living organisms see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Superkingdom Eukaryotae see Domain Eukaryota Chatton, 1925
     Kingdom Animalia Linnaeus, 1758 - animals
       Subkingdom Eumetazoa Butschli, 1910 see [unranked] Eumetazoa Bütschli, 1910
         Phylum Mollusca Linnaeus, 1758 - molluscs
           Class Gastropoda Cuvier, 1795 - snails and slugs
             Subclass Opisthobranchia Milne-Edwards, 1848 - opisthobranchs see Order Opisthobranchia Milne-Edwards, 1848
               Order Sacoglossa Ihering, 1876 - sacoglossans
                 1 Family Cylindrobullidae Thiele, 1931
                 2 Family Volvatellidae Pilsbry, 1895
                 3 Family Juliidae Smith, 1885
                 4 Family Oxynoidae Stoliczka, 1868 (1847)
                 5 Family Caliphyllidae Tiberi, 1881
                 6 Family Stiligeridae Iredale & O'Donoghue, 1923 see Family Limapontiidae Gray, 1847
                 7 Family Elysiidae Forbes & Hanley, 1851 see Family Placobranchidae Gray, 1840, orth. inval.