Baikal nematodes of the genus Ethmolaimus (Nematoda: Chromadorida: Ethmolaimidae)

Abstract. Descriptions of four species of Baikal nematodes of the genus Ethmolaimus de Man, 1880 are given. Three species are new. E. derisorius sp. n. differs from all species of the genus in the exteremely high position of the excretory duct of the renette. E. pilosus sp. n. differs from all species of the genus in the extremely long somatic setae. E. lanatus sp. n. differs from E. pilosus sp. n. in the longer cephalic setae, finer punctation and smaller size of spicules. E. revaliensis (G. Schneider, 1906) Steiner, 1913 is recorded for the first time from Baikal.