Species (22.489)
- Hypocomagalma pholadidis Kozloff 1946
- Hypocomatophora unionidarum Jarocki & Raabe 1932
- Hypocomella katharinae Kozloff 1961
- Hypocomella cardii Chatton & Lwoff 1922
- Hypocomides astartae Fenchel 1965
- Hypocomides modiolariae Chatton & Lwoff 1922
- Hypocomina patellarum Lichtenstein 1921
- Hypocomidium fabius Raabe 1938
- Hypocomina tegularum Kozloff 1946
- Hypophrya fasciculata Lorez-Ochoterena 1964
- Hypotrichidium conicum Ilowaisky 1921
- Hypotrichidium tisiae Gelei 1929
- Ichthyonyctus baueri Ky 1971
- Ichthyonyctus carinii
- Ichthyonyctus pangasia
- Ichthyonyctus dilleri
- Ichthyonyctus piscicola
- Ichthyonyctus schulmani Ky 1971
- Ichthyophthirioides browni Roque & Puytorac 1967
- Ichthyophthirius cryptostomus Zacharias 1893
- Ichthyophthirius multifiliis Fouquet 1876
- Ichtyophyllum tectiformis Scheubel 1973
- Idiocolpoda pelobia Foissner 1993
- Iduna sulcata Claparède & Lachmann 1859
- Ignotocoma sabellarum Kozloff 1961
- Ignotocoma venusta Kozloff 1946
- Ilsiella palustris Foissner 1993
- Imperfecta subantarcticum Busch 1948
- Indonyctus marina Santhakumari & Nair ()
- Inermichona patella Jankowski 1971
- Inermichona grindleyi Jankowski 1971
- Inermichona somatica Jankowski 1971
- Inferostoma jankowskii Ky 1971
- Infundibulorium cameli Bozhenko 1925
- Insignicoma venusta Kozloff 1946
- Insectinicola medians Collin 1909
- Intoshellina limnodrili Katashima 1952
- Intoshellina cheissini Puytorac 1972
- Intoshellina ochridana Puytorac 1960
- Intoshellina maupasi Cepede 1910
- Intoshellina poljanskyi Cepede 1930
- Intoshellina sapkarevi Puytorac 1960
- Isochona antennaria Jankowski 1973
- Isochona crassa Jankowski 1973
- Isochona migratoria Jankowski 1973
- Isochona peltifera Jankowski 1973
- Isochona pleonicola Jankowski 1973
- Isochona rotundata Jankowski 1973
- Isocomides mytili C & L 1928
- Isopodarcon multicapitatum Kent 1882
- Isotricha intestinalis Stein 185?
- Isselina intermedia Cépède 1910
- Jankowskia mobilis Alekperov 1984
- Kahliella bacilliformis Gelei 1954
- Kalometopia duplicata Penard 1922
- Kahlilembus fusiformis Kahl 1926
- Kalometopia eurystoma Gellert 1950
- Kellicotta cuspidata Kellicott 1885
- Kentrochona robusta Jankowski 1973
- Kentrochonopsis multipara Doflein 1897
- Kentrophoros faurei Dragesco 1954
- Kentrophoros flavum Raikov & Kovaleva 1968
- Hydrochoerella intestinalis Cunha & Muniz 1925
- Hydrophrya miyashitai Nozawa 1938
- Hymenostoma hymenophora Stokes 1884
- Hymenostoma magna Stokes 1887
- Hypocoma parasitica Gruber 1884
- Hypocoma rostellum Deroux 1976
- Hypocomagalma dreissenae Jarocki & Raabe 1932
- Hypocomatidium sphaerii Jarocki & Raabe 1932
- Hypocomides botulae Kozloff 1946
- Hypocomides elsinoia Fenchel 1965
- Hypocomides kelliae Kozloff 1946
- Hypocomides parva Kozloff 1946
- Hysterocineta plaudinarum Diesing 1866
- Hysterocinetoides intermedius Ngassam 1994
- Hysterophrya enigmatica Puytorac, Gloriere & Grain 1979
- Ileonema ciliata Roux 1901
- Ileonema dispar Stokes 1884
- Ilsiella venusta Foissner 1987
- Ileonema simplex Penard 1922
- Intoshellina sicyodes Georgevitch 1941
- Intoshellina wautieri Puytorac & Juget 1964
- Intranstylum aselli
- Kerona tremula Dumas 1929
- Kerona truncata Dumas 1929
- Kerona unguicularis Dumas 1937
- Keronella gracilis Wiackowski 1985
- Keronopsis algivora Gellert 1942
- Keronopsis alpestris Kahl 1932
- Keronopsis arenicola Dragesco 1963
- Keronopsis arenivora Dragesco 1954
- Keronopsis flavicans Kahl 1932
- Keronopsis dieckmanni Foissner 1998
- Keronopsis decolor Wallengren 1900
- Keronopsis coronata Gourret & Roeser 1888
- Keronopsis flavorubra Entz 1884
- Keronopsis globulifera Kahl 1932
- Keronopsis fontinalis Lepsi 1926
- Keronopsis gracilis Kahl 1932