Kingdom Protista (Haeckel, 1866) - protists Phylum Ciliophora Doflein, 1901 - ciliates Class Oligohymenophorea de Puytorac et al., 1974 - oligohymenophoreans Subclass Hymenostomatia (Delage & Hérouard, 1896) Cavalier-Smith, 1993 - hymenostome ciliates Genus Colpidium Stein, 1860 Genus Paramecium Müller, 1773 Genus Tetrahymena Furgason, 1940