Species (22.489)
- Trichodoxa phalli Sirgel 1983
- Trichophrya viridis Dumas 1930
- Trichophysea sinuosa Shawahan, Johnson & Jahn 1947
- Trichopodiella dysteria Claparède & Lachmann 1859
- Trichopodiella elongata Deroux 1976
- Trichospira cincinnata Penard 1922
- Trichospira dextrorsa Roux 1899
- Trichotaxis caudata Ehrenberg 1838
- Trichotaxis aquarum Bürger 1906 ssp. dulcium
- Trichotaxis euplotes Dragesco 1960
- Trichotaxis crassa Claparède & Lachmann 1858
- Trichotaxis pulchra Borror 1972
- Trichotaxis fossicola Kahl 1932
- Trichotaxis multinucleatus Burkovsky 1970
- Trichotaxis rubentis Sarmiento & Guerra 1960
- Trichotaxis stagnatilis Stokes 1891
- Trichotaxis velox Quennerstedt 1869
- Trichotaxis villaensis Sarmiento & Guerra 1960
- Trichototaxis aeruginosa Foissner 1980
- Trichototaxis pulchra Borror 1972
- Trichototaxis rubentis Sarmiento & Guerra 1960
- Trichototaxis villaensis Sarmiento & Guerra 1960
- Tricodon biuncinatus Dumas
- Trichototaxis stagnatilis Stokes 1891
- Tricoronella pulchra Blatterer & Foissner 1988
- Trihymena terricola Foissner 1988
- Trimyema alfredkahli Tucolesco 1962
- Trimyema claviformis Kahl 1933
- Trimyema compressa Lackey 1925
- Trimyema kahli Tucolesco 1962
- Trithigmostoma alpestris Foissner 1979
- Triplumaria hamertoni Hoare 1937
- Trochilioides dubia Wallengren 1903
- Trochilioides oculata Kahl 1933
- Trochilioides littoralis Jankowski 1967
- Trochilioides striata Buddenbrock 1920
- Trochilioides recta Kahl 1928
- Trochilioides tenuis Deroux 1976
- Trochilioides trivialis Fenchel 1965
- Trochiliopsis opaca Penard 1922
- Trochiliopsis australis Foissner, Skogstad & Pratt 1988
- Trochochilodon flavum Deroux 1976
- Troglodytella abrassarti Brumpt & Joyeux 1912
- Troglodytella gorillae Reichenow 1917
- Trophogemma poljanskyi Jankowski 1970
- Tucolesca mirabilis Tucolesco 1962
- Trypanococcus rotiferorum Stein 1885
- Turaniella vitrea Brodsky 1925
- Tracheloraphis dicaryon Raikov 1963
- Tracheloraphis enigmaticus Dragesco 1960
- Tracheloraphis flexuosus Raikov & Kovaleva 1968
- Tracheloraphis griseus Kahl 1933
- Tracheloraphis haloetes Borror 1973
- Tracheloraphis hamatus Wright 1982
- Tracheloraphis hyalinum Dragesco 1960
- Tracheloraphis incaudatus Kahl 1933
- Tracheloraphis sarmaticus Agamaliev & Kovaleva 1966
- Tracheloraphis stephani Dragesco 1965
- Tracheloraphis stratius Raikov 1962
- Tracheloraphis sulcata Kovaleva 1966
- Tracheloraphis swedmarki Dragesco 1960
- Tracheloraphis teissieri Dragesco 1960
- Tracheloraphis totevi Kovaleva & Golemanski 1979
- Tracheloraphis vermiformis Raikov 1962
- Trachelostyla affine
- Trachelostyla bryonicolum Gellert 1956
- Trachelostyla caudata Kahl 1932
- Trachelostyla canadensis Buitkamp & Wilbert 1974
- Trachelostyla ciliophorum Gellert 1956
- Trachelophyllum hyalinum Foissner 1983
- Trachelophyllum fontinale Penard 1922
- Trachelophyllum lineola Dumas 1937
- Trachelophyllum pilosum Penard 1922
- Trachelophyllum vestitum Stokes 1884
- Tracheloraphis angustivittata Borror 1973
- Tracheloraphis aragoi Dragesco 1954
- Tracheloraphis beninensis Dragesco & Dragesco-Kernéis 1986
- Tracheloraphis arenicolis Sauerbrey 1928
- Tracheloraphis bodiani Dragesco 1963
- Tracheloraphis caudatus Dragesco & Raikov 1966
- Tracheloraphis conformis Wright 1982
- Tracheloraphis crassus Raikov 1962
- Tracheloraphis coniformis Wright 1982
- Tracheloraphis discolor Raikov 1962
- Tracheloraphis dogieli Raikov 1957
- Vaginicola inclinata Fromentel 1876
- Vaginicola incisa Daday 1907
- Vaginicola lagena Kahl 1935
- Vaginicola tincta Ehrenberg 1830
- Valletofolliculina bicornis Andrews 1953
- Veracineta tisbei Guilcher 1950
- Vesonyctus vachoni Albaret ()
- Vestibulongum corlissi Grim 1988
- Vibrio anser Müller 1773
- Vibrio cygnus Müller 1773
- Vibrio fasciola Müller 1773
- Vibrio olor Müller 1786
- Vinarcon asteris Jankowski 1981
- Vaginicola leptosoma Stokes 1885
- Vaginicola lobata Daday 1907