Phylum Mollusca Linnaeus, 1758 - molluscs
   Class Gastropoda Cuvier, 1795 - snails and slugs
     Subclass Heterobranchia Burmeister, 1837 [monotypic] see Superorder Heterobranchia Burmeister, 1837
       Order Heterostropha Fischer, 1885
         Superfamily Pyramidelloidea Gray, 1840
           Family Pyramidellidae Gray, 1840
             Subfamily Odostomiinae Casey, 1904
               Genus Tropeas Pacaud & Le Renard, 1995, orth. inval. see Genus Tropaeas Dall & Bartsch, 1904
                 1 Subgenus Syrnolina Dall & Bartsch, 1904
                 2 Subgenus Ugartea Bartsch, 1917