Superclass Spirotricha Bütschli, 1889 see Class Spirotrichea Bütschli, 1889
   1 Class Hypotrichea Stein, 1859 see Subclass Hypotrichia (Stein, 1859) Cavalier-Smith, 1993
   2 Class Oligotrichea Bütschli, 1889 see Subclass Oligotrichia Bütschli, 1889