Phylum Mollusca Linnaeus, 1758 - molluscs Class Gastropoda Cuvier, 1795 - snails and slugs Subclass Prosobranchia Milne-Edwards, 1848 - prosobranchs see Class Gastropoda Cuvier, 1795 Superorder Archaeogastropoda Thiele, 1925 Order Vetigastropoda Salvini-Plawen, 1980 - archaeogastropods s.l. Superfamily Fissurelloidea Fleming, 1822 [monotypic] 1 Family Fissurellidae Fleming, 1822 - keyhole limpets