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 Architaenioglossa Haller, 1890
           Superfamily Cerithioidea Fleming, 1822
             Family Cerithiidae Fleming, 1822 - ceriths
               Subfamily Cerithiinae Fleming, 1822
                 Genus Royella Iredale, 1912