Dr. Kassai Tibor - Dr. Murai Éva szerk.: Parasitologia Hungarica 10. (Budapest, 1977)

very narrow stripe towards abdominal part of body. Nerve ring 0. 12 mm and vulva 1. 66 mm from anterior end of body. Anal opening 0.33 mm from posterior end of body. Eggs oval, 0. 22-0. 21 x 0. Ó96-0. 099 mm (Table 1). 0T mm Fig. 2: Aspiculuris tetraptera (Nitzsch, 1821) (Orig. ) A) Anterior end, en face view B) Anterior end, lateral view Notes: This nematode was found only in the locality Oslo in one of the two A. sylvaticus examined. In the locality Kviteseid we examined 50 A. sylvaticus, but this parasite was not found in any of them. According to HALL (1916) A. tetraptera seems to parasitize many rodents, including A. sylvaticus. This author found A. tetraptera in the large intestine of the host. SCHULZ (1924) recovered this nematode not only from the large intestine, but also from the caecum and small intestine of rodents. A. tetraptera was recovered from the small intestine of rodents also by SKRJABIN et al. (1960) and from the caecum of members of the genus Apodemus by TENORA (1963). The main host of A. tetraptera is Mus Musculus. The parasite is most frequently located in the large intestine and caecum occurring in regions varying from lowlands up to high mountains (ERHARDOVÁ and RYSAVY 1955, ERHARDOVÁ 1955). A tetraptera infects other hosts only occasionally and at places were the main hosts, M. musculus occurred. The incidence Ü7