Dr. Murai Éva szerk.: Parasitologia Hungarica 18. (Budapest, 1985)
time by ODENING (1968) from Ran___tig_r_.m^rjj^ul_psa and the latter one was recovered from ;?i*ÎI a _UH?JÎ2.^ a E!-J? anc ^ J? a L a i^ e ^°tri^°0.^^°4.^ a-'j_- ^he findings of D. mehrai represent new hosts and locality records. Since a great number of specimens were available for study, it was possible to examine the structure of the muscular organs in both species. These examinations revelaed a solid ground for the validity of the species in question and lead to a discovery of the specific traits which can be used in their differentiation. Accordingly, the structure of the pharynx (Subclavatus in D. amphichrus, Fig. 14; and Megalodiscus in D. mehrai, Fig. 15), the position of the genital opening (post-bifurcal in D. amphichrus and bifurcal in D. mehrai ) and the arrangement of the vitelline follicules (discontinous at the middle part of each lateral region in D. a mphichrus and continuous in D. mehrai ) are the most important specific characters. AMPHISTOMES OF MAMMALS Until recently 36 species of amphistomes have been shown to occur in mammals. We have, however, found the following 22 species in the samples available for examination: Homalo- gaster paloniae, Hawkesius hawkesi , Gastrodiscoides hominis , Paramphistomum epiclitum, P. gotoi , P. ichikawai, Calicophoron calicophorum , C. papillosum, C. microbothrioides, Explanatum explanatum , Gigantocotyle formosanum , Orthocoelium dicranocoelium , O. din- niki, O. saccocoelium , 0. scoliocoelium, Gastrothylax crumenifer , Carmyerius bulbosus, C. spatiosus, C. synethes, Fischoederius cobboldi, F. elongatus and F. japonicus. Of the species discovered on the basi« of our examinations Paramphistomum ichikawai, Cal icophoron microbothrioides, Orthocoelium saccocoelium and O. dinniki were described for the first time from Viet Nam, thus represent new locality records. The pouched amphistomes found in Vietnamese ruminants have been described elsewhere (SEY, 1985a). An examination of the surface topography of the species, Gastrodiscoides hominis (Figs 1-3), O. saccocoelium (Figs 4-7), Gastrothylax crumenifer (Figs 8-10) and Carmyerius synethes (Figs 11-12) by scanning microscopy revealed three types of papillae (dome to conical nonciliated papilla, Figs 7,9), crateryform papilla (Figs 11, 12); short and stumpy papilla, sitting on a tegumental elevation (Fig. 5), which are similar to that described previously by EDUARDO (1982) and SEY (1984b). Of the species recorded for the first time in Viet Nam, Paramphistomum ichikawai has a Calicophoron-type of pharynx, an Ichikawai-type of genital opening (Fig. 20) and a Pisumtype of acetabulum (Fig. 21); the same organs in Calicophoron microbothrioides are: Calicophoron with oesophagus having muscular thickening (Fig. 22), Microbothrium (Fig. 23) and Pi sum (Fig. 24); in Orthocoelium saccocoelium: Saccocoelium (Fig. 29), Papillogenitalis (Fig. 30) and Streptocoelium (Figs 27-28), in O. dinniki : Calicophoron with oesophagus having muscular thickening along the posterior half (Fig. 25), Papillogenitalis (Fig. 26) and Streptocoelium . The samples of Hawkesius hawKesi rendered an examination of the structure of the muscular organs possible for the first time for a this species. The pharynx is characterized by the presence of a moderately developed pharyngeal bulb and welt developed secondary pharyngeal sacs. The pharynx itself is poorly developed and similar to that of the Homalogater (SEY, 1984) and Pseudodiscus (NASMARK, 1937) types, but differs from them by having a moderately developed middle circular and well-developed inner longitudinal layers. I regard this as a new type, named Hawkesius (Fig. 16). The genital opening is moderately developed, characterized by the presence of genital papillae, absence of circular musculature and the existence of a definitive fibre layer, deliminating the genital opening from the surrounding tissue, like to genital sucker. There is a short hermaphrodite duct. It represents a new type of genital opening, named Hawkesius (Fig. 17).
