Family Oxytrichidae Ehrenberg, 1838
   Subfamily Stylonychinae H. Berger & W. Foissner, 1997
     1 Genus Coniculostomum Njiné, 1979
     2 Genus Histriculus Corliss, 1960
     3 Genus Steinia Diesing, 1866
     4 Genus Sterkiella Foissner et al., 1991
     5 Genus Stylonychia Ehrenberg, 1830
     6 ?Genus Parastylonychia Dragesco, 1963
     7 ?Genus Pleurotricha Stein, 1859