Species (22.489)
- Keronopsis helluo Penard 1922
- Keronopsis heptasticha Kahl 1932
- Keronopsis herbicola Kahl 1932
- Keronopsis macrostoma Dragesco 1970
- Keronopsis multinucleata Maupas 1883
- Keronopsis longissima Dragesco & Dragesco-Kernéis 1986
- Keronopsis monilata Kahl 1928
- Keronopsis multiplex Ozaki & Yagiu 1941
- Keronopsis multistilata Kahl 1928
- Keronopsis muscicola Kahl 1932
- Keronopsis ovalis Kahl 1932
- Keronopsis muscorum Kahl 1932
- Keronopsis pernix Wrzesniowski 1877
- Keronopsis pentasticha Kahl 1932
- Keronopsis pseudorubra Kaltenbach 1960
- Keronopsis polychaeta Borror 1966
- Keronopsis pulchra Kahl 1932
- Keronopsis retrovacuolata Tucolesco 1952
- Keronopsis spectabilis Kahl 1932
- Keronopsis rubra Ehrenberg 1838
- Keronopsis similis Stokes 1886
- Keronopsis sphagni Groliere 1975
- Keronopsis wetzeli Wenzel 1953
- Keronopsis tasmaniensis Blatterer & Foissner 1988
- Kidderia mytili Morgan 1925
- Kiitricha marina Nozawa 1941
- Kolpoda assimilis Müller 1786
- Kofoidella eleutheriae Cépède 1910
- Kindella pacifica Jankowski 1967
- Kolpoda cucullulus Müller 1786
- Kolpoda cucullus Müller 1773
- Kolpoda lamella Müller 1773
- Kolpoda meleagris Müller 1773
- Kondylostoma patens Claparède & Lachmann 1858
- Kozloffia catenula Puytorac 1968
- Kopperia intestinalie Corliss 1960
- Kozloffiella phoronopsidis Kozloff 1945
- Krassniggia auxiliaris Foissner 1987
- Kreyella minuta Foissner 1979
- Kreyella muscicola Kahl 1931
- Kudoella praenucleatum Kudo & Meglitsch 1938
- Kudoella pyriformis Chakravarty & Chatterjee 1957
- Kryoprorodon arcticum Alekperov & Mamajeva 1992
- Kuehneltiella terricola Foissner 1990
- Kuehneltiella muscicola Foissner 1993
- Kyaroikeus cetarius Sniezek, Coats & Small 1995
- Kysthothigma bacteriophila Miyashita 1933
- Lacrymaria balechi Dragesco 1954
- Lacrymaria australis Foissner & O'Donoghue 1990
- Lacrymaria cucumis Penard 1922
- Lacrymaria coronata Claparède & Lachmann 1859
- Lacrymaria cupifera Kahl 1933
- Lacrymaria lagynus Gelei 1954
- Lacrymaria longissima Dragesco 1966
- Lacrymaria maurea Dragesco 1965
- Lacrymaria marina Meunier 1907
- Lacrymaria metabolica Bürger 1908
- Lacrymaria minima Kahl 1927
- Lacrymaria monilata Agamaliev 1966
- Lacrymaria multinucleata Dragesco 1954
- Lacrymaria minuta Dragesco 1963
- Lacrymaria olor Müller 1786
- Lacrymaria phialina Svec 1907
- Lacrymaria phyalina Penard 1922
- Lacrymaria ovata Burkovsky 1970
- Lacrymaria proteus Müller 1786
- Lacrymaria pulchra Wenzel 1953
- Lacrymaria pumilo Vuxanovici 1962
- Lacrymaria pupula Müller 1786
- Lacrymaria rostrata Kahl 1935
- Lacrymaria putrina Kahl 1926
- Lacrymaria rugosa Ehrenberg 1831
- Lacrymaria rotundata Dragesco 1954
- Lacrymaria salinaris Kahl 1928
- Lacrymaria salinarium Kahl 1928
- Lacrymaria sapropelica Kahl 1927
- Lacrymaria sphaerica Lepsi 1962
- Lacrymaria striata Gulati 1926
- Kentrophoros grande Dragesco 1954
- Kentrophoros lanceolatum Faure-Fremiet 1951
- Kentrophoros latum Raikov 1962
- Kentrophoros gracilis Raikov 1963
- Kentrophoros longissimum Dragesco 1954
- Kentrophoros minutum Dragesco 1960
- Kentrophoros ponticum Kovaleva 1966
- Kentrophoros trichocystum Dragesco 1954
- Kentrophyllum antarcticum Petz, Song & Wilbert 1995
- Kentrophoros uninucleatum Raikov 1962
- Kentrophoros tubiforme Raikov & Kovaleva 1966
- Kerona absidata Dumas 1930
- Kerona anfracta Dumas 1929
- Kerona arcuata Dumas 1929
- Kerona aper Fromentel 1876
- Kerona becciformis Dumas 1929
- Kerona bicaudata Dumas 1937
- Kerona calvaeformis Dumas 1929
- Kerona bipes Dumas 1937
- Kerona caudata Dumas 1929
- Kerona congyrans Dumas 1929
- Kerona ciliata Gourret & Roeser 1888