Description of three new species of Geomonhystera (Nematoda: Monhysterida)

Abstract. Geomonhystera longicaudata sp. n. from Israel is close to G. australis (Cobb, 1893), but differs in the shorter body, longer cephalic and labial setae, longer tail and absence of stomatal denticles. G. media sp. n. from the Ukraine and Australia is close to G. maxicana (Brzeski, 1993), but differs in the longer cephalic and labial setae, more posteriorly situated amphidial opening, and absence of stomatal denticles. G. altaica sp. n. from Russia is close to G. longicaudata, but differs in the shorter cephalic and labial setae and in the ratio vulva-anus distance to anal diameter. G. australis (Cobb, 1893), G. breviseta (Brzeski, 1993), G. mexicana (Brzeski, 1993), G. longicaudata sp. n., G. media sp. n., G. altaica sp. n. are very similar and form within the genus the G. australis species-group. A key to species of this group is given.