only in L. excisum. The neck hump is not evident, but Dawes (1947, p. 285) notes that it does not occur on immature specimens 1.5 mm long. Uterine coils have started to develop but do not enter the ecsoma. The caeca barely enter the ecsoma but might do so more as the body grows. Adults should be looked for in some mackerel. This species is widely distributed in mackerels of the Northern Hemisphere being reported from the Mediterranean, Baltic Sea, North Sea, North Atlantic, Woods Hole, Massachusetts, and Japan. Immature specimens have been reported from a variety of fishes. 55. Lecithocladium magnacetabulum Yamaguti, 1934 Synonym: Lecithocladium pagrosomi Yamaguti, 1934 Host. Pagrosomus auratus (Forster), snapper. Locality Wellington. Specimen Deposited U.S. Nat. Mus. Helminth. Collection No. 49174. Discussion: Seven specimens were studied and measured Body length without ecsoma was 1·400 to 1.960 mm. The ecsoma extended 0.490 to 1.960 mm. so

that the total length was 1.890 to 3.778 mm. Sucker ratio 1:1.2 to 1.5. The uterus extended into the ecsoma in all specimens and the vitellaria did so in four. Unusual variation in egg size occurred; two specimens had eggs 19 to 22 by 13 to 15μ; in two other specimens eggs were 27 to 28 by 13 to 15μ; in one specimen eggs were up to 30 by 15μ; in others the eggs were intermediate (23 by 10μ) or varied from 22 to 28 by 12 to 14μ. Thus, range of egg size must be at least 9 to 30 by 9 to 15μ. Yamaguti (1934, p. 483) distinguished L. pagrosomi from L. magnacetabulum, found in the same species of host, on the basis of smaller acetabulum and smaller eggs. He did not state exact sucker ratios but the type specimen of L. magnacetabulum had a 1: 1.55 sucker ratio as compared with 1:1.2 to 1.25 for L. pagrosomi. My seven specimens had sucker ratios of 1 : 1.2 to 1.5 thus almost covering the differences between the species. Egg sizes were sometimes practically as small as in P. pagrosomi but also reached 30 by 15μ or fully the size of those of P. magnacetabulum (27 to 33 by 15 to 16μ). No clear distinction of species appears in the terminal reproductive ducts although the genital pore in my specimens seems actually to open on the inside of the ventral edge of the mouth cavity. The length of the seminal vesicle varied from 0.220 to 0.308 mm. It can almost reach the acetabulum or be separated by almost the full length of the pars prostatica (about twice length of the vesicle). The posterior end of the sinus sac varies from near the anterior to near the posterior edge of the acetabulum. The pars prostatica is often coiled but appears to be about twice the length of the seminal vesicle. Its cells become reduced in size or number in its anterior portion. Because the New Zealand specimens show characters intermediate between L. magnacetabulum and L. pagrosomi, the latter is considered a synonym. Yamaguti's figures show the acetabulum of L. magnacetabulum occupying almost all the diameter of the body in contrast to the condition in pagrosomi. My specimens are more like pagrosomi in this character. More information is needed on the extent of variation in this character. 56 Lecithocladium seriolellae n.sp (Figs 76–77) Hosts: Seriolella brama (Gunther); warehou, type host, stomach; Cyttus australis (Richardson), boar fish, stomach. Locality. Wellington (Seriolella) and Port Chalmers (Cyttus) Holotype: U. S. Nat. Mus. Helminth. Collection No. 49147. Description (based on 15 specimens, with measurements on six). Length of body (without ecsoma) 1.344 to 1.736 mm. ecsoma may be extended 0.231 to 0.385 mm.; body width 0.339 to 0.547 mm. Denticulations present. Oral sucker 0.175 to 0.207 mm. in transverse diameter; acetabulum 0.205 to 0.269 mm. in diameter; sucker ratio 1:1.15 to 1.32 Pharynx 0.118 to 0.133 mm. long by 0.065 to 0.087 mm. wide. Oesophagus very short; caeca extending directly forward a short distance before turning backward; at the point of bifurcation near the dorso-posterior edge of the pharynx is a dorsal sac-like inflation of the oesophagus from the anterior median edge of which the caeca arise each caecum is also sac-like at its origin so that three sac-like formations are seen close together (Fig. 77). The oesophageal sac has a more refractive lining. The caeca may or may not enter the ecsoma but not more than half its length.

Genital pore median or submedian, very close to ventral edge of the mouth. Testes oblique, often overlapping slightly, about at mid-body level. Seminal vesicle with very thick, muscular walls; variable in size, 0.167 to 0.342 mm. long by 0·095 to 0·190 mm. wide; filling most of intercaecal space between testes and acetabulum. Pars prostatica usually sinuous, S-like, but affected by contraction of body. It is apparently not much longer than the seminal vesicle but the latter varies considerably in length. Sinus sac beginning opposite anterior half of acetabulum, curving slightly to genital pore. Ovary ovoid, slightly larger than testes, close to testes except in most gravid specimens in which a coil or two of the uterus may come between them. Vitelline tubes long, extending almost transversely, tending to curve around the caeca to end dorsally; four on the right, three on the left; most posterior tube on the right tends either to be median or to bend across the body ending on the left side. Seminal receptacle not observed Uterus never entering ecsoma although in the most gravid specimens it may encroach slightly into the body on each side of the base of ecsoma. Eggs 19 to 22 by 10 to 14μ. Excretory crura uniting dorsal to posterior edge of oral sucker in most specimens; in one specimen the ends of the two vessels appeared to run parallel and in close contact but without union. Discussion: This is a small-sized species of Lecithocladium, only L. carultum Chauhan, 1945, L. scombri Yamaguti, 1953, and L. johnii Yamaguti, 1938 being nearly as small. It differs from all species in the genus except L. brevicaudum Srivastava, 1937 in that the uterus does not enter the ecsoma, and the caeca do so only to slight extent. L. johnii is described as lacking cuticular denticulations, supposedly a generic character, and differs also in more posterior genital pore, more separated testes, and uterus entering the ecsoma. L. seriolellae is probably most similar to L. carultum which is, however, not fully known being described from a rather young specimen. In L. carultum the sinus sac does not reach the acetabulum; there are four vitelline tubes on each side; and the caeca extend well into the ecsoma. L. carultum is from the west coast of India. L. brevicaudum Srivastava, 1937 is described as lacking all cuticular scales and it has a thin-walled seminal vesicle, thus being unlike all other species and resembling Tubulovesicula except for the shape of the seminal vesicle. L. scombri has a notched oral sucker, a longer pars prostatica. and even the vitelline lobes enter the ecsoma. L. longicaudum was described by Tseng in March, 1935 from the sea-eel from the Tsingtao market. As noted by Chauhan (1945) it belongs in the genus Stomachicola, Furthermore, it appears to be identical with S. muraenesocis Yamaguti, 1934 collected from the same host, Muraenesox cinereus, from the Inland Sea. Chauhan (1945) reports it from M. talabonoides from the Bombay Coast. L. excisum (Rud., 1819) Lühe, 1901, type species of the genus, is now recognized from the Mediterranean, North Atlantic, and Japan Synonyms are L. excisiforme Cohn, 1903; L. gulosum (Linton, 1899) Looss, 1907; L. cristatum (Rud., 1819) Looss, 1907; and L. crenatum (Molin, 1859) Looss, 1907. In addition to L. seriolellae, the following species occur in the genus. L. angustiovum Yamaguti, 1953; L. annulatum Chauhan. 1945: L. brevicaudum Srivastava, 1938; L. carultum Chauhan, 1945; L. excisum (Rud. 1819) Lühe,

1901; L. glandulum Chauhan, 1945; L. harpodontis Srivastava, 1937; L. johnii Yamaguti, 1938; L. magnacetabulum Yamaguti, 1934; L. megalaspis Yamaguti, 1953; L. parviovum Yamaguti, 1953; L. psenopsis Yamaguti, 1934; L. scombri Yamaguti, 1953. 57. Tubulovesicula angusticauda (Nicoll, 1915) Yamaguti, 1934 (Fig. 78) Hosts: Chelidonichthys kumu (Lesson and Garnot), gúrnard; stomach; Cyttus australis (Richardson), boar fish; stomach; Helicolenus percoides (Richardson), sea perch; stomach; Latridopsis ciliaris (Forster), moki; stomach; Leptocephalus conger (Linn.), conger eel; stomach; Macruronus novae-zealandiae (Hector), whiptail; stomach: Merluccius gayi (Giuchenot), whiting; stomach; Physiculus bachus (Bloch & Schn.), red cod; stomach; Polyprion oxygeneios (Bloch & Schn) Scorpaena cruenta Richardson, scarpee; stomach. Localitys. Wellington and Portobello. Specimen Deposited. U.S. Nat. Mus. Helminth. Collection No. 49175. Discussion: This species was described by Nicoll on the basis of a single specimen from Muraenesox cinereus in Australia. My material agrees with the somewhat limited description in body size, egg size, and in that the pars prostatica begins at or near the anterior border of the acetabulum. In 10 specimens measured, the sucker ratio was 1 : 1.57 to 1.88 as compared with 1.2 in Nicoll's specimen. Egg size was 26 to 32 by 19 to 23μ in all specimens except the one from the conger eel in which the eggs were 38 to 46 by 23 to 26μ. This would suggest a different species but no other differing character could be detected. Perhaps such specimens should be considered a subspecies. Unless egg size is markedly different, specific distinctness should probably require another point of difference. Too many species have been named in the genus Tubulovesicula because variable characters are not yet fully appreciated. Judging from 12 specimens collectéd, the number and arrangement of the vitelline tubes show variations which have been used to characterize species. The number of tubes is either seven or eight and they may be arranged in various ways. The usual 3 right and 4 left occurred in five specimens; but two specimens had 4 right and 3 left; three had 4 on each side: one had 3 on each side with 1 median; one had 6 right and 2 left. The variations were not associated with species of host. Measurements on 10 specimens were: body length 2.100 to 3.818 mm.; width 0.631 to 1.036 mm.; total length of ecsoma 0.420 to 1·776 mm. Oral sucker diameter 0.169 to 0.308 mm.; acetabulum diameter 0.300 to 0.523 mm.; sucker ratio 1.1 57 to 1.88. Pars prostatica 0.501 mm. long in a 3.612 mm. specimen. The genital pore is a wide slit at midpharynx level; the atrium short, wide, and with very fine papillae. Sinus sac well developed. A metraterm is present. Eggs usually 26 to 34 by 19 to 23μ; in one specimen 38 to 46 by 23 to 26μ Extension of the uterus into the ecsoma in this genus, as noted by Yamaguti, probably varies with age. In two of twelve specimens the uterus did not enter the ecsoma, in all the others it entered a short distance up to about ½ ecsoma length in one case. Nicoll's specimen from Australia was probably a young individual.

In all my specimens the pars prostatica was longer than shown in Nicoll's figure but as in his specimen it did not reach much if any beyond the anterior edge of the acetabulum. Yamaguti (1953) lias reported a single specimen of T. angusticauda from Sauridia argyrophanes in the Celebes, noting that it differs from Nicoll's specimen in position of the genital pore (just posterior to the intestinal bifurcation, thus more posterior than in the Australian material), position of the acetabulum (slightly more posterior), length of the pars prostatica (longer), and longer vitelline lobes. He did not figure his specimen. It seems to agree with the New Zealand material except in more posterior position of the genital pore. In both Nicoll's and Yamaguti's material the seminal vesicle does not extend posterior to the acetabulum while it does so in all of my specimens except in two which are contracted. More information regarding variation in the seminal vesicle particularly in Australia and Celebes is needed. The Genus. Tubulovesicula. The following revision of species in this genus is suggested. T. nanaimoensis (McFarlane, 1935) Manter, 1947 from a sole and a sculpin of British Columbia appears identical with T. lindbergi (Layman, 1930) Yamaguti, 1934 from Pleuronectidae and other fishes of Peter the Great Bay. The only difference evident from descriptions is a slightly larger egg size. It is here considered a synonym. T. pinguis (Linton, 1940) Manter, 1947 seemed so much like T. madurensis Nigrelli, 1939 that specimens were borrowed from the United States National Museum. The two specimens from the type host, Menidia notata at Woods Hole. Massachusetts, showed that gland cells occur along the entire length of the pars prostatica except for a definite break dorsal to the acetabulum. This species differed from all others in the genus in this character. It is considered to be a valid species. It seems probable, however, that at least some of the specimens reported by Linton from various other hosts at Woods Hole are different species. T. californica Park, 1936 from Enophrys bison at Dillon Beach, California, was described from a single specimen. Its eight vitelline tubes cannot now be considered distinctive. I cannot find significant differences between this species and T. spari Yamaguti, 1934, T. pseudorhombi Yamaguti, 1938, and T. muraenesocis Yamaguti, 1934, and therefore consider them all to be S. spari, type of the genus T. anguillae differs only in that the ecsoma is as long as the body. T. madurensis Nigrelli, 1940 from a deep sea scorpion fish of the Madeira Islands appears to be a synonym of T. lindbergi although its eggs are slightly smaller (18 to 25 by 12 to 15μ compared with 27 to 29 by 18 to 20μ) and the seminal vesicle somewhat broader. Although the localities are about as distant as possible, the common occurrence of deep-sea species of trematodes in distant cold waters of the northern or southern hemisphere has been noted (Manter, 1934). T. madurensis is considered a synonym of T. lindbergi.

Key To Species Of Tubulovesicula 1 (4) With prostatic gland cells from posterior edge of acetabulum 2 2 (3) Gland cells not interrupted opposite acetabulum T. lindbergi (Layman, 1930) 3 (2) Gland cells interrupted opposite acetabulum T. pinguis (Linton, 1940) 4 (1) With prostatic gland cells beginning at midacetabular level or more anterior 5 5 (6) Prostatic cells begin at or near anterior margin of acetabulum T. angusticauda (Nicoll, 1915) 6 (5) Prostatic cells begin near midacetabular level 7 7 (8) Acetabulum 3 × oral sucker T. magnacelabulum Yamaguti, 1939 8 (7) Acetabulum less than 3 × oral sucker 9 9 (10) Tail as long as body T. anguillae Yamaguti, 1934 10 (11) Tail shorter than body T. spari Yamaguti, 1934 Fig. 76— Lecithocladium seriolellae from Seriolella brama. Ventral view. Fig. 77—Forebody of L. seriolcllae. Dorsal view Fig. 78—Tubulovesicula angusticauda from Physiculus bachus Ventral view. Fig. 79—Sterrhurus lotellae from Lotella rhacinus Ventral view. Fig. 80— Terminal genital organs of S. lotellae. Ventral view. Fig. 81—Derogenes nototheniae from Notothenia macrocephala. Lateral view. Fig. 82—Forebody of D. nototheniae showing terminal genital organs. Lateral view. 58. Sterrhurus lotellae n.sp. (Figs. 79–80) Host: Lotella rhacinus (Forster), southern hake; stomach. Locality : Wellington. Holotype: U.S. Nat. Mus Helminth. Collection No. 49148. Description (based on a single specimen) : Body length 2.044 mm., width 0·693 mm. Ecsoma 0.785 mm long. Forebody 0.732 mm. long. Oral sucker 0.308 mm. in diameter, acetabulum 0.439 mm. Sucker ratio 1 : 1.42. Pharynx 0·114 mm. long by 0.129 mm. wide; caeca extend a short distance into ecsoma Genital pore a transverse slit at level of intestinal bifurcation. Testes diagonal a short distance postacetabular. Seminal vesicle tripartite, only slightly overlapping acetabulum, anterior segment with thick walls. Sinus sac (Fig. 80) ovoid, rounded anteriorly, extending dorsally and posteriorly Genital pore with circular sphincter muscles; genital sinus straight, thick walled; prostatic vesicle present, probably at least partly within sinus sac but perhaps dorsal to it. Ejaculatory vesicle lacking. Prostatic gland well developed partly dorsal to sinus sac Ovary transversely ovoid, posterior to left testis from which it is separated by a uterine coil. Vitellaria 3- and 4-lobed, lobes somewhat longer than wide. Uterus not entering ecsoma. Eggs 17 to 20 by 8μ. Discussion: In most respects this specimen is a typical Sterrhurus. A pre acetabular pit could not be seen. Crowcroft's (1946) suggestion of basing the genus on the presence of an ejaculatory vesicle would place this species in the genus Lecithochirium but as explained above this view is not being followed pending better knowledge of the type species of Sterrhurus. S. lotellae differs from all other species in the relatively large size of the oral sucker. The sucker ratio of 1:1.4 compares with at least a 1.2 ratio in other species. Although only a single specimen was collected, this difference seemed too great to disregard. Another feature not known in other species is the thick wall of the anterior segment of the seminal vesicle. Otherwise the species is like S. musculus which it resembles in egg size and in vitellaria. The name lotellae is for the host. 59. Derogenes varicus (O. F. Muller, 1784) Looss, 1901 Hosts: Caulopsetta scapha (Forster), flounder; Chelidonichthys kumu (Lesson & Carnot), gurnard; Cyttus australis (Richardson), boar fish; Cyttus novae-zealandiae (Arthur), silver dory; Genypterus blacodes (Bloch & Sch.), ling; Leptocephalus conger (Linn.), conger eel;

Macruronus novae-zealandiae (Hector), whiptail; Physiculus bachus (Bloch & Schn.), red cod; Scorpaena cruenta Richardson, scarpee. In all cases, the trematode occurred in the stomach. Localities: Wellington and Portobello. Specimen Deposited: U.S. Nat. Mus. Helminth. Collection No. 49176. Discussion: Derogenes varicus is a remarkable trematode in several respects. It has been reported from a very large number of species of marine fishes, although it usually occurs in small numbers within a single host. No trematode, so far as I know, has such a long list of host species (more than 50). One might suppose that with such lack of host specificity Derogenes varicus would be universally distributed throughout the seas of the world. Such is not the case. Wherever it does occur it seems to be common and found in a variety of hosts, but it was not found at all in the numerous shallow water fishes of Tortugas, Florida nor in the warm Pacific regions so far sampled. The author has examined some 40 species of fishes at Suva, Fiji without collecting D. varicus; Yamaguti (1952) does not report it from the Celebes; and the collections so far reported from the Red Sea or the Indian Ocean do not include it. Thus, it appears to be conspicuously absent in fishes of the warmer seas. On the other hand, it is apparently very common in marine fishes (1) of the Arctic and northern temperate seas both Atlantic and Pacific, and (2) in fishes of deep water even in the subtropics. At Tortugas, it was not found from less than 190 fathoms but occurred in 5 different species of fishes from that depth or below. Rees (1953) reports it from Iceland from 160 fathoms. Its presence at the Galapagos Islands (Manter, 1940, p. 430) is explained by the cold Humbolt current and by the massive upwelling off the South American coast giving the Islands cool waters (about 68°F). In New Zealand, Derogenes varicus shows a prevalence comparable to its occurrence in the North Atlantic. No other species was collected so many times. As in the North Atlantic, only a few specimens occurred in a single host. The life cycle of Derogenes varicus is not known. Probably the temperature limitations on its distribution operates through some of its intermediate hosts. It is probably a common world wide parasite of deep sea fishes, but also has a wide distribution in shallow but cold water fishes of both hemispheres. Peter Crowcroft has indicated (in correspondence) that it occurs in Tasmania. 60. Derogenes nototheniae n. sp. (Figs. 81–82) Host: Notothenia macrocephala Günther, maori chief; gills and stomach. Locality Wellington. Holotype: U.S. Nat. Mus. Helminth. Collection No. 49149. Description (based on nine specimens, with measurements on seven). Body smooth, cylindrical, about equally wide except pointed rather abruptly at each end. Length 1.302 to 2·300 mm.; thickness 0.208 to 0.346 mm. Acetabulum large, deep and protruding so that only a side view of specimens was seen Acetabulum approximately at midbody but either forebody or hindbody, if contracted, can be shorter than the other Forebody 0.501 to 0.966 mm. Oral sucker

length 0·115 to 0·177 mm.; acetabulum length 0·308 to 0·423 mm.; ratio of lengths 1 : 2·3 to 2·6. Lateral view of oral sucker shows a pointed tooth-like process at middle of edge of anterior lip and another on posterior lip. Pharynx rounded, slightly thicker than long, 0.053 to 0·076 mm. long by 0·060 to 0.84 mm. thick; oesophagus very short or lacking; caeca ending blindly just beyond posterior edge of vitellaria a little in front of posterior end of body; ends of caeca often obscured by eggs. Genital pore median opposite pharynx Testes rounded, oblique to almost tandem, separated from acetabulum by uterine coils, usually close together but rarely separated by a uterine coil. Seminal vesicle a long, sinuous tube reaching to or almost to anterior edge of acetabulum, length 0·171 to 0·304 mm. External prostatic vesicle elongate oval, much shorter than seminal vesicle, surrounded by large prostatic cells. Sinus sac (Fig. 82) pyriform, thick-walled, containing a rounded prostatic vesicle, small gland cells, and a straight genital sinus which projects into a very short atrium. Sinus sac 0·095 to 0·148 mm. long by 0·065 to 0.106 mm. wide. Ovary subspherical immediately posttesticular but sometimes separated by a uterine coil. Seminal receptacle not seen. Vitellaria compact, ovoid, sub-spherical, symmetrical or oblique, immediately postovarian. Uterus extending posterior to vitellaria and beyond ends of caeca, not quite reaching posterior end of body. Eggs without filaments, 28 to 32 by 15 to 19μ. Excretory pore ventral. subterminal. Discussion : D. nototheniae differs from all other species in the genus in that the seminal vesicle is much longer than the pars prostatica which is unusually short. Also, the eggs are smaller and thinner shelled. 61. Mitrostoma nototheniae n.gen., n.sp. (Fig. 83) Host. Notothenia macrocephala Günther, Maori chief; caeca and intestine. Locality : Wellington. Holotype: U.S. Nat. Mus. Helminth. Collection No. 49150. Description (based on four mature and one immature specimens). Hemi uridae without denticulations; without ecsoma; with paired, compact vitellaria (i.e., Derogenetinae). Body tapering anterior to acetabulum but otherwise almost equally wide and truncate at posterior end. Length 1.246 to 1·890 mm. A specimen 1.106 mm. long did not contain eggs. Width 0·462 to 0.630 mm. Body surface, except near anterior end, with a thick, clear, rugose cuticula. Forebody 0·300 to 0.448 mm. Oral sucker preceded by a transversely ovoid, weakly muscular lobe bearing the mouth. Oral sucker 0.115 to 0.154 mm. in transverse diameter. acetabulum 0.231 to 0.331 mm. in diameter. Sucker ratio 1 : 2 to 2.1. Acetabulum with sphincter muscles in anterior and posterior halves. Transverse diameter of oral lobe 0.131 to 0.192 mm. It is slightly wider but not as long as oral sucker. A conspicuous transverse, preacetabular pit with muscular rim surrounded by gland cells is present. Near posterior edge of acetabulum a thickened projection occurs on each side. These do not appear to extend across the body as a fold. Diagonal muscles from the sides of the acetabulum appear to end near them. They are inconspicuous in the type specimen. Pharynx about 0.072 mm. long by 0.076 mm. wide; oesophagus very short or lacking: caeca reach to near posterior end of body.

Genital pore submedian opposite posterior portion of pharynx. Testes ovoid, tandem, intercaecal, separated by uterus, anterior testis 0.131 to 0.192 mm. posterior to acetabulum or near midbody. Seminal vesicle a convoluted tube, entirely postacetabular. Pars prostatica long, glandular, from near intestinal bifurcation to a short distance posterior to acetabulum. Sinus sac short, pyriform, protrusible. Ovary ovoid, larger than testes, median, intercaecal, posttesticular, separated from testes by uterus. In young specimens, however, all the gonads are near together. Seminal receptacle pvriform. its saccular portion anterior to ovary; Mehlis' gland postovarian. Vitelline glands compact, unlobed. oblique, immediately postovarian. Uterus sending a coiling loop posterior to vitellaria. then coiling anteriorly along left side of body, extending between the gonads. Metraterm not observed. Eggs 23 to 27 by 11 to 14μ. Crura of excretory vesicle lateral to caeca in the forebody and uniting dorsal to pharynx. A nipple-shaped protuberance at posterior end of the type specimen was apparently an abnormality. The name Mitrostoma is from mitra, a cap and stoma, mouth referring to the peculiar cap-like lobe surrounding the mouth. The name nolotheniae is for the host. Diagnosis Of The Genus Mitrostoma: Derogenetinae with almost equally wide body, truncated posteriorly. A transversely ovoid, weakly muscular flap or lobe precedes the oral sucker and bears the mouth. Preacetabular pit glandular, with transverse opening. Testes preovarian, median, tandem, in posterior half of body, separated by uterus in mature specimens. Seminal vesicle a convoluted tube, postacetabular, pars prostatica very long, sinus sac small. Seminal receptacle present. Vitellaria oblique Type species. M. nototheniae Comparisons: This genus combines characters of several genera of Derogenetinae, in particular. Genolinea Manter, 1025; Theletrum Linton, 1910 and Opisthadena Linton, 1910 The oral lobe anterior to the oral sucker is unique, and a preacetabular pit, although occurring in some of the tailled hemiurids such as Lecithochirium and Brachyphallus, is not known, I believe, in this subfamily. The body rim or lateral projection near the acetabulum occurs in Theletrum, Opisthadena and in Bunocotyle Odhner, 1928, all of which, however, have a short pars prostatica and a sac-like seminal vesicle. Genolinea is probably the most closely related genus but it lacks the oral lobe, the preacetabular pit and the postacetabular rim or projection It does have a tubular seminal vesicle but it is much more anterior and the pars prostatica is short. Some species of Genolinea have the acetabular sphincter. 62 Gonocerca phycidis Manter, 1925 Hosts Coelorhynchus australis (Richardson), rat fish; stomach; Macruronus novae-zelandiae (Hector), whiptail, stomach; Merluccius quyi (Guichenot). whiting; stomach, Parapercis colias (Forster), blue cod; stomach; Scorpaena cruenta Richardson, scarpee. attached to head. Localities: Wellington and Portobello. Discussion: This species was described from Urophycis chuss from the coast of Maine and was later collected (Manter, 1934) from depths of 139 to 300 fathoms

at Tortugas, Florida where it infected Urophycis regius, Merluccius sp. and Coelorhynchus carminatus. Its rather common occurrence in New Zealand is of interest in furnishing another example of northern, deep-water, and southern distribution, and also in the fact that several of the hosts in the different areas are related. For example, species of Merluccius and Coelorhynchus both at Tortugas (in deep water) and in New Zealand are infected. Two other species occur in the genus Gonocerca, G. kobayshii (Layman, 1930) Manter, 1934* Yamaguti (1934: 499) notes that the original spelling “kobayashi” was a misprint. and G. crassa Manter, 1934. G. kobayshii is characterized by deeply lobed vitellaria. G. crassa was described from 13 different hosts from deep-water fishes at Tortugas. Later, it was reported from Coelorhynchus sp. from Japan by Yamaguti (1938: 137) and recently from Molva byrkelange from 160 fathoms from Iceland by Reese (1953). This species is very similar to G. phycidis. The size range of G. phycidis appears to be much greater than recorded. All my Tortugas specimens of G. crassa had diagonal or almost symmetrical testes as compared with the tandem testes of G. phycidis but Yamaguti states the testes can be diagonal or tandem in G. crassa. The chief difference beween the species is probably the more anterior position of the genital pore, opposite the oral sucker, in G. phycidis. As a result the prostatic gland partly overlaps or at least contacts the oral sucker, while it is definitely more posterior in G. crassa. The genital pore is inconspicuous in G. phycidis, and no genital cone is visible. New Zealand specimens are large for G. phycidis, being 2.822 to 7.140 mm. The larger specimens (from Merluccius and Scorpaena) would appear, in fact, to be too large to be the same species. But intermediate sizes occurred and proportions were the same in all Sucker ratio was 1 : 1.6 to 2; egg size 38 to 48 by 15 to 23μ. The large (7.140 mm.) specimen from Scorpaena occurred deeply embedded in the skin just below the eye Only the posterior half of the body protruded and the specimen was dissected out with some difficulty. It must have been attached there for some time. This specimen was also aberrant in possessing a single testis Another large specimen showed one testis partly disintegrated so that the single testis condition is probably an abnormality. 63. Genolinea anura (Layman, 1930) Yamaguti, 1934 Synonym. Brachyphallus anurus Layman, 1930 Host: Chironemus spectabilis (Hutton), red moki: caeca. Locality: Wellington. Specimen Deposited: U.S. Nat. Mus. Helminth. Collection No. 49177. Measurements of four specimens were as follows: Length 1.936 to 3.458; width at acetabular level, 0.708 to 0.939 mm.; forebody 0.630 to 0.840 mm.; postvitelline space, 0.322 to 0.504 mm. Oral sucker 0.192 to 0.246 mm. wide; acetabulum 0.547 to 0.678 mm. wide; sucker ratio 1 :2.5 to 2.84. Eggs 28 to 32 by 19μ. Discussion. The genus Genolinea was named by Manter (1925) from the halibut, Hippoglossus hippoglossus, from the Maine coast. MacFarlane (1936) reported the type species, G. laticauda Manter, 1925 from Scorpaenichthys marmotus, the giant marbled sculpin from British Columbia. Lloyd (1938)

named G. robusta from S. marmotus and from the ling cod, Ophiodon elongatus. from the coast of Washington. G. robusta was somewhat larger and thicker than G. laticauda but the sizes meet or overlap. The sphincter muscle's of the acetabulum were not described for G. laticauda. However, examination of paratype material of the latter species shows that these muscles are in fact present. It appears evident that G. robusta is a synonym of G. laticauda. Yamaguti (1934) noted that Brachyphallus anurus Layman, 1930 from “Cottidae, Hexagrammidae and Pleuronectidae,” as well as once from a salmon, from Petér the Great Bay, belonged in the genus Genolinea. Linton (1940) described “Genarches infirmus” from the Chinook salmon, Oncorhynchus tschawytscha, from California. However, since the caeca do not unite (at least in Linton's figure), this species cannot belong in Genarches. Linton's description is inadequate, and incorrect in stating that the prostate gland was within the cirrus sac. The almost linear position of the gonads in his figure suggests the genus Genolinea, but if the seminal vesicle is actually small and sac-like and the vitellaria usually transverse, the species may belong in the genus Derogenes. Genolinea manteri Lloyd, 1938 is very similar to G. anura, especially since the New Zealand specimens are intermediate in size between Lloyd's and Layman's. In both of the North Pacific forms the seminal vesicle extends to about midacetabular level, while in the New Zealand specimens it ends barely anterior to midacetabulum. This difference seems too slight to be more than individual variation. Layman records an egg size of 27 to 29 by 14 to 16μ for G. anura; my specimens had eggs 28 to 32 by 17 to 19μ; Lloyd reports 35 to 38 by 19 to 20μ for G. manteri. This difference in egg size seems to be the chief one between the two species. 64. Genolinea dactylopagri n.sp. (Figs. 84–85) Hosts: Dactylopagrus macropterus (Forster), tarakihi, type host; stomach; Latridopsis ciliaris (Forster), moki; stomach. Localities: Wellington and Portobello. Holotype: U.S. Nat. Mus. Helminth. Collection No. 49151. Description (based on 15 specimens, with measurements on seven) : Body elongate but muscular and little flattened, 1.722 to 3.388 mm. long by 0.539 to 1.274 nm. wide at acetabular level. Forebody 0.515 to 0.980 mm. or approximately ⅓ body length. Oral sucker 0.169 to 0.315 mm. in transverse diameter. Acetabulum large, round or slightly longer than wide, 0.431 to 0·916 mm. wide. Sucker ratio 1: 2.3 to 2.9. Pharynx 0.077 to 0.131 mm. long by 0.077 to 0.146 mm. wide; oesophagus short, caeca bowing outward then becoming more median dorsal to acetabulum, ending blindly near posterior end of body. Genital pore median or submedian from opposite posterior part of pharynx to just posterior to intestinal bifurcation Testes large, round, usually slightly diagonal, sometimes almost symmetrical, filling most of body immediately posterior to acetabulum. Sinus sac (Fig. 85) very large, ovoid to pyriform, usually slightly longer than wide; its fibrous wall without clear inner boundary; containing distally a long, tubular, muscular, distensible portion of the sinus, and two, small, thick-walled basal portions surrounded by small gland cells which seem to open between them. Pars prostatica well developed; a rather wide curved tube surrounded by a

conspicuous mass of gland cells which occupy a space almost equal to that of the sinus sac. Seminal vesicle entirely external, tubular, with more or less lateral coils between prostatic gland and acetabulum; overlapping anterior edge of acetabulum slightly. Ovary transversely ovoid, median or submedian, immediately posttesticular. Seminal receptacle globular, largely dorsal to left portion of ovary. Uterus with coils extending to or usually slightly beyond posterior edge of posterior vitellarium, then coiling forward to enter base of sinus sac. Vitellaria consisting of two large, compact, unlobed masses one behind the other, immediately post-ovarian. Sometimes the vitellaria are slightly oblique; the anterior one is wider than long being crowded between ovary and the other vitellarium. Postvitelline space 0·146 to 0·462 mm., somewhat variable but relatively short. One specimen showed an abnormality in complete lack of vitellaria although its very numerous eggs were normal. Eggs 28 to 34 by 13 to 19μ, usually 30 to 34 by 16 to 19μ. Excretory pore subterminal and dorsal; crura of the vesicle without marked convolutions, uniting dorsal to oral sucker. Bifurcation of the vesicle not observed. Discussion: The genera Genolinea Manter, 1925 and Leurodera Linton, 1910 are closely related. This species was at first considered to be in the genus Leurodera because the testes, although oblique, tended to be more lateral than tandem. However, Leurodera has a conspicuous loop in each excretory arm in the forebody, the anterior vitellarium is lateral to the ovary, prostatic gland cells are practically lacking, and the seminal vesicle is almost straight. Of these differences, the looped excretory ducts are perhaps most characteristic. The genus Theletrum Linton, 1910 is also closely related but has a deeply lobed anterior vitellarium. G. dactylopagri differs from other species in the genus in its very large, more posterior acetabulum and its less tandem testes which are closer to the acetabulum than in other species except G. montereyensis Annereaux, 1947 From the latter it differs in sucker ratio and in development of prostatic cells. Key To Species Of Genolinea 1 (2) Seminal vesicle extending posterior to acetabulum G. aburame Yamaguti, 1934 2 (1) Seminal vesicle not extending posterior to acetabulum 3 3 (4) Sphincter muscles in acetabulum G. laticauda Manter, 1925 4 (3) Sphincter muscles lacking in acetabulum 5 5 (8) Anterior testis close to acetabulum 6 6 (7) Sucker ratio 1: 2·3 to 2·9 G. dactylopagn 7 (8) Sucker ratio 1 1·56 G. montereyensis Annereaux, 1947 8 (5) Anterior testis well separated by uterus from acetabulum 9 9 (10) Eggs 35 to 38 by 19 to 20μ G. manteri Lloyd, 1938 10 (9) Eggs 27 to 32 by 14 to 19μ G. anura (Layman, 1930) Family Aporocotylidae Odhner, 1912 65. Cardicola coridodacis n.sp. (Figs. 86–87) Host: Coridodax pullus (Forster), butterfish; gills and coelom, probably from blood vessels. Locality: Wellington.

Fig. 83.—Mitrostoma nototheniae from Notothenia macrocephala. Fig. 84—Genolinea dactylopagri from Dactylopagrus macropterus. Ventral view. Fig. 85—Terminal genital organs of g. dactylopagri. Ventral view. Fig. 86—Cardicola coridodacis from Coridodax pullus. Ventral view. Fig. 87—Posterior end of C. coridodacis. Dorsal view. Fig. 88—Cardicola whitteni from Dactylopagrus macropterus. Ventral view. Fig. 89—Posterior end of C. whitteni. Ventral view.

Holotype: U.S. Nat. Mus. Helminth. Collection No. 49152. Description (based on three specimens): Length 2·128 to 2·168 mm.; width 0·331 to 0·385 mm. Anterior end pointed, often bent ventrally; posterior end subtriangular. Body spination consists of short transverse rows of spines, rows extending ventrally from lateral edges inward 25 to 42μ; rows about 5μ apart. Near midbody the more median spines begin to disappear. No suckers present. Mouth very minute at or near anterior end. Oesophagus at first a very fine tube, gradually enlarging, 0.732 to 0.809 mm. Caeca with short lateral bulges; anterior caeca 0·231 to 0·262 mm. or about ⅓ length of oesophagus; posterior caeca 0·716 to 1.108 mm. ending opposite anterior half of ovary. Testis single, without evident perforations, with slightly irregular but definite outline, filling intercaecal space between ovary and bifurcation. Vas deferens extends directly backward, ventral to ovary; near posterior end of body it enlarges to form an elongate thin-walled seminal vesicle which bends to the left and opens through a dorsal pore near left edge of body. A very short terminal portion of the duct is somewhat narrowed and may represent a rudimentary non-muscular cirrus. Ovary compact, not bilobed but more or less subtriangular. The oviduct leads directly backward from the dorsal posterior tip of the ovary; it is a narrow, straight tube 0.107 to 0.154 mm. long before joining a small ovoid region probably the ootype (Fig. 87). Mehlis' gland weakly developed. Another straight tube seeming to arise from the posterior end of the ovary ventrally is probably the yolk duct; it leads to near the ovoid region of the oviduct but its exact point of entry was not determined. Sperm cells were seen in the basal portion of the uterus. The uterus continues posteriorly from the oviduct, overlaps the anterior end of the seminal vesicle, then turns abruptly forward becoming sinuous or coiled in very short loops in its ascending limb which reaches to the ovary then turns posteriorly as an almost straight tube to the uterine pore. Uterine pore dorsal, halfway between midline and left edge of body, a little anterior to male pore. Its terminal portion is somewhat refractive as if slightly chitinized and represents the metraterm. Vitellaria very fine, forming an indistinct network between caeca and sides of body, becoming sparse along anterior caeca, extending around posterior ends of caeca but not posterior to ovary. Eggs present in only one specimen although the uterus was developed in the others. Eggs very thin-shelled and of variable shape due to pressure against one another; most normal size about 17 to 19 by 12 to 13μ. Excretory vesicle forking almost at once. Discussion: This species and the one following are clearly congeneric with Cardicola laruei Short, 1953, type of the genus Cardicola Short, 1953. Short also included in the genus C. cardicola (Manter, 1947). The genus Cardicola is very similar to Psettarium Goto and Ozaki, 1930. The differences noted by Short (1953) are not clear cut, and although I once suggested such a genus (Manter, 1947, p. 369), the differences so far noted seem rather inadequate. For example, reticulation of the testis (or clear areas resembling perforations' probably appears in varying degree and may possibly result from aging; the vitellaria are not clearly follicular in species I have seen but appear as small cells in irregular clusters which when separated by fine clear channels (excretory tubules ?) might give an appearance of “tubular acini.” These characters are

based somewhat on interpretations. The more compact ovary of Cardicola is more distinctive. In Psettarium the “ramified” ovary consists of tubes lying close together. C. coridodacis differs from C. cardicola in its compact ovary, small Mehlis' gland, and relatively longer posterior caeca. It differs from C. laruei Short, 1953 in unlobed ovary, longer testis, unequal lengths of posterior and anterior caeca and development of seminal vesicle It differs from Psettarium tropicum in shape of ovary, length of posterior caeca, and location of uterine pore. 66. Cardicola whitteni n. sp. (Figs 88–89) Host. Dactylopagrus macropterus (Forster), tarakihi; gills, probably from blood vessels. Locality: Wellington. Holotype: U.S. Nat. Mus. Helminth. Collection No. 49153. Description (based on two specimens): Length 2.548 to 2.772 mm, width 0.501 mm. Most body spines had been lost. Oesophagus 0.760 to 0.840 mm. or from almost ⅓ to ¼ body length. Anterior caeca very short, 0.125 to 0.154 mm.; posterior caeca not reaching posterior end of testis by about 0.2 mm. Testis single, 0.980 to 1.134 mm. long by 0.207 to 0.217 mm. wide, wholly or chiefly intercaecal, reaching to or almost to intestinal bifurcation, slightly irregular in outline, in one specimen sending a few lateral processes past the caeca; in both specimens widening abruptly at posterior end of caeca. Vas deferens leading directly backward to right of ovary then bending to the right; cirrus sac very delicate, thin-walled; male sex pore lateral or slightly dorsal, 0.246 to 0.269 mm. from posterior end of body. Ovary subtriangular, compact but slightly irregular in shape, immediately posterior to testis, slightly to right of midline Oviduct 0.161 to 0.154 mm. long before entering a spindle-shaped glandular region just posterior to which the vitelline duet enters (Fig. 89). Following this region the oviduct is surrounded by gland cells (Mehlis' gland) and bends forward to become the uterus which extends along the left side of the posterior point of the testis to the level of the anterior edge of the ovary; here it turns directly backward and leads to the uterine pore a little anterior to the male pore, dorsal, in the left half of the body. No evidence of a metraterm was seen. Eggs very thin-shelled, packed close together in anterior portion of uterus; size, perhaps somewhat distorted by pressures, about 37 by 16 to 20μ Vitellaria fine and diffuse, from near posterior edge of ovary to the nerve ring; anterior limit less definite. This species is named in honour of Lloyd Whitten. parasitologist at the Animal Research Station, Wallaceville. Discussion: This species is most similar to C. coridodacis but differs in the much shorter anterior caeca, shorter posterior caeca, more anterior extent of the uterus, and more anterior male pore It differs from C. cardicola in shape of ovary, relative length of oesophagus, extent of uterus, in shape of cirrus sac, and character of the ootype region As compared with C. laruei, it has very different caecal lengths.

Host-Parasite List Number of hosts examined indicated in parentheses. Agnostomus forsteri Cuv. & Val.; yellow-eyed mullet (1) Tergestia agnostomi Allomycterus jaculiferus (Cuv.); porcupine fish (4) Anguilla dieffenbachii Gray, 1842; long finned eel (4) Coitocaecum anaspidis Stegodexamene anguillae Telogaster opisthorchis Arripis trutta Forster; kahawai (4) Prosorhynchus sp. immature. Telorhynchus arripidis blenny, unidentified sp. (2) Opegaster gobii Caesioperca lepidoptera (Forster); red perch (1) Lecithocladium excisum Callorhynchus milii Bory; elephant fish (16) Macraspis elegans Cantherines scaber (Bloch & Schn.); leather jacket (2) Pseudocreadium monocanthi Caulopsetta scapha (Forster); flounder (8) Derogenes varicus Opegaster caulopsettae Centriscops humerosus (Richardson); bellows fish (7) Coitocaecum tylogonium Pseudopecoelus japonicus Chelidonichthys kumu (Lesson &. Garnot); gurnard (11) Derogenes varicus Helicometra grandora Plagioporus preporatus Stephanostomum australis Chironemus spectabilis (Hutton); red moki Genolinea anura Coelorhynchus australis (Richardson); rat fish (11) Derogenes varicus Dolichoenterum sp. (immature) Gonocerca phycidis Lepidapedon australis Congiopodus leucopaecilus (Richardson) (1) Coridodax pullus (Forster); butterfish (5) Cardicola coridodacis Cyttus australis (Richardson); boar fish (2) Derogenes varicus Plagioporus (Caudotestis) pachysomus Pseudopecoelus hemilobatus Tubulovesicula angusticauda Cyttus novae-zealandiae (Arthur); silver dory (2) Derogenes varicus Dactylopagrus macropterus (Forster); tarakihi (13) Cardicola whitteni Genolinea dactylopagri Plagioporus dactylopagri Eleotris radiata Quoy 4 Gaim; bully (1) Coitocaecum immature. Galaxias attenuatus (Jenyns); minnow (3) Deretrema minutum Genypterus blacodes (Bloch & Schn.); ling (5) Derogenes varicus Lecithochirium genypteri Tricotylodonia genypteri Geotria australis Gray; lamprey (1) Gobiomorphus gobioides (Cuv. & Val.); bully (4) Helicolenus percoides Richardson; sea perch (5) Ectenurus lepidus Helicometra grandora Pseudopecoelus vulgaris Tricotylodonia genypteri Tubulovesicula angusticauda Jordanidia solandri (Cuv. & Val); hake (7) Kathetostoma giganteum Haast; monk fish (4) Alcicornis longicornutus Latridopsis cilians (Forster); moki (4) Genolinea dactylopagri Holoichis pulcher Proctoeces subtenue Tubulovesicula angusticauda Lepidopus caudatus (Euphrasen); frost fish (5) Leptocephalus conger (Linn.); conger eel (3) Brevicreadium congeri Dolichoenterum longissimum Lecithochirium conviva Lecithochirium congeri Lecithochirium flexum Podocotyle caithnessi Tricotyledonia genypteri Tubulovesicula angusticauda Longirostrum platessa (Cuv. & Val.); trevally (2) Lotella rhacinus (Forster); southern hake (3) Neolepidapedon cablei Opecoelus lotellae Sterrhurus lotellae

Macruronus novae-zealandiae (Hector); whiptail (3) Derogenes varicus Gonocerca phycidis Tubulovesicula angusticauda Merluccius gayi (Guichenot); whiting (1) Gonocerca phycidis Tubulovesicula angusticauda Mola mola Linn; sunfish (1) Odhnerium calyptiocotyle Mustelus antarcticus Gunther (2) Narcobatus fairchildi (Hutton) (1) Notothenia macrocephala Gunther; maori chief (1) Choanomyzus tasmaniae Derogenes nototheniae Mitrostoma nototheniae Proenenterum ericotylum Proenenterum isocotylum Pagrosomus auratus (Forster); snapper (2) Lecithocladium magnacetabulum Parapercis colias (Forster); blue cod (4) Gonocerca phycidis Lecithocladium excisum Pancreadium otagoensis Plagioporus (Caudotestis) pachysomus Steringotrema rotundum Pelotretus flavilatus Waite; lemon sole (4) Benthotrema richardsoni Physiculus bachus (Bloch & Schn.); red cod (12) Derogenes varicus Stephanostomum pristis Tubulovesicula angusticauda Plagiogenion rubiginosus Hutton (1) Bivesiculoides otagoensis Polyprion oxygeneios (Bloch & Schn.); gropei (6) Derogenes varicus Neolepidapedon polyprioni Tubulovesicula angusticauda Pseudolabrus celidotus (Forster); spotty (4) Decemtestis pseudolabri Pseudolabrus coccineus (Forster); soldier fish (5) Myzoxenus crowcrofti Plagioporus interruptus Pseudolabrus pittensis Waite; kelp fish (1) Myzoxenus croucrofti Raja nasuta Muller & Henle (2) Ptygonimus megastoma Retropinna retropinna (Richardson); smelt (3) Salmo gairdneri Richardson; rainbow trout (1) Scorpaena cruenta Richardson; scarpee; led rock cod (9) Gonocerca phycidis Derogenes varicus Tubulovesicula angusticauda Seriolella brama (Gunther); warehou (2) Seriola lalandi (Cuv. & Val.); kingfish (1) Lecithocladium seriolella Squalus kirki Phillipps; dog fish (3) Problitrema philippi Syngnathus norae Waite (3) Thyrisites atun (Euphrasen); barracouta (9) Lecithochirium australis Otiotrema thyrsitae Trachurus novae-zealandiae (Richardson); horse mackerel (10) Ectenurus lepidus Lecithochirium genypteri Pseudopecoeloides tenuis Tripterygion sp. (4) Opegaster gobii Tripterygion varicum (Forster) (1) Zeus faber Linn; John Dory (1) Discussion It is obvious that New Zealand fishes harbour a great variety of digenetic trematodes. The collection of 66 species from 58 species of host is a higher percentage than the author found during three summers of collecting at Tortugas, Florida. Furthermore, only a few specimens of most of the species of fishes were examined, a single specimen in the case of 14 species. In fact, this number of species of trematodes is almost as great as is now known from marine fishes of Great Britain where many more collections have been made. About 70 species of digenetic trematodes have been reported from British waters so far as I can compile from Nicoll (1915), Dawes (1947), and others. The known variety of New Zealand trematodes will without doubt be greatly increased when those of warmer waters of Northern New Zealand have been studied.

Thirty-eight, or more than half, of the species in the present collection were considered to be new. This proportion is probably about what could be expected in a region where no extensive collections had been made previously. The 66 species of trematodes were distributed in 16 families. The great majority, however, were in three families: Lepocreadiidae (11 species); Opecoelidae (17 species); and Hemiuridae (17 species). The other 13 families are represented by from one to four species. Considerable host specificity is suggested by the host records. Fifty-six or about 80% of the 66 species were found in only one species of host: seven were found in two species; and only three species (all Hemiuridae) were markedly polyxenous. Derogenes varicus was found in nine host species; Tubulovesicula angusticauda in ten. The most common condition among trematodes of marine fishes is that a given species is limited to one or a few related hosts. As noted at Tortugas, Florida (Manter, 1947, p. 380), the specificity is at or near the generic level of hosts. Trematodes of birds and mammals are likely to show much less host specificity. At the same time, there are a few species (some hemiurids in particular) commonly found mature in a variety of hosts. It seems likely that at least some of these cases result from progenetic larvae in the intermediate host. Specimens containing eggs would then be found in any host that had recently ingested the intermediate host. Derogenes varicus is noted in the northern hemisphere for the great variety of its hosts and it has the same polyxenous nature in New Zealand. A few species of fishes are particularly favourable hosts for trematodes While 35 species of fishes had one or no species of trematode, Leptocephalus conger had eight; and Helicolenus percoides, Notothenia macrocephala, and Parapercis colias, each had five. One host, Notothenia macrocephala, belongs to a distinctive South Pacifie family. Its five trematodes were all new species and included two new genera. Generally speaking, the same species of host in widely separated localities may or may not have the same parasites. An oceanic fish such as Mola mola has had reported from it much the same parasites in various parts of the world. The conger eel seems to be a favourable host for trematodes wherever it has been examined. However, in European waters its list of 13 species of Digenea contains only one species, Lecithochirium conviva, which I collected from it in New Zealand (and this species, itself, is of somewhat uncertain status) Derogenes varicus will doubtless be found in it in New Zealand, but in general its trematodes are different in the two localities. Eight trematodes from either Conger myriaster or C. nystromi are known in Japan and all of these except Dolichoenterum longissimum are different from those of New Zealand. Four species of trematodes were found in Chelidonichthys kumu, including Plaqioporus preporatus. Yamaguti (1934) reports one trematode. Plagioporus lobatus, from this same species of host in Japan. Trematodes of the conger eel. Leptocephalus conger, are mostly different in the northern and southern hemispheres Thus, no light is shed on the origin and migrations of this fish except that its method of spread was such as to prevent transfer of its trematodes. It might be noted, too. that congers in Japan (Conger myriaster and C. nystromi) have eight species of trematodes which are mostly different from those in conger eels both in the North Atlantic and South Pacific.

However, the conger eel is not bipolar but almost cosmopolitan and it occurs in warm seas (and not below 100 fathoms). As trematodes of marine fishes become better known a comparison of faunas in different regions becomes more interesting and significant. Frequently trematode species have a distribution greater than that of any of then hosts. The distribution of Derogenes various has been noted above (p.). This trematode is extremely polyxenous, and is one of the most widely distributed animals in the world. It appears to be common in deepsea fishes even in the Gulf of Mexico and is surely common in many fishes of the cold North Atlantic, North and South Pacific waters. Yet it is conspicuously absent in fishes of warm seas. In spite of the preliminary nature of the present study, it is of interest to note the affinities of the New Zealand trematodes so far as they are known. Of the 28 species identified as already named: 3 are known only from New Zealand. Of the 25 species reported elsewhere. 17 are known from either the North Atlantic or North Pacific, 11 are known from the North Atlantic, 9 are known from the North Atlantic only, 9 are known from the North Pacific, 6 are known from the North Pacific only, 7 are known from Australia or Tasmania, 3 are known from the Celebes. Only one species, Proctoeces subtenue, occurred in shallow water fishes at Tortugas, Florida, but three (Derogenes varicus, Gonocerca phycidis, and Pseudopecoelus vulgaris) are rather common in deepwater fishes there. Crowcroft (1947; 1950) has reported from Tasmania three additional species which occur in the North Atlantic, two of them also in Japan. These are Helicometra fasciata; Derogenes crassus; and Lintonium vibex Therefore, a total of some 20 species of trematodes have now been reported from the colder waters of both hemispheres These 20 species and their northern distribution are as follows: Derogenes crassus North Atlantic (deepwater) Derogenes varicus North Atlantic; North Pacific Dolichoenterum longissimum Japan Ectenurus lepidus N. Atlantic Genolinea anura N. Pacific Gonocerca phycidis N. Atlantic Helicometra fasciata N. Atlantic; N. Pacific Lecithocladium excisum N. Atlantic; N. Pacific; Mediterr. Lecithocladium magnacetabulum N. Pacific Lecithochirium conviva Mediterranean Lintonium vibex N. Atlantic; N. Pacific Macraspis elegans N. Atlantic Odhnerium, calyptrocotyle N. Atlantic; N. Pacific Proctoeces subtenue Bermuda; Tortugas; Red Sea Pseudocreadium monacanthi N. Pacific Pseudopecoeloides tenuis Japan; Celebes Pseudopecoelus japonicus Japan

Pseudopecoelus vulgaris N. Atlantic (deepwater) Ptychogonimus megastoma N. Atlantic Stephanostomum pristis N. Atlantic Eleven, or 55%, of these species are Hemiuridae, compared with about 25% hemiurids in the entire New Zealand collection. Only a very few of the 20 species (Proctoeces subtenue, Pseudopecoeloides tenuis, and probably Odhnerium calyptrocotyle) extend into warm seas. Thus trematodes, even although incompletely known, show a rather strong “bipolar” trend. Ekman (1953, pp. 252–263) notes that bipolarity more often involves genera or twin-species rather than species. He mentions 8 or 9 species of Radiolaria, 16 species of Polychaeta, 4 species of fishes. New Zealand trematodes appear to have greater affinities to trematodes of the northern hemisphere than do the fishes in which they live. Two chief theories have been proposed to explain “bipolar” species; (1) an actual continuity by way of the deep sea; and (2) a former surface continuity through the tropics during glacial periods when these waters were cooler than at present. At the present time, the data furnished by trematodes could support either or both theories. However, the preponderance of North Atlantic species and the known occurrence of four species in deepwater of warm seas suggest a deepwater continuity. The author believes that the zoogeography of trematodes of marine fishes will become a subject of increasing interest. One suggestion which might result in some help to future investigators is that not only the types of new species be deposited in museums but also specimens of identified species. The latter will then be available for confirmation or restudy by others. Summary Sixty-six species of digenetic trematodes are recorded from 58 species of New Zealand fishes. Such a collection, actually not much more than a sampling, suggests that the trematode fauna of New Zealand is unusually rich. Only about 70 species are known from British waters where they have been studied for many years. Thirty-eight new species and five new genera from New Zealand (about 57% of the total species collected) are named. Ten previously named species are reduced to synonymy and 9 new names are proposed as new combinations. Almost all the previously named species represent new host and geographical records. Keys are given to species of seven genera (Decemtestis; Genolinea: Opecoelus : Plagioporus; Pseudopecoelus; Tergestia; and Tubulovesicula.) A host-parasite list is given. The new genera named are: Neolepidapedon (Lepocreadiidae) Proenenterun (Lepocreadiidae) Pancreadium (Lepocreadiidae) Pachycreadium (Opecoelidae) (not in New Zealand) Brevicreadium (Opecoelidae) Mitrostoma (Hemiuridae)

The new species named are: Alcicornis longicornutus (Bucephalidae) Lepidapedon congeri (Lepocreadiidae) Neolepidapedon polyprioni (") L. australis (") Neolepidapedon cablei (") Proenenterum isocotylum (") P. ericotylum (") Holorchis pulcher (") Myzoxenus crowcrofti (") Pancreadium otagoensis (") Stephanostomum australis (Acanthocolpidae) Opecoelus lotellae (Opecoelidae) Opegaster caulopsettae (") Pseudopecoelus hemilobatus (") Plagioporus preporatus (") P. dactylopagri (") P. interruptus (") P. pachysomus (") Podocotyle caithnessi (") Helicometra grandora (") Coitocaecum tylogonium (") Decemtestis pseudolabri (") Brevicreadium congeri (") Benthotrema richardsoni (Fellodistomatidae) Tergestia agnostomi (") Steringotrema rotundum (") Deretrema minutum (Zoogonidae) Bivesiculoides otagoensis (Bivesiculidae) Lecithochirium genypteri (Hemiuridae) L. flexum (") L. australis (") Lecithocladium seriolellae (") Sterrhurus lotellae (") Derogenes nototheniae (") Mitrostoma nototheniae (") Genolinea dactylopagri (") Cardicola coridodacis (Aporocotylidae) C. whitteni (") New combinations used are : Deretrema messjatzevi (Szidat & Hani, 1951); synonym: Steganoderma messjatzevi Szidat & Hani, 1951. Macraspis cristata (Faust & Tang, 1936); synonym: Stichocotyle cristata Faust & Tang, 1936. Neolepidapedon hoplognathi (Yamaguti, 1938); synonym: Lepidapedon hoplognathi Yamaguti, 1938. Neolepidapedon sebastisci (Yamaguti, 1938); synonym: Lepidapedon sebastisci Yamaguti, 1938.

Opecoelus acutus (Manter, 1940); synonym: Opegaster acutus Manter, 1940. Opecoelus pentedactylus (Manter, 1940); synonym: Opegaster pentedactyla Manter, 1940. Pachycreadium gastrocotylum (Manter, 1940); synonym: Plagioporus gastrocotylus Manter, 1940. Pachycreadium crassigulum (Linton, 1910), synonym: Plagioporus crassigulus (Linton, 1910) Price, 1934. Parahemiurus oatesi (Leiper & Atkinson, 1914); synonym: Hemiurus oatesi Leiper & Atkinson, 1914. The following new synonymies, in addition to those resulting from new combinations, are proposed : Genolinea robusta Lloyd, 1938; synonym of G. laticauda Manter, 1925: Lecithocladium pagrosomi Yamaguti, 1934; synonym of L. magnacetabulum Yamaguti, 1934. Lecithocladium longicaudum Tseng, 1935; synonym of Stomachicola muraenesocis Yamaguti, 1934. Opecoelus mutu Yamaguti, 1940; synonym of O. lobatus Ozaki, 1925. Plagioporus varius (Nicoll, 1910) Price, 1934, synonym of P. alacer (Looss. 1901) Price, 1934. “Syncoelium filiferum (Sars)” of Lloyd & Guberlet, 1936; synonym of S. katuwo Yamaguti, 1938. Tubulovesicula californica Park, 1936; synonym of T. spari Yamaguti, 1934. Tubulovesicula muraenesocis Yamaguti, 1934; synonym of T. spari Yamaguti. 1934. Tubulovesicula pseudorhombi Yamaguti, 1934; synonym of T. spari Yamaguti, 1934. Tubulovesicula madurensis Nigrelli. 1940; synonym of T. lindbergi (Layman, 1930) Yamaguti, 1934. Tubulovesicula nanaimoensis (McFarlane, 1935) Manter, 1947, synonym of T. lindbergi (Layman, 1930) Yamaguti 1934. A tendency toward host specificity is seen in that 56 species, or about 80% of the total, were collected from a single species of host, and only 3 species, all Hemiuridae and probably progenetic, were found in 5 or more species of host. One host, Notothenia macrocephala, belongs to a distinctive South Pacific family. Four of its five trematodes were new species and included two new genera. Some affinities are noted to trematodes of the Northern Hemisphere. It seems evident that the Trematoda will eventually reveal a relatively large number of “bipolar species.” Of the 25 species previously known outside of New Zealand: 17 species occur either in the North Atlantic or North Pacific; 11 species in the North Atlantic (9 being known only from there—including one Mediterranean species); 9 in the North Pacific (6 being known only from there); 7 in Australia or Tasmania; 3 in the Celebes Only 1 species occurred also in the warm Atlantic (Tortugas and Bermuda), but 3 species occur in deepwater fishes at Tortugas, Florida (a fourth species is known from Tasmania and deep-water Tortugas). Including Tasmanian records, 20 species of trematodes are now known from the colder waters of both hemispheres.

Explanation Of Plates All figures are original and drawn with the aid of a camera lucida. The projected scale has its value indicated in mms. in individual figures. Abbreviations are as follows:— a.—anus. ac.—acetabulum. c.—cirrus. ce.—caecum. cm.—circular muscles. cs.—cirrus sac. e.—egg. ep.—excretory pore. ess—oesophageal sac. esv.—external seminal vesicle. ev.— ejaculatory vesicle. ex.—excretory vesicle. ga.—genital atrium. gp.—genital pore. gs.—genital sinus. isv.—internal seminal vesicle. lp.—lateral papilla. mep.—median papilla. mg.—Mehlis′ gland. mp.—male pore. mt.—metraterm. od.—oviduct. ov.—ovary. pa.—preacetabular pit. pg.—prostate gland. ph.—pharynx. pl.—preoral fold. po.—preoral lobe. pp.—pars prostatica. prv.—prostatic vesicle. rh.—rhynchus. sr.—seminal receptacle. ss.—sinus sac. sv.—seminal vesicle. svg.—seminal vesicle glands. t.—testis. te.—tentacle. ut.—uterus. vt.—vitellaria. yd.—yolk duct. References Caballero, Eduardo C. y 1952. Revision de los geneios, y especies que integran la Familia Acanthocolpidae Luhe, 1900. Rev. Med. Vet. y Parasit. 11, (1 & 2), I-XIV. 1–230 Chauhan, B. S.1945. Trematodes from Indian Manne Fishes. Part IV. On Some Trematodes of the Family Hemiuridae Lühe. 1901, with Description of Six New Forms Proc. Indian Acad Sci. 21. 160–173. Crowcroft, P. W. 1945. New Trematodes from Tasmanian Fishes. Pap. Proc. Roy. Soc. Tasm. 1944 (1945). 61–69. — 1946. A Description of Sterrhurus macrorchis n.sp. with Notes on the Taxonomy of the Genus Sterrhurus Looss (Trematoda-Hemiuridae). Pap. Proc. Roy. Soc. Tasm. 1945, 39–47, 2 pls. — 1947 Some Digenetic Trematodes from Fishes of Shallow Tasmaman Waters. Pap. Proc. Roy. Soc. Tasm. 1946, 1–25. — 1947a. The Anatomy of Two New Digenetic Trematodes from Tasmanian Food Fishes. Proc. Linn. Soc. N.S. Wales 71, 108–118. — 1948. A New Digenetic Trematode from the Barracouta (Syncoehidae-Digenea). Pap. Proc. Roy. Soc. Tasm. 1947, 49–57. — 1950. Note on Lintonium vibex (Linton. 1899) (Digenea-Trematoda). Parasit. 40, 316–321. Dawes, Ben. 1946. The Trematoda. Cambridge Univ. Press — 1947. The Trematoda of British Fishes. Ray Soc. London. Dollfus Robert Ph. 1935. Sur Quelques Parasites de Pòissons Récoltés à Castiglione (Algérie). Bull Trav. Sta Aquicul. Peche Castiglione. 1933, (2), 199–279. — 1946. Sur un Distome Parasite de Mullus surmuletus L. et. Peut-êtie Attribuable au Genie Holorchis M. Stossich 1900 (Trematoda) . Bull. Inst. Océan 43, (896), 1–7. — 1952. Miscellanea Helminthologica Maroccana. IV. Affimtés Naturelles de Pseudochetosoma salmonuola R. Ph. Dollfus 1951 (Famille Steganodermatidae Nov.).— Emendation de la Superfamille Haploporoidea W. Nicoll, 1935 Arch. Inst. Pasteur Maroc. 4, (5), 369–386.

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