Phylum Mollusca Linnaeus, 1758 - molluscs Class Gastropoda Cuvier, 1795 - snails and slugs Subclass Gymnomorpha Salvini-Plawen, 1970 see Subclass Pulmonata Cuvier, 1814 Order Onchidiida Solem, 1959 [monotypic] Superfamily Onchidioidea Rafinesque, 1815 [monotypic] Family Onchidiidae Rafinesque, 1815 Genus Onchidella Gray, 1850