Phylum Mollusca Linnaeus, 1758 - molluscs Class Gastropoda Cuvier, 1795 - snails and slugs Subclass Divasibranchia Minichev & Starobogatov, 1975 Order Basommatophora Keferstein, 1865 see Suborder Basommatophora Keferstein, in Bronn, 1864 Superfamily Siphonarioidea Gray, 1827 Family Trimusculidae Burch, 1945 (1840) [monotypic] 1 Genus Trimusculus Schmidt, 1818