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 Acteonoidea d'Orbigny, 1843 Family Aglajidae Pilsbry, 1895 (1847) Genus Chelidonura Adams, 1850