Phylum Mollusca Linnaeus, 1758 - molluscs
   Class Gastropoda Cuvier, 1795 - snails and slugs
     Subclass Divasibranchia Minichev & Starobogatov, 1975
       Order Stylommatophora Schmidt, 1855 see Infraorder Stylommatophora Schmidt, 1855
         (Helicid Sigmurethra)
           Superfamily Helixarionoidea Bourguignat, 1883, orth. inval.
             Family Helixarionidae Bourguignat, 1883, orth. inval. see Family Helicarionidae Bourguignat, 1877
               Subfamily Microcystinae Thiele, 1931
                 Genus Hiona Cooke, 1940
                   1 Subgenus Aukena Baker, 1940
                   2 Subgenus Insulorbis Baker, 1940
                   3 Subgenus Hionella Baker, 1940
                   4 Subgenus Hionarion Baker, 1940
                   5 Subgenus Minororbis Baker, 1940
                   6 Subgenus Nesocyclus Baker, 1940
                   7 Subgenus Neutra Baker, 1940
                   8 Subgenus Opara Baker, 1940
                   9 Subgenus Uapuneutra Baker, 1940