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
         (Achatinid Sigmurethra)
           Suborder Sigmurethra Pilsbry, 1900 see Group Sigmurethra Pilsbry, 1900
             Superfamily Rhytidoidea Pilsbry, 1893
               Family Systrophiidae Thiele, 1926 see Subfamily Scolodontinae Baker, 1925
                 Genus Happia Bourguignat, 1889
                   Subgenus Happiella Baker, 1925