EN
Two new species of the genus Iotonchus and Coomansus zschokkei (Menzel, 1913) are described and illustrated. Iotonchus uisongensis sp. nov. is 1.5-1.6mm long, a=23.0-26.0, b=2.8-3.2, c=17.1-19.4 (female) and 19.6-23.0 (male), V=67.0-73.0, buccal cavity=52.0-63.0 x 31.0-36.5 µm, spicule 75.0-92.0 µm long, ventromedian supplements papillae 20-22 in numbers, and is characterized by having not protruded labial papillae, supra basal dorsal tooth, and flattened basal oblique plates of buccal cavity. Iotonchus damsanensis sp. nov. is 1.6-1.7mm long, a= 19.7-22.0, b=2.9-3.0, c=17.2-21.7, V=71.0-74.5, buccal cavity=58.0-61.0 x 35.0-37.0 µm, and is characterized by having offset lip region, well protruded labial papillae, basally tapered buccal cavity, and in having pre-vulval papillae. Coomansus zschokkei reported here for the first time from Korea is also described in detail with variation in the shape of male tail.