Phylum Mollusca Linnaeus, 1758 - molluscs Conchifera Gegenbaur, 1878 see Subphylum Conchifera Gegenbauer, 1878 Cyrtosoma Class Gastropoda Cuvier, 1795 - snails and slugs Subclass †Archaeobranchia Parkhaev, 2001 Order †Pelagielliformes Runnegar & Pojeta, 1985 Family †Aldanellidae Linsley & Kier, 1984 Genus †Nomgoliella Missarzhevskij, 1981