Phylum Mollusca Linnaeus, 1758 - molluscs Conchifera Gegenbaur, 1878 see Subphylum Conchifera Gegenbauer, 1878 Cyrtosoma Class Cephalopoda Cuvier, 1795 - cephalopods Nautiloidea Agassiz, 1848 see Subclass Nautiloidea Agassiz, 1848