organisms see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Domain eukaryotes see Domain Eukaryota Chatton, 1925
     alveolates Cavalier-Smith see [unranked] Alveolata Cavalier-Smith, 1991
       Phylum Ciliophora Doflein, 1901 - ciliates
         Subphylum Intramacronucleata Lynn, 1996 - amphiesmates
           Class Prostomatea Schewiakoff, 1896
             Order Prostomatida Schewiakoff, 1896
               Family Metacystidae Kahl, 1926
                 1 Genus Metacystis Cohn, 1866
                 2 Genus Pelatractus Kahl, 1930
                 3 Genus Vasicola Tatem, 1869