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

In Hungary, the species was first found by SEY (1966) in the small intestine of Ondatra. Unfortunately the measurements of the pharynx and the ratio of the pharynx and the oral sucker were not published in the description, but the figure clearly shows that the pharynx of the species collected by SEY is smaller than the oral sucker. The measurements of the specimens in our collection are given in Table 3« The data given by the various authors of the species P. spiculigerum (Mühling, 1898) and P • marki (Skwortzow, 1934-) are summarized in this table. A comparison of the data given in the table shows no significant differences between the body and organ measurements of the two species, described by MÜHLING and SKWORTZOW, respectively. According to SKWORTZOW, the distinction between P. marki and P

. spiculigerum is, among others, based on different sizes of the suckers and the cirrus-pouch of the respective species. There are differences also in the spinosity of the tegument, the position of the follicles, the different number of the eggs and the stage of development of the excretory system. If we compare these features with the original description and with those published recently from birds under the name P. spiculigerum (BIKHOVSKAYA-PAVLOVSKAYA, RYJIKOV and KHOTENOVSKY, 1966) one may state that these differences do not exist at all (e.g. the spinosity of the tegument), or they are within the ranges of individual variability (e.g. the size and position of the follicles, the development of the excretory system). The number of eggs varies between one and 15-20 per exemplar; their greater number cannot therefore be a characteristic feature of P. marki

. According to SKWORTZOW, a differentiating feature is the difference between the hosts, but in the knowledge of the life cycle of this fluke species, now we cannot consider this difference as characteristic. The cercariae leaving the water-snail encyst on aquatic plants. Adult worms develop in the gut of the final host, which consume aquatic plants. MATHIAS (cit. WERTEJUK) proved experimentally that also the white mouse can be infected besides the domestic duck, and the adult specimens of P. spiculigerum develop also in mammals. P_. marki was described by SKWORTZOW from Arvicola terrestris. It