Anterior End Of Body Research Articles

10.1007/s11474-008-1013-1

Specialized dispersive juveniles of the nematode Bursaphelenchus mucronatus (J4d) were obtained from adults of the black fir sawyer Monochamus urussovi. Judging by the structure of their genital primordium and the primordia of copulatory organs, they correspond to the 4th stage juveniles of the propagation generation (J4), which feed as mycophages and parasites in the conifer wood tissues. The dispersive juveniles differ from those of the propagation generation in such characters as reduction of the stylet, inner cephalic framework, and parts of the pharynx (the median bulb and the pharyngeal gland lobe), a sharply conical tail, and the presence of unicellular glands at the anterior body end. Among entomophilic juveniles, the prospective males and females can be distinguished by the structure of their genital primordium and the primordia of copulatory organs.

First description of the male of Philometra filiformis (Nematoda: Philometridae), a gonad-infecting parasite of the marine fish Pagellus erythrinus (Sparidae) in Mediterranean

The male of the gonad-infecting nematode Philometra filiformis (Stossich, 1896) (Philometridae) is for the first time described, based on specimens from the ovary of the marine fish Pagellus erythrinus (Linnaeus) from the Tyrrhenian Sea off Sicily, Italy. It is mainly characterized by the testis extending anteriorly nearly to the anterior end of body, the oesophagus without a usual anterior inflation, the absence of a dorsal barb or distinct transverse lamellae on the tip of the gubernaculum, the measurements of the spicules and the gubernaculum, and a fairly long body.

Surface morphology of Nicolla skrjabini (Trematoda: Opecoelidae), a common parasite of European freshwater fishes, as revealed by SEM

Scanning electron examination of trematode specimens belonging to Nicolla skrjabini (Iwanitzky 1928), collected from brown trout Salmo trutta fario L. in the Czech Republic, made it possible to study their surface morphology including details not described previously. The tegument bears numerous characteristic papillae mainly around and inside the suckers and around the genital pore and minute sensory organs near the anterior body end. Surface morphology may prove to be useful in distinguishing Nicolla spp.

Morphometric characteristics of first stage Elaphostrongylus cervi (Nematoda: Protostrongylidae) larvae from Bulgaria

A description of the morphology of first stage Elaphostrongylus cervi (Nematoda: Protostrongylidae) larvae on materials from Bulgaria is presented. The larvae were obtained from a red deer (Cervus elaphus L.) from the wildlife-breeding station “Vitinya” in the Balkan Mountains. The metric results about the larvae in micrometers are as follows: body length −423 (377–473), maximum body width −20 (18–24), esophagus length −193 (172–217), distance from the anterior body end to the excretory pore −110 (85–134), distance from the anterior body end to the genital premordium −281 (218–324), distance from the anus to the tail tip −37 (32–42), and tail length −11 (10–14). The present data were compared with previous reports on the same species in West and Central Europe. This is the first morphometric description of first stage E. cervi larvae from Bulgaria and Southeast Europe.

Entomophilic juveniles of the nematode Bursaphelenchus mucronatus (Nematoda, Aphelenchida, Parasitaphelenchidae) obtained from the cerambycid vector Monochamus urussovi (Coleoptera, Cerambycidae) under experimental conditions

Specialized dispersive juveniles of the nematode Bursaphelenchus mucronatus (J4d) were obtained from adults of the black fir sawyer Monochamus urussovi. Judging by the structure of their genital primordium and the primordia of copulatory organs, they correspond to the 4th stage juveniles of the propagation generation (J4), which feed as mycophages and parasites in the conifer wood tissues. The dispersive juveniles differ from those of the propagation generation in such characters as reduction of the stylet, inner cephalic framework, and parts of the pharynx (the median bulb and the pharyngeal gland lobe), a sharply conical tail, and the presence of unicellular glands at the anterior body end. Among entomophilic juveniles, the prospective males and females can be distinguished by the structure of their genital primordium and the primordia of copulatory organs.

Specific features of eye regeneration in multiocular planarians Polycelis tenuis

Regeneration and negative phototaxis were studied in planarians Polycelis tenuis, in which the anterior body end is fringed with many eyes. Comparative data for the same indices are given for binocular planarians Girardia tigrina. Multiple eyes regenerated gradually with a decrease in the rate of regeneration and independently from the rate of restoration of the anterior body end, where they are located. Negative phototaxis was restored independently from the total amount of regenerated eyes. It was unstable in both planarian species.

DESCRIPTION OF A NEW ASCARID SPECIES IN ELASMOBRANCHS FROM TAIWAN STRAIT

A new ascarid of elasmobranchs, Terranova amoyensis sp. n., is described from the intestine of the red stringray, Dasyatis akajei (Müller and Henle), from Taiwan Strait. This is the second report from this genus with a gubernaculum in fish. The new species differs from its congeners mainly in the following combination of characters: the 3 lips are unequal in size and different in shape, i.e., the subventral lips are asymmetric bilaterally and larger than the dorsal lip; the latter lip is bilaterally symmetrical. The ventriculus is spherical, and the cecum is short relative to the esophagus. Spicules are unequal in size, 1.48 mm long for the right spicule and 1.34 mm for the left spicule, or 4.3 and 3.9% of body length, respectively. Nineteen pairs of caudal sessile papillae (excluding phasmids) are present, of which 13 pairs are precloacal; pairs 14 and 15 lie close together on either side of the cloaca, composing ad-cloacal papillae (the pair near the tail end are twins). The remaining 4 pairs of postcloacal papillae form a group near the tail tip (pair 18 also twins and near the phasmids). The gubernaculum is I-shaped. The excretory pore is located on top of a coniform prominence whose location is just behind or between the bases of the 2 subventral lips. The vulva is prominent at one-third of the anterior part of the body; the distance from the vulva opening to the anterior body end is 17.4 mm (13.61-21.41), 26.8% (25.14-28.93%) of the body length.

A new cercaria and metacercaria of Acanthoparyphium (Echinostomatidae) found in an intertidal snail Zeacumantus subcarinatus (Batillaridae) from New Zealand

A new 23-collar-spined cercaria and metacercaria are described from intertidal molluscs of the coast of New Zealand. The new cercaria found emerging from the mud snails Zeacumantus subcarinatus (Sowerby) (Prosobranchia: Batillariidae) is characterized mainly by the number and arrangement of the cephalic glands, the size of the suckers, and the size and number of the collar spines. The cercaria encysts in the cockle Austrovenus stutchburyi (Wood) (Bivalvia: Veneridae) which lives in sympatry with the first intermediate host throughout New Zealand. Laboratory infections of cockles by cercariae from naturally infected snails resulted in metacercariae identical to those found in naturally infected cockles. The main features of the cercaria and metacercaria are the presence of a reniform collar with 23 spines, two pairs of small cephalic glands at the oral sucker level, another two pairs of much longer ones posterior to the pharynx, and the excretory vesicle Y-shaped with the main collecting canals extending to the anterior level of the ventral sucker. Each of the main collecting canals had 10–11 pairs of bilateral diverticula between the anterior edge of the ventral sucker and anterior body end. A brief discussion of its possible life cycle and ecology is also provided.

Lopholeucaspis japonica

<i>Lopholeucaspis japonica</i>

Observations on a cucullanid nematode of marine fishes from Taiwan Strait, Dichelyne (Cucullanellus) jialaris n. sp.

During a helminthological examination of marine fishes from south of the Minnan-Taiwan Bank Fishing Ground, Taiwan Strait, Fujian, China, a new cucullanid nematode, Dichelyne (Cucullanellus) jialaris n. sp., was removed from the intestine of the red seabream, Pagrus major (Temminck & Schlegel, 1834). The new species differs from its congeners mainly in the following characters: body size medium but with relative long spicules of 1.01 mm (0.97-1.06) in length or 20.0% (18.21-21.8%) of the body length; proximal end of spicules somewhat expanded and distal end rounded; gubernaculum I-shaped, slightly narrow in the middle part, both ends rounded; both anterior and posterior cloaca lips round or oval, prominent and unequal in size. The anterior cloaca lip is at least 2 times larger than the posterior one. There is a conspicuous papilliform structure within the central of anterior and posterior cloacal lip. Vulva of female is not prominent, slightly postequatorial; distance from vulva to anterior end of body is 4.3 (3.0-5.5) mm or 58.0% (54.0-62.0%) of the body length. Considering the result of comparing the structure of so-called unpaired median papilla with the 10 pairs of caudal petiolated papillae in the body of the same individual. the papilliform structures are just a backstop for the cloacal lips, this new species represents the first record of a nematode of the Dichelyne, subgenus Cucullanellus in marine fishes of China Sea.

Plesioungella kathleenae gen. n. et sp. n. (Nematoda: Drilonematoidea) from the Australian endemic megascoiecid earthworm Fletcherodrilus unicus (Fletcher, 1889)

Plesioungella kathleenae gen. n. et sp. n. is described from the coelom of the earthworm Fletcherodrilus unicus (Fletcher, 1889), collected in New South Wales. It represents the first nematode of the superfamily Drilonematoidea described from Australia. P. kathleenae gen. n. et sp. n. is characterised by the presence of two thin hooks on the anterior body end, large circular suckers on the tail, and small spines on the eggshell. The male of P. kathleenae gen. n. et sp. n. differs from all other ungellids by the two rows of subventral papillae on the tail and the unusual spicula with ventro‐lateral pieces. Juveniles and a single female of an undescribed thelastomatid nematode were also found in the same earthworm host.

Epidermis and sensory receptors of Temnocephala minor (Plathelminthes, Rhabdocoela, Temnocephalida): an electron microscopic study

The epidermis, rhabditic glands and receptors of the commensal flatworm Temnocephala minor are described using electron microscopic techniques. The epidermis is syncytial and non-ciliated at the anterior body end; it bears folds, microvilli and other structures which differ according to the body side. The nuclei are located intraepithelially and distally from the basal membrane. Long cilia occur at the posterior end anteriorly from the sucker. All receptor structures described belong to a single morphological type and stand in groups arising from epidermal pits. On the tentacles these groups are regularly distributed. Each receptor has a single cilium and a long rootlet. More than 15 000 receptors of this type have been estimated to occur on the surface of a single medium-sized specimen of T. minor. Although the total number of receptor structures appears very high, the number of different receptor types is extremely low in comparison to other taxa of flatworms.

Morphological Observation of Toxocara vitulorum Found in Japanese Calves.

Between 1982 and 1988, ascarid nematodes were found in the feces of Japanese calves in Kyushu and Okinawa districts. Seven males and 21 females of the ascarids were observed morphologically for identification of species. Male and female ascarids were 15.64 (14.0-18.0) cm and 25.75 (16.5-34.0) cm in average length, respectively. Eggs were 81.6 microns and 71.8 microns in large and small diameters, respectively. The body of ascarids was translucent and soft. The boundary between the enlabium and prelabium of lip was clearly visible and the esophageal ventriculus was also observed. The vulva was situated at a distance of about 1/7 approximately 1/9 of body length from the anterior end of body. The surface of egg shell was relatively smooth, without rugose albuminous coat. These morphological features coincided with those of Toxocara vitulorum.

Longidorus Elongatus and Closely Related Species in the Netherlands and Lower Saxony (Germany), With the Description of Two New Species, L. Cylindricaudatus and L. Intermedius (Nematoda: Dorylaimida)

Odontostyle length, tail length, body width, and distance of spear guiding ring from anterior end of body are about 15% larger in populations of Longidorus elongatus without males in those with. Two new species, which are very similar to L. elongatus are described. They both differ from the latter species in having longer odontostyles (105-125 μm in L. intermedius n. sp. and 128-140 μm in L. cylindricaudatus n. sp.) and a more rounded anterior end. The body in the anal region is slightly thicker than more anteriorly in L. elongatus but not in L. intermedius and L cylindricaudatus. The anterior lateral pores lie posterior to the spear guiding ring in L. elongatus, slightly anterior to the spear guiding ring in L. intermedius and at two thirds of the distance from anterior end to spear guiding ring in L. cylindricaudatus.

Morphology and Taxonomy of Two New Otoplanids (Turbellaria, Proseriata) from the Ligurian Sea

Two new species of Otoplanidae belonging to the subfamily Parotoplaninae are described: Parotoplana macrostyla sp.n. and P. uncinate sp.n. In both species the anterior body end bears a swelling. The rhabdites are grouped into bundles of several elements (up to 20 or more). The caudal plate is fan‐shaped. The cuticular apparatus has a stylet and two types of spines. The germovitelloducts do not form the common duct and the bursa stalk has a peculiar structural pattern.

Platyhelminths of Nebraska Turtles with Descriptions of Two New Species of Spirorchiids (Trematoda: Spirorchiidae)

Twenty-one species of platyhelminth parasites are reported from 8 species of turtles collected in Nebraska. Two species of spirorchiids are reported as new. Vasotrema brevitestis sp. n. from Trionyx muticus and T. spiniferus differs from V. amydae Stunkard, 1926, in possessing a relatively shorter, more compact testis, postcecal length equal to one-fifth the body length, a cirrus sac which does not extend to the opposite cecum, and vitellaria composed of discrete follicles more restricted in distribution. Hapalorhynchus foliorchis sp. n. from Chelydra serpentina differs from H. gracilis Stunkard, 1922, in possessing a narrower oral sucker and larger acetabulum, a prominent esophageal constriction, smaller ovary and larger, irregular testes, postcecal space equal to one-sixth the body length, and ventrally oriented uterus. Five other species, Allassostomoides chelydrae, Diarmastorchis blandingi, Vasotrema amydae, V. attenuatum, and Ophiotaenia testudo, are reported for the first time since their description. Nineteen species are reported from Nebraska for the first time. New host records are Trionyx muticus for Vasotrema attenuatum and V. robustum and Graptemys pseudogeographica (Gray) for Allassostomoides chelydrae. From June 1973 until October 1974, the authors collected 16 species of platyhelminths from 55 turtles representing seven species captured in Nebraska (Table I). The results were combined with unpublished data compiled by H. W. Manter for the period 1947-49, bringing the total to 21 species of worms from eight species of turtles. Two species of spirorchiid trematodes are described as new. Spirorchiids were killed with hot water and immediately transferred to AFA. Other worms were flattened with slight coverslip pressure and fixed with AFA. All were stored in 70% ethanol; stained with Mayer's carmalum, Mayer's hematoxylin, or Delafield's hematoxylin; and mounted in Canada balsam. Figures were drawn with the aid of a camera lucida. All measurements are in microns. Dimensions of organs are stated as length by width. Family Spirorchiidae Stunkard, 1921 Vasotrema brevitestis sp. n. (Fig. 1) Description (measurements based on 20 of 34 specimens): Body spindle-shaped, weakly muscled; length 1,300 (1,246 to 1,428), width 115 (108 to 124). Small spines present on anterior end of body, most conspicuous on oral sucker. Oral sucker subReceived for publication 25 November 1974. * Present address: Gulf Coast Research Laboratory, P.O. Box A. G., Ocean Springs, Mississippi 39564. terminal, oval, diameter 50 (40 to 56); acetabulum at anterior end of second third of body, round, diameter 50 (38 to 52). Esophagus 190 long, with ring of prominent diverticula at beginning of posterior third of esophagus. Intestinal bifurcation preacetabular, ceca relatively long; postcecal space one-fifth body length. Testis relatively short, compact, exhibiting some degree of torsion; intercecal at mid-hindbody; 260 (231 to 310) by 90 (70 to 100); ratio of testis length to body length 1:5. Vas deferens straight, passing lateral or dorsal to ovary. Seminal vesicle external, saccular, connected to cirrus sac by short duct. Cirrus sac short, diagonal, not extending to opposite cecum, 72 (66 to 78) by 12 (11 to 12); containing pars prostatica and straight cirrus. Genital pore ventral, posterosinistral to acetabulum. Ovary pretesticular, round to slightly irregular, 40 by 38 (34 to 40). Seminal receptacle postovarian, large, filling intercecal space between ovary and testis. Laurer's canal short; Mehlis' gland composed of very small cells. Uterus saccular, preovarian, sinistral, opening at genital pore. Vitelline follicles discrete, 20 to 40 in number, 12 in diameter; most numerous in region of seminal receptacle, extending dorsally from testicular to acetabular region. Single mature egg 20 by 16; single immature egg 36 by 30. Excretory pore terminal, vesicle convoluted in postcecal region. Type host: Trionxy muticus (LeSueur), smooth soft-shelled turtle. Type locality: Missouri River, 1.5 miles south of Blair, Nebraska. Another host and locality: T. spiniferus (LeSueur), spiny soft-shelled turtle, Atkinson State Recreation Area, 0.5 mile west of Atkinson, Nebraska. Type specimens: Holotype and two paratypes

Otodistomum hydrolagi sp. n. (Trematoda: Azygiidae) from the Coelom of the Ratfish, Hydrolagus colliei (Lay and Bennett, 1839)

Otodistomum hydrolagi sp. n. was obtained from the coelom of 2 ratfish, Hydrolagus colliei (Lay and Bennett, 1839), which were dredged from Puget Sound in the vicinity of San Juan Island, Washington. 0. hydrolagi is the third species of the genus known to inhabit the coelom. The new species bears some resemblance to 0. plunketi Fyfe, 1953, and 0. pristiophori (Johnston, 1902) which also inhabit the coelom of their hosts. Two specimens of a new species of the genus Otodistomum Stafford, 1904, were collected from the coelom of two of 44 ratfish, Hydrolagus colliei (Lay and Bennett, 1839), taken by dredge in the vicinity of San Juan Island, Washington. One specimen was prepared as a stained whole mount. The other, a damaged specimen, was used to prepare serial frontal sections. Measurements are in millimeters unless otherwise indicated. Otodistomum hydrolagi sp. n. (Figs. 1-4) Body light green when alive, fusiform, flat, muscular, nonspinous, 25 long by 10 wide. Oral sucker subterminal, round in ventral view with a diameter of 2; ventral sucker located 5 from anterior end of body, round, with a diameter of 3. Pharynx 0.93 long by 0.6 wide; prepharynx and esophagus absent. Intestinal ceca sinuous, irregular in outline, ending blindly at posterior end of body. Cirrus sac anterior to ventral sucker, oval, 1 long by 0.7 wide, contains curved seminal vesicle and looped prostatic duct; prostatic cells inconspicuous, restricted to widened portion of duct; ejaculatory duct sinuous, extending from cirrus sac to tip of fleshy genital cone; cirrus absent. Testes in midbody region, opposite, triangular in ventral view, 0.8 long by 1.1 to 1.4 wide. Vasa efferentia pass dorsal to uterine folds and join short vas deferens near cirrus sac. Ovary immediately pretesticular, median, triangular, 0.7 long by 0.8 wide. Ootype and Mehlis' gland to left of ovary. Oviduct joins ovary on the left, passes obliquely to posterior end of Mehlis' gland, then turns sharply forward to join ootype. Laurer's canal not observed. Right vitelline duct extends around anterior margin of ovary then passes between ovary and oviduct to vitelline reservoir; left vitelline duct passes obliquely forward to vitelline reservoir which joins oviduct before entering Mehlis' gland. Ootype lined Received for publication 9 May 1972. by flat epithelial cells which appear to be ciliated. Vitelline follicles small, abundant, distributed in U-shaped pattern along ceca dorsal to uterine folds and also filling a wide median area posterior to testes. Uterus composed of many transverse folds which fill space between gonads and ventral sucker; metraterm weakly developed, passes ventral to cirrus sac and ejaculatory duct and opens into genital atrium which is located anterior to genital cone. Genital pore ventral to posterior end of pharynx. Eggs oval, dark brown, operculated, thick-shelled, embryonated, 91 to 94 At long by 67 to 69 ,u wide; shell 7 ,u thick. Excretory vesicle Y-shaped, the stem 5 long, arms of vesicle long, sinuous, uneven in thickness, passing around anterior margin of oral sucker where they unite. Host: Ratfish, Hydrolagus colliei (Lay and Bennett, 1839). Habitat: Coelom. Type locality: Vicinity of San Juan Island, Washington. Type specimens: Holotype and serial frontal sections deposited in USNM Helm. Coll. Holotype No. 72266; paratype No. 72267.

New Species of Onchocercidae (Nematoda: Filarioidea) from Pica pica hudsonia (Sabine, 1823)

The following new species of Onchocercidae (Nematoda: Filarioidea) are described from the American black-billed magpie, Pica pica hudsonia (Sabine, 1823): Splendidofilaria picacardina, from the myocardium directly behind the aortic and pulmonary semilunar valves; Splendidofilaria caperata, from the walls of the pulmonary arteries; Chandlerella striatospicula, from the connective tissue around the splenic artery, esophagus, or in the mesenteries; and Eufilaria longicaudata, from the connective tissue around the esophagus. Microfilariae of all species occur in the blood. No species of Onchocercidae have been described from American black-billed magpies, but there are several reports of microfilariae found during surveys for protozoan blood parasites. Coatney and Roudabush (1937) reported microfilariae in magpies during an examination of birds in Nebraska. In a later study of birds in Montana, Coatney and Jellison (1940) noted two types of microfilariae in magpies. Wagner (1947) reported that 17 of 48 magpies examined in eastern Washington had microfilariae. Hagen and Olsen (1957) found that 62 of 200 magpies in northern Colorado had microfilariae. During a recent survey in central Colorado, Stabler (1961) observed microfilariae in as many as 78.5% of the magpies. This report describes the species found in magpies in northern Colorado. MATERIALS AND METHODS The adult nematodes were obtained during the examination of 143 magpies. All measurements were based on 25 nematodes selected at random from specimens fixed in hot 70% alcohol and cleared in glycerin. Microfilariae were identified by dissection of specimens from living female worms. The presence or absence of a sheath was determined by study of live microfilariae with the aid of a phase-contrast microscope. All measurements were based on 25 specimens selected at random from slides stained with hematoxylin and eosin. The slides were prepared from blood obtained from lungs of heavily infected birds. Measurements are in microns unless otherwise indicated. Splendidofilaria picacardina sp. n. (Figs. 1-9) Description Filarioidea; Onchocercidae (Leiper, 1911) Chabaud and Anderson, 1959; Splendidofilariinae Chabaud and Choquet, 1953; Splendidofilaria Skrjabin, 1923. Slender worms with attenuated extremities. Cuticle thin, with minute, regular annulations and transverse striations. Cuticle with transversely elongated bosses irregularly distributed around the body except at the extremities (Figs. 1, 2). Cephalic extremity with four submedian papillae and two minute amphids (Fig. 5). Buccal capsule absent. Excretory pore not seen. Esophagus long, slender, without evidence of muscular or glandular tissue (Fig. 1). Intestine broad. Caudal extremity usually bears small, lateral protuberances (Figs. 8, 9). Male (Figs. 3, 6, 7, 8) Length 15 (11 to 20) mm, width 112 (95 to 130). Nerve ring 92 (85 to 100) from anterior end of body. Esophagus 450 (430 to 485) long, 6 (4 to 10) wide. Cloaca 76 (62 to 89) from posterior end of body. Caudal extremity blunt, with two pairs precloacal papillae and two pairs postcloacal papillae; some have only seven papillae (Figs. 3, 7). Spicules subequal, dissimilar; left 60 (50 to 65) long, terminating in a point; right 46 Received for publication 22 April 1964. * A portion of a dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Zoology, Colorado State University, Fort Collins, Colorado. This work was done while the author was the recipient of a Dow Chemical Research Fellowship from the Dow Chemical Company, Midland, Michigan. t Present address: USDA, ARS, ADP, P.O. Box 518, University Park, New Mexico.

A Redescription of Gigantobilharzia lawayi Brackett, 1942

Specimens of Gigantobilharzia collected from herring and Bonaparte's gulls in Manitoba during their fall migration are considered to be identical with Gigantobilharzia lawayi Brackett, 1942. Since the original description by Brackett is inadequate, being based on incomplete specimens, a redescription is given including measurements of eggs not previously described. Miracidia of the species failed to infect three local snail species: Lymnaea stagnalis, Stagnicola palustris, and Physa gyrina. During the summer of 1962 a survey was made of the schistosome fauna of Manitoba. Prior to this summer six species of avian schistosomes (McLeod, 1936, 1937, 1940) and one species of mammalian schistosome (Farley, 1962) had been recovered in the province. Adult worms belonging to the genus Gigantobilharzia were found in 2 of 7 herring gulls (Larus argentatus) and 6 of 16 Bonaparte's gulls (Larus philadelphia) examined. Based on the number of testes, position and size of the gynecophoric canal, and position of the ovary, the worms seem to be identical with Gigantobilharzia lawayi described originally by Brackett in 1942 from herring and ring-billed gulls (Larus delawarensis) of Michigan, USA. The description of the species by Brackett was inadequate, since examination of the type material revealed that the specimens were incomplete. Brackett also failed to locate any eggs, either in the uterus of the female or in the gut mucosa of the host. For this reason a redescription of the species is given, based on the examination of seven complete males, two complete females, and many fragments of both sexes. Gigantobilharzia lawayi Brackett, 1942 (Figs. 1 to 4) Specific diagnosis: Gigantobilharzia Odhner, 1910. Received for publication 4 February 1963. * Contribution from the Department of Zoology, University of Manitoba, Winnipeg, Canada. This investigation was supported by a Canadian Industries Limited Wildlife Fellowship. Male: Extremely long and thin with a distinct gynecophoric canal. Suckers absent. Body 21.25 to 38.5 mm (avg 28.9) in length by 0.06 to 0.1 mm wide anterior to the gynecophoric canal, 0.15 to 0.22 mm at the canal and 0.1 to 0.15 mm posterior to the canal. Posterior end of the body swollen but not spatulate. Gynecophoric canal with distinct anterior end 0.86 to 1.25 mm (avg 1.06) from the anterior end of body, 1.75 to 2.7 mm (avg 2.16) in length with the posterior part ending obscurely. Floor of canal with numerous (up to 50) thickened bands at right angles to axis of body, sharply defined anteriorly, becoming less pronounced posteriorly. Esophagus 0.3 to 0.44 mm long, paired ceca short, reuniting in region of the anterior part of the seminal vesicle. Common cecum extending to posterior end of body. Testes 345 to 545 (avg 460), extending from the posterior end of the gynecophoric canal to the posterior end of body, tandemly arranged, and reaching a diameter of about 0.09 mm. Seminal vesicle elongate and spiral, lying anterior to gynecophoric canal, and divisible into two portions: the anterior part or external seminal vesicle lying outside the cirrus pouch, and the posterior part or internal seminal vesicle lying enclosed within the cirrus pouch. External seminal vesicle 0.23 to 0.44 mm (avg 0.32) in length, commencing 0.38 to 0.54 mm (avg 0.43) from the anterior end of the body. Internal seminal vesicle 0.2 to 0.38 mm (avg 0.31) in length. Ejaculatory duct opens on papilla at anterior end of the gynecophoric canal. Female: Filamentous worm about 20 mm in length, with a constant width of 0.75 mm. Suckers absent. Esophagus 0.38 to 0.46 mm long; paired ceca reuniting immediately posterior to the seminal receptacle. Ovary coiled, 0.46 to 0.6 mm (avg 0.57) long, commencing 1.45 to 1.9 mm (avg 1.64) from anterior end of body. Seminal receptacle 0.18 to 0.2 mm in length, situated immediately behind the ovary. Oviduct from posterior end of ovary, receives a branch from the seminal receptacle, and immediately turns forward giving off Laurer's canal. Oviduct receives vitelline duct and opens into ootype 0.23 to 0.28 mm in front

Trematodes of Marine Fishes of Mexican Waters IX. Four Gasterostomes from the Pacific Coast

Host: Scomberomorus sierra Jordan and Starks, sierra Location: Intestine. Locality: Zihuatanejo, Guerrero, Pacific Coast of Mexico. Holotype: U. S. Nat. Mus. Helm. Coll. No. 38120. Paratype: Biol. Inst., Univ. of Mexico No. 214-11. Diagnosis (Based on 6 specimens, measurements on 4): Bucephalus: Body 2.08 to 3.42 long by 0.26 to 0.42 wide; elongate, cylindrical, blunt at anterior end, tapering at posterior end and rounded at posterior extremity. Cuticle with small scale-like spines. Anterior sucker 0.22 to 0.28 long by 0.22 to 0.26 wide; with 7 tentacles. Tentacles 1 and 7 ventral, (tentacles numbered from left side to right side of body, see Fig. 2) each with a pair of lateral basal projections; tentacles 2 and 6 dorsal, each with 3 basal projections; tentacles 3 and 5 dorsal, each with one lateral basal projection; tentacle 4 dorsal, with a pair of lateral basal projections. Dorsal tentacles difficult to observe due to their contracted state. Mouth 1.62 to 1.92 from anterior end of body; posterior to mid-body level. Pharynx 0.075 to 0.094 long by 0.078 to 0.1 wide, usually wider than long, between ovary and anterior testis in posterior half of body although in one specimen pharynx touches posterior testis. Intestine 0.31 to 0.414 long by 0.12 to 0.207 wide; anteriorly directed; anterior to ovary close to its anterior border, but may overlap ovary. In one specimen, esophagus measured 0.172. Genital pore subterminal. Cirrus sac. 0.641 to 0.86 long by 0.117 to 0.14 wide, sinistral, reaching anterior edge of anterior testis in contracted specimens and to posterior end of posterior testis in extended specimens. Cirrus sac-length to body-length ratio 1:2.94 to 1: 3.78. Internal seminal vesicle approximately 1/4 length of cirrus sac. Prostate gland cells surround seminal duct. Genital atrium 0.172 to 0.303 long by 0.094 to 0.165 wide; with 3 lobes, middle longest. Ratio of length of genital atrium to total lengths of cirrus sac and genital atrium from 1: 3.74 to 1: 4.37. Testes tandem, in third fourth of body, dextral, postovarian, usually longer than wide. Ovary dextral; close to, or in contact with anterior edge of anterior testis; slightly anterior to or level with pharynx. Vitellaria composed of round follicles; in two lateral rows beginning about 1/3 body length from anterior end; sinistral row with from 12 to 15 follicles, extending to anterior edge of anterior testis; dextral row with from 14 to 20 follicles, extending to mid-ovary. Uterus in short transverse, ascending and descending coils; extending anteriorly past vitellaria. Eggs operculated, thick shelled, embryonated, 22 to 28 microns long by 13 to 17 microns wide. Excretory vesicle extending to near anterior sucker. The name heterotentaculatus indicates the heterogeneous condition of the tentacles.