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Imbricata-type cercariae from Hydrobia salsa, a brackish-water, prosobranch snail taken near Woods Hole, Massachusetts, emerge shortly before noon, are photopositive and encyst after swimming for a few minutes to three to four hours. Metacercariae were fed to chicks and domestic ducklings and developed to mature worms after about two weeks in the bursae Fabricii of these birds. Adult and larval stages are described and figured. The worms belong in the family Notocotylidae and are assigned to the genus, Uniserialis Beverley-Burton, 1958. Systematic problems of genera in the family are discussed.

Linton (1910) described Dinurus rubeus n. sp., a digenetic trematode from species of Lycodontis at Tortugas, Florida, and Manter (1931) described a second species, Dinurus magnus, from Synodus foetens at Beaufort, North Carolina. He (1947) transferred both species to the genus Stomachicola Yamaguti, 1934, as Stomachicola rubea and Stomachicola magna. Meanwhile, Linton (1940) described Dinurus pinguis from Menidia menidia at Woods Hole, Massachusetts, and Manter (1947) transferred this species, pinguis, to Tubulovesicula Yamaguti, 1934. Sinclair et al. (1972) in a 2-year study of Stomachicola rubea noted that the worms attain maximum size only in the stomach of "true" definitive hosts, large fishes, and that small fishes, which ingest planktonic invertebrates, serve as "transfer hosts." In these hosts, the parasites may wander about in the tissues, or may be encysted. These authors predicated that T. pinguis is, in such a transfer host, a stage in the life cycle of S. rubea. Stunkard (1973) described the d...

Digenetic trematodes from the white perch, Morone americana, were identified by Linton (1900) as Distomum areolatum Rudolphi, 1809. He (1901) referred specimens from the cunner, Tautogolabrus adspersus, and the winter flounder, Pseudopleuronectes americanus, to the same species. These worms were collected at Woods Hole, Massachusetts. Other specimens were taken from Bairdiella chrysura, Micropogon undulatus, Orthopristis chrysopterus, and Sciaaenops ocellatus at Beaufort, North Carolina. Linton (1940) included all these worms in a new species, Lepocreadium trullaforme. But they are not specifically identical with L. trullaforme and their taxonomic status has been uncertain. The metacercariae of these worms have been known for many years an unencysted distomes in the ctenophores and medusae taken in plankton collections. The discovery of an ophthalmotrichocercous cercaria from Nassarius trivittatus with the same morphology, has led to the completion of the life-cycle and the resolution of the taxonomic sta...

The morphology, composition and distribution of the genus Stephanostomum are considered. Taxonomic uncertainties and difficulties are discussed. It is postulated that the difficulties can be resolved only with knowledge of life-cycles, larval forms, and developmental stages. Previous accounts of life-histories in the genus are reviewed. The cercariae described by Miller and Northup (1926) from Nassa obsoleta at Woods Hole are listed and their life-cycles are traced. Cercaria dipterocerca Miller and Northup, 1926 penetrated and encysted in laboratory-reared specimens of Menidia menidia. They continued their development and the mature metacercariae manifest such precise agreement in number and shape of peristomial spines and in general morphology with juvenile and mature specimens of Stephanostomum dentatum (Linton, 1900) Manter, 1931, that C. dipterocerca may be the larval stage of S. dentatum. Cercaria dipterocerca is very different, however, from the cercariae described by Martin (1939) and Wolfgang (195...

Encysted metacercaniae of Zoogonus are reported from the seaurchin, Psammechinus miliaris, at Wimereux, France. Comparison with descriptions of other larval Stages found at Roscoff and Marseilles indicates that all belong to the same species. Attempts to infect sea-urchins at Woods Hole with the American form of Zoogonus were only partially successful. Bionomic and morphological differences between the European and American representatives of Zoogonus are discussed. It appears probable that they belong to different species.

In one of his last publications, Joseph Leidy (1891) described a larval trematode, Distomum lasium, from the digestive gland and gonad of Ilyanassa obsoleta at Beach Haven, New Jersey. The account, although brief, was sufficiently complete and definitive to permit positive identification of the species. Leidy reported that I. obsoleta was very abundant on the mud flats near Beach Haven and that on dissecting a number he “? foundthat one in five or six was infested with the larval distomas enclosed in sponocysts, often in large numbers, embedded intheliverand associated genitalgland. The larvaealways appeared in the distoma-form and never as a cercaria.― He noted the shape and size of the sporocysts and of the tailless larvae, and for the latter he recorded the size of suckers, form of the excretory bladder, presence of spines on cuticula, and stylet in the dorsal wall of the oral sucker. This Species was reported by Linton (1915) from the same host at Woods Hole, Massachusetts. During the summers of 1909 and 1910 he had examined over one thousand specimens of I. obsolela and a record of his dissections is presented. Apparently unaware of Leidy's earlier paper, Linton gave a description of the sporocyst and the cercariaeum, but did not name the species. A comparison of the descriptions of Leidy and Linton shows substantial agreement and leaves no doubt concerning the identity of the parasites collected in New Jersey and Massachusetts. The account of Linton was confirmed and augmented by Miller and Northup (1926). These authors had likewise overlooked the reportofLeidy and they named the larvaCercariaeumlintoni.In a study of the seasonal infestation of Nassa obsolela with larval trema todes,theyexamined 8,875individuals collected from a limitedareain QuamquissetHarbornearWoods Hole, and found Cercariaeumlintoni

When eggs ofMonieza expansaare fed to galumnid mites, the onchospheres emerge in the intestine and migrate to the body cavity. Here they undergo metamorphosis and develop into cysticercoids. The dissection of mites, at various intervals after exposure, has yielded a successive series of developmental stages. Protocols of the experiments and photographs of living larvae are presented. These results demonstrate that mites serve as intermediate hosts ofMoniezia, and probably also of other anoplocephaline cestodes.

Summary The problem of specific identity in the genus Bertiella is discussed. Three mature cestodes from a monkey, Macacus rhesus, are identified tentatively as Bertiella studeri. The animal probably acquired the infection in India, but had been in Hamburg for at least six months. The worms and eggs are described and life history experiments are reported. Eggs from gravid proglottids were fed to twenty-four species of free-living mites, collected from different locations in the vicinity of Hamburg. Onchospheres and developing larvae were recovered from the body cavity of Notaspis coleoptratus, Scutovertex minutus, Scheloribates laevigatus and Galumna sp. Cysticercoids were removed from S. laevigatus and Galumna sp. They were spherical, to oval, to pyriform, 0.1 to 0.15 mm. in diameter, and provided with small cercomeres. It is clear therefore that Bertiella, like other anoplocephaline cestodes, Moniezia and Cittotaenia, utilizes free-living mites as intermediate hosts.

Linton (1940) described the adult stage of Zoogonoides laevis and distinguished between this species and Z. viviparus (Olsson, 1868) Odhner, 1902, the type and only other known representative of the genus. He found the worms in the intestine of Tautoga onitis and an immature specimen from the round herring, “? Etrumensadina― (= Etrumeus teres) was referred provisionally to Z. laevis. During the summer of 1942, tailless cercariae were found emerging from Columbella (= Mitrella Rizzo) lunata collected in the Woods Hole region. -Their striking resemblance to the cercariae of Zoogonus lasius (Leidy, 1891) Stunkard, 1940 indicated that the two were closely related. Furthermore, their morpho logical agreement with Zoogonoides laevis suggested that they might be larvae of the latter species. Experiments demonstrated the correctness of the hypothesis and the successive stages in the life cycle have been obtained. The cercariae develop in sporocysts in the lymph spaces of C. lunata, penetrate into Nereis virens where they become metacercariae, and sexual maturity is attained in the intestine of T. onitis. The eggs are large, without shells, and contain active, ciliated miracidia when extruded. The larvae hatch in sea water and invade the snails where the asexual generations are produced. The life history was reported in abstract (Stunkard, 1942).

The advantages and difficulties of various methods employed in the study of larval trematodes are discussed. The desirability of using living specimens rather than fixed material and of studying mature, normally emerged cercariae rather than those obtained by crushing the host is noted. Intra-vitam staining with neutral red is recommended to demonstrate the form and reaction of the secretory granules in gland cells. Knowledge of the details of the excretory system is of major importance in both theoretical and experimental work.

Seven species of cercariae and four of metacercariae collected at Roscoff, Finistère, during August, 1931, are described. They have been referred to appropriate systematic groups and wherever possible, probabilities concerning life histories are suggested. Four of the cercariae and two of the metacercariae are recorded as new to science.

1. The life-history of Microphallus similis has been worked out by experimental infection of both intermediate and final hosts.2. Encysted metacercariae from Carcinides maenas developed to sexual maturity in Larus argentatus and Sterna hirundo. Eggs of the parasite developed in these hosts were used to infect Littorina obtusata. Two generations of sporocysts were recovered.3. Littorina saxatilis and Littorina littorea also harbor the asexual generations at Woods Hole, Massachusetts.4. The cercariae are minute, stylet-bearing monostomes and small green crabs, C. maenas, exposed to these cercariae became heavily infected; enormous numbers of larvae entered the tissues and developed into metacercariae identical with those of natural infections. Small crabs, each exposed continuously to the cercariae from six to eight infected snails, died in ten to twenty days and on dissection each yielded thousands of larvae.5. The stages in the life-cycle of the parasite agree with descriptions by European investigators o...

The genus Renicola was erected by Cohn (1904) to contain Monostomum pingue (Mehlis in Creplin, 1846), when he discovered that the species has a distinct acetabulum and could no longer be regarded as a monostome. He studied the original material of Mehlis, from the kidneys of the crested grebe, Podiceps cristatus, in both whole-mount preparations and serial sections. He noted that the worms, although hermaphroditic, live in pairs in expansions of the renal tubules, that there is no copulatory organ, and that the acetabulum is so obscured by eggs in the uterus that it is quite invisible in whole-mount preparations. In this paper he advanced the idea that adhesive organs of trematodes which live in closed cavities do not function actively and accordingly either fail to develop or undergo atrophy and become reduced in size. The second and third species of the genus, Renicola secunda and R. tertia, were described by Skrjabin (1924) from the white pelican, Pelecanus onocrotalus, and from the tern, Sterna fluviatilis, respectively, both taken in Russian Turkestan. The descriptions are brief, listing sizes of body and of eggs, but the figures give other pertinent information. The three species of Renicola were characterized by shape of body, including the degree of posterior extension, the relative length of the digestive ceca, and the location and extent of the vitellaria. However, Skrjabin stated that because of meager material, specific determination was uncertain. Yamaguti (1958) listed Renicola zarudni Skrjabin, 1927, from a pelican taken by the 28th Helminthological Expedition of the U.S.S.R. to Turkestan. However, there is no reference to R. zarudni in Skrjabin, Trematodes of Animals and Man, vol. 1, pp. 261-277 (1947), which deals with the genus Renicola. Odening (1962b) listed R. zarudni as a nomen nudum and the species as identical with R. secunda Skrjabin, 1924. The next species of the genus was described by Witenberg (1929) from Puffinus kuhli, taken by the Sinai Expedition of the Hebraischen Universitaet, Jerusalem, to the Suez. Witenberg noted that the descriptions of the previously named species were so incomplete that determination of new material should be made with caution. To identify the specimens from P. kuhli, they were designated provisionally as a new species, Renicola glandoloba, although Witenberg admitted the possible identity of the previously described species with the new species described by him.

The genus Renicola Cohn, 1904, was based on Monostoma pingue (Mehlis in Creplin, 1846) ; it is cosmopolitan in distribution and species have been found in the kidneys of birds belonging to various families. Cercaria rhodometopa , Perez, 1924, has a similar excretory system and the rhodometopous cercariae have been regarded as renicolid larvae, although attempts at experimental infections have so far proved futile. Cable (1963) reported that certain plagiorchid cercariae are larvae of renicolid species and postulated that species of Renicola may have two types of cercariae, either rhodometopous or plagiorchid larvae. Stunkard (1964) described plagiorchid cercariae from Thais lapiltus and their development in the renal tubules of gulls, Larus argentatus , to adults that were identified as a new species, Renicola thaidus . He noted that these cercariae are similar to others from Littorina spp., viz., Cercaria parvicaudata , Stunkard and Shaw, 1931, and Cercaria roscovita , Stunkard, 1932. Werding (1969) reported that metacercariae of C. roscovita developed in the kidneys of L. argentatus to adults identified as Renicola roscovita (Stunkard, 1932). He suggested the identity of C. roscovita and C. parvicaudata . Robson and Williams (1970) identified cercariae from Littorina littorea as Cercaria A ; the larvae agreed morphologically with C. roscovita , but attempts to infect juvenile L. argentatus , ducklings, chicks and various laboratory mammals failed. Repeated attempts by the writer to infect L. argentatus and other birds with metacercariae of C. parvicauda have given only negative results. The systematic position of the rhodometopodous cercariae is enigmatic, but the inclusion of such morphologically diverse types as the plagiorchid and rhodometopodous cercariae in a single genus controverts ideas of generic unity.

The metacercarial stage of Ascocotyle (Phagicola) diminuta Stunkard and Haviland, 1924 has been found encysted in the gills of Fundulus heteroclitus. Experimental infections of rats, mice, hamsters, Larus argentatus and Nycticorax nycticorax have yielded adult worms and permitted additions and emendations to the description of the parasite.

Metacercariae from Limulus polyphemus developed to sexual maturity in white mice and golden hamsters. The worms are described as a new species, Microphallus limuli. Morphologically they are very similar to M. claviformis (Brandes, 1888), but bionomic features seem to preclude their allocation to that species. The genus Microphallus is discussed, Spelophallus Jagerskiold, 1908 is suppressed as a synonym and S. primus Jagerskiold, 1908, the only known species, is transferred to Microphallus as M. primus (Jagerskiold, 1908). In agreement with Cable and Kuns (1951), the family Maritrematidae Baer, 1943 is not accepted.

The digenetic trematode described by Linton (1900) as Distoma pyriforme has been reported from many hosts and several species have been included in the accounts, with resultant confusion. It was included in the genus Lepocreadium Stossich, 1904 by Linton (1940), but it is not congeneric with L. album (Stossich, 1890), type of the genus. Its life-cycle has been elucidated; Anachis avara is the first intermediate host, where cercariae are produced in rediae. The cercariae are ophthalmotrichocercous, swim actively with the tail in advance. They penetrate but do not encyst in certain hydrozoan and scyphozoan medusae and in the ctenophore, Mnemiopsis leidyi. Developmental and adult stages resulted from ingestion of metaceracariae by the scup, Stenotomus chrysops. Eggs from worms were embryonated; miracidia emerged in 8 to 10 days, penetrated into A. avara, transformed into sporocysts, and produced rediae in 5-6 weeks. Worms recovered from S. chrysops are assigned to a new genus, Neopechona, and redescribed as ...

A chronological account of the genus Azygia discloses discordant observations and divergent opinions. Dawes (1946) recognized only a single species, A. lucii, in Europe. In it he included A. robusta Odhner, 1911, which reaches a length of 47 mm. and Ptychogonimus volgensis von Linstow, 1907, which measures 5 to 6 mm. in length and had been transferred to Azygia as a valid species by Odhner (1911). In America several species have been described, but there is no agreement on the number that are distinct and valid. In fact, there is no adequate information on the extent of variation that occurs in a natural species, and consequently on the features that can be relied on to distinguished between species. This situation is not peculiar to Azygia, but obtains in many genera. It is the natural result of development by members of a parasitic species in different hosts, invertebrate and vertebrate, often of different taxonomic groups, which differ in their nutritional and other physiological conditions, and accord...

The life history of Parorchis avitus has been experimentally traced. The cercariae occur in the marine snails, Urosapinx cinereusand Thais (Purpura) lapilius. Adults have been obtained from the cloaca of the common tern, Sterna hirundo, and the roseate tern, Sterna dougalli, after feeding the young birds with encysted larvae.It has been shown that a specific secondary intermediate host is not essential for the completion of the life history; only a means of transference is necessary.Additional morphological differences between Parorchis avitus and Parorchis acanthus are described.

In a recent publication, Vik (1964) p. 6, observed, “Although the genus Diphyllobolhrium Cobbold, 1858, has been revised several times (Liihe, 1910, Cohn, 1912, Stunkard, 1949, Wardle and McLeod, 1952, and Yamaguti, 1959) since the type species was described by Cobbold in 1858, the systematics of the group are still in a state of confusion and identification is made difficult by discrepancies in original and subsequent descriptions. However, the significant facts here are that Diphyllobothrium species from land mammals and fish-eating birds, those about whose life cycle we know most, do not seem to be especially host specific; and that in tapeworm specimens of the same species—factors such as the age of the worm, age and nutrition of the host, degree of crowding in the intestines, etc., as well as the species of host used, may result in marked differences in appearance.” This appraisal of the situation is modest and conservative.

In a report on the effect of dilution of sea-water on the activity and longevity of certain marine cercariae, Stunkard and Shaw ( 1931 ) described two new species of cercariae. One of them, Cercaria sensifera, was shown by Stunkard and Cable (1932) to be the larval stage of Parorchis avitus Linton, 1914 [ P. acanthus (Nicoll,1906)Nicoll,1907] . Thelifehistoryandadultstagesoftheotherspecies, Cercaria parvicaudata, is yet unknown. The original account of C. parvicaudata was brief, incomplete and in certain respects inaccurate ; further study permits a more adequate description of the species and may aid in the elucidation of the life cycle. Cercaria parvicaudata occurs in Littorina littorea (Linn., 1758) FA©russac, 1822; in L. saxatilis (Olivi, 1792) Johnston, 1841 [ L. rudis (Maton, 1797) Forbes, 18381 ; and in L. obtusata (Linn., 1758) FA©russac, 1822 [ L. palliata (Say, 1822) 1.†So far, the infection has been reported only in the region of Woods Hole, Mass. About one per cent of the individuals of the first two species is infected, but infections in L. obtusata are rare. Shedding of the cercariae is ir regular ; often an infected snail will not shed any cercariae for several days. The larvae may emerge at night or during the day. Multiple infections with Cercaria parvicaudata and other species, viz., cercariae of Cryptocotyle lingua, and with a small undescribed microphallid species, have been found in L. littorea and in L. saxatilis. The cercariae are produced in orange-colored sporocysts, localized usually in a single, oval mass situated between the intestine and the body wall of the snail and about midway between the ends of the visceral portion. The mass may be from 2 to 10 mm. long; when large it causes protrusion of the body wall and is easily recognized by the orange color when the shell of the snail is removed. Occasion ally more than one mass is present and as many as four have been observed. Each mass contains from hundreds to thousands of daughter sporocysts restricted to a circumscribed region; they do not occur in the lymph spaces throughout the body of the snailand are absent from the digestivegland, although cercariaehave been found in the hemocoele when snails were dissected. It is probable that each mass of sporocysts constitutes the progeny of a single miracidium, and when two or more masses are present, which is rare, that multiple infection has occurred. The location of the sporocysts suggests that the snail ingests the embryonated egg of the trematode, that the miracidium emerges in the intestine, migrates through the

A cestode, identified as Bertiella studeri, was obtained after therapy from a 5-year-old boy at Mankato, Minnesota. This case is apparently the first autochthonous infection of man by an anoplocephaline cestode reported in North America. The specimen is described and compared with specimens of B. studeri from a Rhesus monkey in Hamburg, Germany and a cotype of B. mucronata from the Helminthological Collection of the U.S. National Museum. Specificity in the genus Bertiella is discussed. (Author)

The account of Mme. Kulachkova (1954) on the life-history of Paramonostomum alvealtum is confirmed. The asexual generations and larval stages of both Paramonostomum alveatum and Paramonostomum parvum occur in the prosobranchiate snail, Hydrobia salsa, found in brackish-water ponds near Woods Hole Massachusetts. Sexually mature worms have been obtained by feeding metacercariae to day-old chicks and laboratory-reared eider and domestic ducklings. Adult and larval stages of both species are described and figured. Problems of specific identity in the genus Paramonostomum are discussed.

Cercariae from Hydrobia minuta Totten, taken in the Massachusetts area, have been identified as the larvae of Microphallus limuli Stunkard, 1951; The sporocysts and cercariae are described; young Limulus polyphemus were infected; and adults were recovered after feeding the metacercariae to mice. Systematic relations of species in the genus Microphallus are reviewed.

The asexual generations of an echinostome trematode were found in the hemal sinuses of the marine snails, Littorina saxatilis and Littorina obtusata, in the region of Woods Hole, Massachusetts. The cercariae develop in rediae and after emergence encyst in bivalve mollusks. Mytilus edulis and Mya arenaria were employed as experimental hosts. The metacercariae developed to sexual maturity in the intestine of laboratory-reared herring gulls, Larus argentatus, and the worms are described as a new species, Himasthla littorinae. Successive stages in the life cycle are figured. Stunkard (1960) reviewed previous studies on the genus Himasthla Dietz, 1909, con- sidered criteria for specific determination, and discussed the validity of certain described spe- cies. Echinostoma annulatum (Diesing, 1850) Cobbold, 1860, was transferred to Himasthla, and Himasthla tensa Linton, 1940, was sup- pressed as a synonym of Himasthla elongata (Mehlis, 1831) Dietz, 1909. A not fully ma- ture specimen from Nycticorax nycticorax (L.), tentatively assigned to H. elongata, is very similar to Himasthla secunda (Nicoll, 1906) Dietz, 1909. This observation may suggest that H. secunda is a not fully mature form of H. elongata. Metacercariae from the palps and gills of Mya arenaria L., taken in the region of Boothbay Harbor, Maine, developed in the

The acanthocephalan genus, Prosthenorchis, is reviewed. Natural and experimental hosts and pathological effects of infection are cited. The anobiid beetles, Lasioderma serricorne and Stegobium paniceum, proved susceptible to infection and are listed as new intermediate hosts of Prosthenorchis elegans. During the early years of the last century, Johann Natterer made extensive collections in South America and the material was deposited in the Museum of Vienna. Among the helminthic parasites were thorny-headed worms, Acanthocephala, from Cebus sciureus (= Saimiri sciurea)l; Jacchus rosalia (= Leontideus rosalia); Jacchus ursulus (= Saguinus tamarin); and Jacchus (Hapale) chrysoleucos (= Callithrix chrysoleuca). Specimens from Leontideus rosalia were described by Olfers (in Rudolphi, 1819) as Echinorhynchus spirula. Others, from the four hosts listed above, were described by Diesing (1851) as Echinorhynchus elegans. This latter species was reported from Saguinus (Oedipomidas) oedipus by Cobbold (1876).

Some thirty-three species of pseudophyllidean cestodes have been described from seals and sea-lions but the descriptions are so incomplete and imperfect that it is virtually impossible to recognize any of them with certainty. Redescriptions of species, on the basis of incorrectly determined specimens, have undoubtedly added to the confusion. In the absence of information concerning life cycles, consideration must be given to the possibility that representatives of a single species may complete their development in different host species and furthermore that, as a result of development in different hosts, individuals of the same species may manifest differences in size and shape, in rate of growth and sexual maturity, and in extent of development of various tissues and organs. Consequently, specific determination of specimens presents a particularly difficult problem. The pseudophyllidean cestodes of seals and sea-lions have been assigned to nine different genera, but the generic concepts are so indefinite and their limits are so poorly defined that there is no agreement concerning either the number of valid species or the generic groups to which they should be allocated. The uncertainty and confusion regarding the morphology and taxonomy of these cestodes were discussed by many earlier authors and more recently by Mueller (1937) and Wardle, McLeod and Stewart (1947). Most of the species have been referred, at one time or another, to the genus Diphyllobothrium Cobbold, 1858 as emended by Liihe (1910). The genus Diphyllobothrium, as defined by Liihe, is a heterogeneous assemblage and taxonomic revision of these tapeworms was proposed by Mueller (1937) and by Wardle, McLeod and Stewart (1947). The latter authors stated: "It is a cumbersome group of about 70 species-many of them of dubious validity-and comprises forms from toothed-whales, seals, sea-lions, carnivorous land mammals and fisheating birds. Several species have been recorded from humans and one even from a snake. It has always been an unsatisfactory genus to define and analyze, and particularly difficult to evaluate have been the forms from seals and sea-lions that have been recorded by numerous writers." Wardle et al erected a new genus, Cordicephalus, to contain the species found in seals-and sea-lions and recognized four species: Cordicephalus phocarus (Fabricius, 1780) ; C. tectus (Linstow, 1892); C. arctocephalinus (Johnston, 1937) ;and C. quadratus (Linstow, 1892). All other species from seals and sea-lions were regarded as identical with one or other of the four accepted species. The remaining species of Liihe's genus were distributed among six other genera: Diphyllobothrium Cobbold, 1858; Diplogonoporus Loennberg, 1892; Dibothriocephalus Liihe, 1899; Glandicephalus Fuhrmann, 1921 ; Adenocephalus Nybelin, 1931; and Spirometra Mueller, 1937.

The U. S. Fish and Wildlife Service is perturbed because of the reduction in numbers of the soft-shelled clam, Mya arenaria, along the coast of New England (Glude, 1955). The writer is studying the parasites of the clam and of its predators (Stunkard, 1951, 1953, 1957, Stunkard and Uzmann, 1958) in an attempt to discover the causes of the decline and possible biological measures for control of the principal predators, the green and horseshoe crabs, Carcinides maenas and Limulus polyphemus. Mya arenaria harbors the asexual generations of digenetic trematodes, including the sporocysts and cercariae of Cercaria myae Uzmann, 1952. These larvae were shown by Stunkard and Uzmann (1958) to be developmental stages of a species of Gymnophallus, whose sexual generation occurs in shore-birds. The asexual stages invade the digestive and sexual organs of the mollusk, limiting or terminating its reproductive activity. The clams also serve as intermediate hosts of other trematodes and 3 species of metacercariae occur commonly in the gills and palps. The life-cycles and bionomics of these worms are now under investigation. Since the asexual generations of these metacercariae must occur in mollusks which live in the immediate vicinity of the infected clam, an attempt is being made to find and identify them. Furthermore, since the definitive hosts of these metacercariae are animals that feed on M. arenaria, examination of shore-birds has been started. To obtain information on the sexually mature stages, metacercariae have been fed to laboratory-raised birds: chicks, eider ducks, herring gulls and common terns, as well as to mice and hamsters. The clams and other mollusks, the eider ducklings, and a sampling of shore-birds were provided by Walter R. Welch, Chief of Clam Investigations, Boothbay Harbor, Maine, under whose authority the study is conducted. Grateful appreciation is here expressed to him and members of his staff.

A massive infection with what is apparently the same species was discovered in a young male Gorilla gorilla gorilla (Savage and Wyman) which died in New York. At death the animal weighed 30.8 pounds and was probably about two years old. It had been brought by airplane from Africa on February 7, 1949, and although it came from the Congo region the locality where it was taken is uncertain. The animal was ill on arrival and shortly thereafter one of us, (L. J. G.) veterinarian of the New York Zoological Society, was called for medical advice and treatment. Its temperature fluctuated between 99 and 102 degrees F.; there were recurrent intestinal disturbances, anorexia, intermittent diarrhea and constipation. At times there were periods of two to four days in which there were no bowel movements. The fingernails had transverse bands of roughened areas, suggesting previous nutritional deficiencies or febrile conditions. Neither anemia or jaundice was noted. One eyelid was injected with one-tenth cc. of 1 percent P.P.D. tuberculin; there was an immediate reaction. An edematous swelling of the lid completely closed the eye in a few minutes, but totally subsided within five hours. No tubercular lesions were observed at autopsy and the significance of the reaction is obscure. Several fecal examinations were made; hookworm eggs were present in large numbers but no trematode eggs were observed. To remove the hookworms, two treatments with tetrachlorethylene were administered but ova persisted in the stools. After the second treatment, diarrhea developed and the mucus contained large numbers of amoebae. Administration of carbarsone had no apparent effect on the amoebae; the dysentery continued and emetine hydrochloride was given. This treatment also proved ineffective; the stools became bloody and were unformed during the subsequent life of the animal. It failed to give the expected response to medication or to symptomatic and supportive measures. During a six week period it lost about four pounds and died of terminal pneumonia on April 2, 1949. Autopsy of the gorilla was begun within three hours after death. The carcass showed no gross lesions other than early stages of lobar pneumonia, but the hepatic and especially the pancreatic ducts were filled with enormous numbers of small trematodes. Examination of the rectal contents revealed a few trematode eggs, but the number was not at all commensurate with the intensity of the infection. A piece of pancreas about 10 by 10 by 15 mm. was teased to bits in a Petri dish containing Ringer's solution. The worms were fixed and counted; 1028 specimens were present. Pieces of the liver and pancreas were removed, fixed and cut in serial

Cestodes collected by the Plague Mission to Venezuela 1950, which was sponsored by the Pan American Sanitary Bureau, the Venezuelan Government and the Bureau of Medicine and Surgery, U. S. Navy, were submitted to the writer by Doctor Ernst Schwarz, U. S. Naval Medical School, Bethesda, Md., for study and identification. The worms were found in the small intestine of a hystricomorph rodent, Proechimys cayennensis trinitatis (Or. No. 158; male; from Campamento Raphael Rangel, Sierra Maestra, Estado Aragua, Venezuela; altitude 1260 meters; collected by E. Schwarz, J. M. Amberson, H. K. Schwarz, July 27, 1950). Members of the genus Proechimys are found in tropical forest in Central and South America from Nicaragua to southern Brazil. Grateful acknowledgment is made to Doctor Schwarz for the opportunity to study this material. The tapeworms are referable to the genus Raillietina and to the subgenus Raillietina in which the genital pores are unilateral and each egg-capsule contains more than one egg. Specific determination, however, presents a very difficult problem. The genus Raillietina is cosmopolitan in distribution; the worms infect birds and mammals and have been reported repeatedly from man. In a review of the genus, Hughes and Schultz (1942) listed 226 described species and many others have since been added. In human hosts the worms have been found only sporadically, in widely separated localities, and usually in small numbers. Joyeux and Baer (1929) postulated that rare cestodes of man are accidental infections by species naturally parasitic in other animals, especially rodents, which live in the same areas. The first report of human infection by a species of Raillietina was given by Davaine (1870)* who described Taenia madagascariensis from two specimens passed by children living on the Comores islands near Madagascar. Blanchard (1891) transferred the species to the genus Davainea, and Fuhrmann (1920) included it in the new genus Raillietina. This or other closely related species have been reported from man and rats at various places in southern and eastern Asia. Leuckart (1891) reported it from man in Siam and Garrison (1911) from man in the Philippine Islands. The earlier accounts pertained to human infections but, as wild animals were examined for parasites, many species of Raillietina were described from birds and mammals of the Eastern Hemisphere (see Meggitt and Subramanian, 1927). L6pez-Neyra (1930, 1931) suggested that many of the species described from Africa and Asia represent varieties of a single species which infects rodents and occasionally man. Narihara (1935) reported R. miadagascariensis from both men and rats in Formosa, and Miyazaki (1950) found the species in Rattus norvegicus and R. rattus in Japan. Joyeux and Baer (1936) found specimens of

SUMMARY Thousands of free-living mites were collected near Hamburg from areas where wild rabbits were numerous and heavily infected with anoplocephaline cestodes. The mites were dissected and cysticercoids were removed from Scutovertex minutus, Scheloribates laevigatus and Pelops tardus. The larvae were fed to young, domestic rabbits and a cysticercoid froIn S. minutus developed into a sexually mature specimen of Cittotaenia ctenoides. Other mites, collected from areas where they would not be exposed to eggs of anoplocephaline cestodes, were fed eggs of Cittotaenia ctenoides and C. denticulata. Developmental stages of C. ctenoides were recovered from the body cavities of Scutovertex minutus, Galumina obvious, Pelops acromius, Liacarus coracinus, Notaspis coleoptratus, Liebstadia similis, Xenillus tegeocranus, Scheloribates laevigatus, Cepheus cepheiformis, Trichoribates incisellus, and Galumna This content downloaded from 157.55.39.76 on Wed, 20 Apr 2016 06:52:21 UTC All use subject to http://about.jstor.org/terms THE JOURNAL OF PARASITOLOGY nervosus. The larvae attained the cysticercoid stage in the first seven of the species listed and, since development appeared normal in the other mites, it is possible that they might have completed their development if the hosts had lived long enough. Development of C. denticulata was observed in S. minutus, X. tegeocranus, C. cepheiformis, T. incisellus, S. laevigatus, and L. coracinus, although only S. minutus lived long enough in the cultures for cysticercoids to be produced. Infections were obtained only in oribatid mites. None of the rabbits fed cysticercoids from experimentally infected mites gave evidence of infection and it is probable that these larvae were not entirely mature. The developmental stages of C. ctenoides and C. denticulata in the intermediate hosts are described from experimental infections. The development of C. ctenoides, C. denticulata and C. pectinata in the final hosts is described from natural infections. No evidence was found to support the idea that these tapeworms migrate from the intestine to the body cavity of normal, live, rabbits.

The material which forms the basis for this paper consists of two tapeworms from the intestine of the limbless lizard, Anniella pulchra nigra, collected near Castroville, California by Charles M. Miller and sent for identification by Professor Harold Kirby of the University of California. Sincere gratitude is here expressed for the privilege of studying these specimens. The first cestode (Fig. 3) has a scolex and thirty attached segments; the terminal proglottid (Fig. 1) is sexually mature but not gravid. The other worm consists of a scolex and twenty-eight segments, the last not fully mature. In addition, there are seventeen detached proglottids, fragments of the terminal part of a strobila, and probably from the second cestode, since the medially directed terminal portions of the excretory tubes of the first one indicate that it is almost complete. The detached pieces consist of gravid proglottids in which the embryos are uniformly distributed throughout the segments and vary in size from minute morular masses to fully-developed onchospheres in thin-shelled eggs. The specimens were in poor condition and unsuitable for sectioning; consequently only haematoxylin-stained whole mounts were made. Although the amount of material is small for a positive specific determination, the cestodes undoubtedly belong to the genus Oochoristica. Since the species of the genus are not clearly delimited and the amount of normal variation which occurs within a given species is not well established, it is questionable to what extent morphological differences should be considered as merely intra-specific variations. The present specimens, however, show marked differences from all previously described forms and we are unable to assign them to any known species. Accordingly, they are described and listed tentatively as a new species, Oochoristica anniellae.