Phylum Mollusca Linnaeus, 1758 - molluscs Class Monoplacophora Odhner, 1940 [monotypic] - monoplacophorans Order Monoplacophorida Wenz, in Knight, 1952 Superfamily Trybliidioidea Millard, 1997, orth. inval. see Superfamily Tryblidioidea Pilsbry, 1899 Family Vemidae Moskalev et al., 1983 [monotypic] 1 Genus Vema Clarke & Menzies, 1959