Type host. Greater scaup, Aythya marila (Linnaeus) (Anseriformes: Anatidae).
Type locality. Russian Federation; specific type locality unknown.
Remarks. Savinov (1960) could not be obtained; however, McDonald (1969 a, 1969 b, 1981) has provided a limited amount of additional information concerning this species, including an illustration (Fig. 17.2), but gave no measurements. McDonald (1981) indicated that there was a bean-shaped supplementary body attached to the posterior end of each testis. Such a structure would be unusual, but in senescing adult flukes it is not unusual to have the peripheries of the testes separate from the parenchyma leaving a space that might be construed as an additional structure. As far as we can determine this species was never adequately described and should be considered a species inquirenda and it was not included in our key to the species currently assigned to Hyptiasmus. No oral or ventral sucker described—McDonald, (1981).