Dr. Murai Éva - Gubányi András szerk.: Parasitologia Hungarica 28. (Budapest, 1995)

When La Rue (1926) described the genus Diploproctodaeum (on the basis of MacCallum's (1918) species, Hemistoma haustrum)

, he designated the dividable body (with a spoon-like anterior and a cylindrical posterior part) and, among other things, the presence of the ani (whose existence was only known in some species at that time, Odhner 1911, Ozaki 1925) as its generic characters. On the basis of the species described later (Oshmarin et al. 1961, Shimazu 1989), it became evident that the morphology of these species, involving even the presence of ani, showed considerable variability (Shimazu 1994) but the special structure of the anterior extremity seemingly proved to be a reliable generic character of this genus. The other debatable genus Bianium was set up by Stunkard (1930) for Linton's (1898) species Distomum sp. Later Stunkard (1931) found that this species showed similarities to another species, Psilostomum plicitum Linton, 1928, and he regarded the former to be a synonym of the latter and it was placed in the genus Bianium as its type species, B. plicitum (Linton, 1928) Stunkard, 1930. In the generic diagnosis Stunkard (1936) has listed the following characters in comparison with those of the genus Diploporus (= Diploproctodaeum in part): diverse shape and portion of body; the presence of lateral folds which are not confluent midventrally; suckers are closer in position; testes are less oblique. In the species described later, out of these generic characters, the presence of the lateral folds which are not confluent midventrally proved to be of generic diagnostic value. Other morphological characters displayed considerable variability (Bilqees 1974, Hafeezullah 1970). A major reorganisation among the species of the two genera (Diploproctodaeum, Bianium) was the taxonomic operation when the then known species of the latter genus were transferred to the former genus by Sogandares-Bernal and Hutton (1958) who stated that there was not a single character by which these two genera could be differentiated. This opinion, however, was not shared by several subsequent authors (Gupta 1968, Hafeezullah 1970, Yamaguti 1971, Reimer 1981, Shimazu 1989) and the present author is of the opinion that the two genera in question are closely related but distinct ones. Recently, Reimer (1981) has modified further the scope of the diploproctodeid species setting up the new genus Diploproctodaeoides for his species D. soleaticus and for those having a bulging rim in the spoon-like structure of the anterior extremity. Taking this character into account, Reimer (1981) transferred the species Diploproctodaeum plataxi Mamaev, 1979; D. macroacetabulum Oshmarin, Mamaev et Paruchin, 1961 and D. longipygum Oshmarin, Mamaev et Paruchin, 1961 to the genus Diploproctodaeoides. Apparently, Reimer (1981) did not consult Paruchin's paper in which he had described the species Diploproctodaeum chelodoni having the same anterior body structure (bulging rim). Therefore, it should be allocated to Reimer's (1981) genus as Diploproctodaeoides chelodoni (Paruchin, 1979) n. comb. The geus Diploporus was designated by Ozaki (1928) for the species D. hemistomum and D. cryptosomum. This genus proved to be preoccupied; therefore, D. hemistomum was transferred by Yamaguti (1934) to the genus Bianium and D. cryptosomum by Manter (1947) to the same genus. Later, Sogandares-Bernal and Hutton (1959) transferred D. cryptosomum to the genus Diploproctodaeum. Park (1939) created the genus Diplocreadium for his species D. koreanum and in the generic diagnosis the absence of the ani and the vesicula seminalis interna were designated as the principal generic characters. Later, Hafeezullah (1970) described the second species of the genus (D. triacanthi) in which, however, the presence of the vesicula seminalis interna has been observed. Apparently this state has no generic value similar to the presence or absence of the