Mohammad Rafiq Siddiqi2014-09-172014-09-171982Systematic Parasitology 4, 69-87(1982)http://hdl.handle.net/123456789/5782New genera described from soil in Colombian rain forest are Fuscheila (Thornenematidae), Capilon-chus (Tylencholaiminae, Tylencholaimidae), Cave-onchus (Tyleptinae, Leptonchidae), Coronatyleptus (Belonenchinae, Leptonchidae), Promumtazium (Mumtaziinae, Tylencholaimidae), Tantunema (Thorniinae, Tylencholaimidae) and Zalophidera (Xiphinemellinae, Tylencholaimidae). 12 new species belonging to these genera described and illustrated are: Fuscheila citrifera (type species), F. godmanae, Capilonchus lineatus (type-species), Caveonchus colombicus (type species), C. brevi-saccus, Coronatyleptus barbarae, C. curvus, C. ro-bustus, Promumtazium pyxidorum (type species), Tantunema bothriocephalum (type species), Zalophidera tylocephala (type species) and Z. idiostoma. Caveonchus saccatus (Goseco, Ferris & Ferris, 1981) n. comb, and Coronatyleptus coronatus (Siddiqi & Khan, 1965) n. comb, (type-species) are made for Basirotyleptus saccatus and B. coronatus, respectively. The composition of the families Leptonchidae and Tylencholamidae is discussed and Leptonchoidae Thorne, 1935 (Ferris, 1970) is made a junior synonym of Tylencholaimoidea Filipjev, 1934 (n.rank).enArticle