Dr. Kassai Tibor - Dr. Murai Éva szerk.: Parasitologia Hungarica 7. (Budapest, 1974)

mum

, from the intestine of Nyroca nyroca. A new species was reported by SKWORTZOW (1934) from the rodent Arvicola terrestris. This species was found later by several authors in aquatic mammals. In Hungary it has been found by SEY (1965a). GRABDA(1954) described a new Psilotrema species, parasitizing in the small intestine of Ondatra zibethica, under the name P

. pharyngeatum

. Later several authors have also described this species from other aquatic mammals (POJMANSKA, 1957; ERHARDOVÁ, 1958; EDELÉNYI, 1966). MERKUSHEVA (1958) reported two fluke species, P. simillimum and P. spiculigerum

. parasitizing Arvicola terrestris. She stated that the species P. pharyngeatum Grabda, 1954, living in rodents, and P. simillimum (Mühling. 1898), occurring in birds, represent the same species, so that P

. pharyngeatum is the junior synonym of P. simillimum (MERKUSHEVA, -1959). AHÜREJK0, PIHCHUK and SKWORTZOW (1963) agree with MERKUSHEVA'

s opinion. The relationship of P. spiculigerum to P. marki was not discussed by MERKUSHEVA, although the trematode species living in rodents (Arvicola terrestris) was first published by her as P

. spiculigerum

. This species was published earlier only from birds, ' whereas the species P. marki

, very similar to P. spicu ligerum

, was reported only from mammals

. BIKHOVSKAYA-PAVLOVSKAYA

, RYJIKOV and KHOTENOVSKY (1966), referring to WARTEJUK (1958) regard the fluke P. spiculigerum (Mühling, 1898), occurring in Anserif

ormes

, as the junior synonym of P. oligoon (Linstow, 1887). WERTEJUK compares the body and organ measurements and the position of organs of his trematode material originating from geese with those described in the literature. In his opinion P. spiculigerum differs from P. oligoon , according to the original description, by a single characteristic only: the smooth tegument of the former against the spinous one of the latter. According to WERTEJUK (1958) as well as BIKHOVSKAYA-PAVLOVSKAYA et al. (1966) the smooth integument develops artificially under the effect of fixation, hence this characteristic should not be considered for the establishment of a new species. The statement of the above authors is correct