[Kingdom] Animalia Linnaeus, 1758 - animals
   Grade Plastidozoa [monotypic]
     [Phylum] Protozoa (Goldfuss, 1818) C.T. von Siebold, 1854 see Kingdom Protozoa Goldfuss, 1818
       Grade Stomatodea
         Class Ciliata see [unranked] ciliates
           1 Order Holotricha
           2 Order Heterotricha Stein, 1859 see Suborder Heterotricha Stein, 1859
           3 Order Hypotricha see Suborder Hypotricha Stein, 1859
           4 Order Peritricha Stein, 1859
           5 Order Calycata