[Kingdom] Animalia Linnaeus, 1758 - animals Grade Enterozoa Grade Cœlomata Phylum Mollusca Linnaeus, 1758 - molluscs Branch Eucephala Grade Echinoglossa Class Gastropoda Cuvier, 1795 - snails and slugs Grade Amphomœa Order Polyplacophora Gray, 1821 1 Genus Chiton Linnaeus, 1758 2 Genus Chitonellus Lamarck, 1819 see Genus Cryptoplax Blainville, 1818