Eudorylaimus chukotkanus sp. n. and E. mylnikovi sp. n. (Nematoda: Dorylaimida) from Lake El’gygytgyn (Chukotka, Russia)

Two new nematode species of the genus Eudorylaimus Andrássy, 1959 found in Lake El’gygytgyn (Chukotka, Russia)— E. chukotkanus sp. n. and E. mylnikovi sp. n.—are described and illustrations are provided. E. chukotkanus sp. n. is close to E. similis (de Man, 1876) and E. imitatoris Gagarin, 1982. It differs from both species by a longer body and odontostyle, comparatively longer prerectum, longer spicules, more numerous precloacal supplements, and a less slender tail. E. mylnikovi sp. n. is morphologically close to E. chukotkanus sp. n., but it has a shorter body and odontostyle, a different shape of the vulva, shorter tail and spicules, and less numerous ventromedial supplements. The genus Arctidorylaimus Mulvey, Anderson, 1979 has lost its status as an independent taxon and is reduced to a synonym for the genus Eudorylaimus Andrássy, 1959. The morphological diagnosis of the genus Eudorylaimus is expanded.