Phylum [Mollusca] Linnaeus, 1758 - molluscs Class Gastropoda Cuvier, 1795 - snails and slugs Subclass Opisthobranchia Milne-Edwards, 1848 - opisthobranchs see Order Opisthobranchia Milne-Edwards, 1848 Order Cephalaspidea Fischer, 1883 Superfamily Bullacea see Superfamily Bulloidea Gray, 1827 Family Bullidae Gray, 1827 Genus Bulla Linnaeus, 1758