Phylum Mollusca Linnaeus, 1758 - molluscs
   Class Gastropoda Cuvier, 1795 - snails and slugs
     Subclass Prosobranchia Milne-Edwards, 1848 - prosobranchs see Class Gastropoda Cuvier, 1795
       Order Caenogastropoda Cox, 1960 see Superorder Caenogastropoda Cox, 1960
         Suborder Neotaenioglossa Haller, 1882 see Order Sorbeoconcha Ponder & Lindberg, 1997
           Superfamily Trivioidea F.H. Troschel, 1863 see Superfamily Velutinoidea Gray, 1840
             Family Ovulidae Fleming, 1822 - egg snails
               Subfamily Ovulinae Fleming, 1822
                 Tribe Simniini Schilder, 1927 see Tribe Ovulini Fleming, 1822
                   01 Genus Volva Röding, 1798
                   02 Genus Aclyvolva Cate, 1973
                   03 Genus Cymbovula Cate, 1973
                   04 Genus Dissona Cate, 1973
                   05 Genus Hiatavolva Cate, 1973
                   06 Genus Kuroshiovolva Azuma & Cate, 1971
                   07 Genus Phenacovolva Iredale, 1930
                   08 Genus Prosimnia Schilder, 1927
                   09 Genus Simnia Risso, 1826
                   10 Genus Simnialena Cate, 1973
                   11 Genus Subsimnia Cate, 1973