Kingdom Protista (Haeckel, 1866) - protists
   Phylum Ciliophora Doflein, 1901 - ciliates
     Class Oligohymenophorea de Puytorac et al., 1974 - oligohymenophoreans
       1 Subclass Hymenostomatia (Delage & Hérouard, 1896) Cavalier-Smith, 1993 - hymenostome ciliates
       2 Subclass Peritricha Stein, 1859 - peritrichs see Subclass Peritrichia Stein, 1859