Phylum [Mollusca] Linnaeus, 1758 - molluscs
   Class Gastropoda Cuvier, 1795 - snails and slugs
     Subclass Prosobranchia Milne-Edwards, 1848 - prosobranchs see Class Gastropoda Cuvier, 1795
       Order Neogastropoda Wenz, 1938 see Suborder Neogastropoda Wenz, 1938
         Suborder Toxoglossa (Troschel, 1848) see Superfamily Conacea Rafinesque, 1815
           Superfamily Conacea Rafinesque, 1815 see Superfamily Conoidea Fleming, 1822
             Family Cancellariidae Forbes & Hanley, 1851 - nutmeg snails
               Subfamily Trigonostomoninae F.J. Springsteen & F.M. Leobrera, 1986 see Subfamily Trigonostomatinae Cossmann, 1899
                 Genus Trigonostoma Blainville, 1827