Phylum Mollusca Linnaeus, 1758 - molluscs Conchifera Gegenbaur, 1878 see Subphylum Conchifera Gegenbauer, 1878 Cyrtosoma Class Gastropoda Cuvier, 1795 - snails and slugs Orthogastropoda Ponder & Lindberg, 1995 see Subclass Orthogastropoda Ponder & Lindberg, 1995 Apogastropoda Salvini-Plawen & Haszprunar, 1987 Heterobranchia Burmeister, 1837 see Superorder Heterobranchia Burmeister, 1837