Dr. Murai Éva szerk.: Parasitologia Hungarica 12. (Budapest, 1979)

NEMATODA Heligmosomum costellatum (Dujardin, 1845) Hosts: Microtus agrestis, M. nivalis, Pitymys subterraneus. - Location: small intestine. Common parasite of Microtinae. Mentioned from Microtus arvalis by CHIRIAC and HAMAR (1966), CHIRIAC and BARBU (1963), POPESCU and BARBU (1971). Heligmosomum mixtum Schulz, 1954 (Fig. 9) Host: Clethrionomys glareolus. - Location: small intestine. Synlophe: Dorsal surface of body with transversal, ventral surface with longitudinal Fig. 9: Heligmosomum mixtum Schulz, 1954 Anterior end of female cuticular ridges (crête), numbering 20-21. Ridges present from just behind vesicle to bursa in males, to vulva in females. Male: Body length 11.0-11.1 mm, maximum width 0. 22 mm. Esophagus length 0. 500.61 mm. Nerve ring 0.25 mm, excretory pore and deirids 0. 38-0. 50 mm from anterior end. Bursa copulatrix symmetrical, ridge arrangement the same as at the other species of this genus. Paired threadlike spicules 0.86-0.93 mm. Gubernaculum absent. Female: Body length 18.9-19.6 mm, maximum width 0.30 mm. Esophagus length 0.70-0. 75 mm. Nerve ring 0.30 mm, excretory pore and deirids 0. 50-0. 53 mm from anterior end. Distance of vulva 0. 35-0. 40 mm, that of anus 0. 074-0. 090 mm, from posterior end. Tail end with terminal spike. It is a common parasite of C. glareolus. So far it has been unknown in the area under examination. Taxonomic and propagation data for this species have been summarized by MÉSZÁROS (1978).