Phylum Mollusca Linnaeus, 1758 - molluscs
   Class Gastropoda Cuvier, 1795 - snails and slugs
     Subclass Prosobranchia Milne-Edwards, 1848 - prosobranchs see Class Gastropoda Cuvier, 1795
       Superorder Archaeogastropoda Thiele, 1925
         Order Vetigastropoda Salvini-Plawen, 1980 - archaeogastropods s.l.
           Superfamily Trochoidea Rafinesque, 1815
             Family Trochidae Rafinesque, 1815 - top snails
               Subfamily Cataeginae McLean & Quinn, 1987
                 1 Genus Cataegis McLean & Quinn, 1987
                 2 Genus Nanula Thiele, 1924
                 3 Genus Trochinella Iredale, 1937