Phylum Ciliophora Doflein, 1901 - ciliates
   Subphylum Intramacronucleata Lynn, 1996 - amphiesmates
     Class Oligohymenophorea de Puytorac et al., 1974 - oligohymenophoreans
       1 Subclass Peniculia Fauré-Fremiet, 1956
       2 Subclass Scuticociliatia (E.B. Small, 1967)
       3 Subclass Hymenostomatia (Delage & Hérouard, 1896) Cavalier-Smith, 1993 - hymenostome ciliates
       4 Subclass Apostomatia Chatton & Lwoff, 1928
       5 Subclass Peritrichia Stein, 1859
       6 Subclass Astomatia Schewiakoff, 1896