Morphology of Tripylidae is discussed and the family rediagnosed. The genera Tripyla Bastian, 1865 (= Promononchus Micoletzky, 1923, Paratripyla Brzeski, 1963, syn. n.), Tripyella gen. n. and Tripylina Brzeski, 1964 are included in this family. Abunema Khera, 1971 and Trischistoma Cobb, 1913 are removed from Tripylidae. Tripyla contains 16 species, including three new ones. T. aquatica sp. n. has a thin body about 2 mm long, outer labial sensillae bent anteriad 5-6 mum long, small stomatal chamber, elongated tail (c' = 6.1-8.6). T. elegantula sp. n. is about 2 mm long, thin, has very small inner labial papillae, outer labial sensillae 3-5 pm long, dorsal tooth and stomatal chamber large, long tail (c' = 8-10). T. terricola sp. n. is about 1 mm long, has rather stout body with short curved tail, anterior sensory organs very small. T. infia nom. n. is proposed for T. filipjevi Altherr in Altherr & Delamare Deboutteville, 19 7 2, nec Promononchus filipjevi Micoletzky, 1923 (= T. glomerans Bastian, 1865). T. minuta (Brzeski, 1963) comb. n. is proposed for the type species of the genus Paratripyla Brzeski, 1964. Tripylella gen. n. is a monotypic genus proposed to accomodate T. intermedia (Butschli, 1873) comb. n. This genus is differentiated by having two stomatal chambers, outer labial and cephalic sensillae in one whorl, large cardiac glands composed of six fused cells, wide horn shaped spicules and row of supplementary papillae reaching pharyngeal region, Tripylina contains six species. T. longa sp. n. is 1.5-1.7 mm long, subventral teeth anterior to large dorsal tooth, two cervical ventromedian setae and posterior vulva (V = 76-80). Male of T. longa has narrow sickle shaped spicules and five supplementary papillae confined to cloacal region. Keys for species identification of Tripyla and Tripylina are provided.
