Phylum Mollusca Linnaeus, 1758 - molluscs Class Gastropoda Cuvier, 1795 - snails and slugs Subclass Divasibranchia Minichev & Starobogatov, 1975 Order Stylommatophora Schmidt, 1855 see Infraorder Stylommatophora Schmidt, 1855 (Helicid Sigmurethra) Superfamily Trigonochlamydoidea Hesse, 1882 [monotypic] see Superfamily Parmacelloidea Fischer, 1856 (1855) 1 Family Trigonochlamydidae Hesse, 1882