Phylum Mollusca Linnaeus, 1758 - molluscs Conchifera Gegenbaur, 1878 see Subphylum Conchifera Gegenbauer, 1878 Cyrtosoma Class Gastropoda Cuvier, 1795 - snails and slugs Subclass †Dextrobranchia Minichev & Starobogatov, 1979 1 Order †Onychochiliformes Starobogatov, 1984