Class Gastropoda Cuvier, 1795 - snails and slugs Subclass Prosobranchia Milne-Edwards, 1848 - prosobranchs see Class Gastropoda Cuvier, 1795 Order Mesogastropoda Thiele, 1925 - mesogastropods see [unranked] mesogastropods Superfamily Clavacea Family Turritellidae Lovén, 1847 - turret snails Genus Mesalia Gray, 1847 Subgenus †Sigmesalia Finlay & Marwick, 1937 see Genus Sigmesalia Finlay & Marwick, 1937 †Mesalia fasciata (Lamarck)