Kingdom Animalia Linnaeus, 1758 - animals Phylum Mollusca Linnaeus, 1758 - molluscs Subphylum Cyrtosoma Runnegar & Pojeta Jr., 1974 see Phylum Mollusca Linnaeus, 1758 Class Monoplacophora Odhner, 1940 - monoplacophorans Order †Bellerophontida Ulrich & Scofield, 1897 see Superfamily Bellerophontoidea McCoy, 1852 Genus †Plectonotus Clarke, 1899