Phylum Mollusca Linnaeus, 1758 - molluscs Class Gastropoda Cuvier, 1795 - snails and slugs Subclass Prosobranchia Milne-Edwards, 1848 - prosobranchs see Class Gastropoda Cuvier, 1795 Order Caenogastropoda Cox, 1960 see Superorder Caenogastropoda Cox, 1960 Superfamily Rissooidea Gray, 1847 Family Iravadiidae Thiele, 1928 Genus Hyala Adams & Adams, 1852