Mollusca Linnaeus, 1758 - molluscs see Phylum Mollusca Linnaeus, 1758 Gastropoda Cuvier, 1795 see Class Gastropoda Cuvier, 1795 Clade Heterobranchia Burmeister, 1837 see Superorder Heterobranchia Burmeister, 1837 Informal Group "Lower Heterobranchia" Superfamily Pyramidelloidea Gray, 1840 Family Murchisonellidae Casey, 1904