Order Hymenostomatida Delage & Hérouard, 1896

Suborder Tetrahymenina Fauré-Fremiet in Corliss, 1956

Fam. Curimostomatidae Jankowski, 1968
Fam. Glaucomidae Corliss, 1971
Fam. Spirozonidae Kahl, 1926
Fam. Trichospiridae Kahl, 1926
Fam. Tetrahymenidae Corliss, 1952
Fam. Turaniellidae Didier, 1971

Suborder Ophryoglenina Canella, 1964

Fam. Ichthyophthiriidae Kent, 1881
Fam. Ophryoglenidae Kent, 1881

Incertae sedis in Order Hymenostomatida

- Blepharostoma Schewiakoff, 1893 [1892; nomen nudum]