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 Achatinoidea Swainson, 1840
               Family Coeliaxidae Pilsbry, 1907 see Subfamily Coeliaxinae Pilsbry, 1907
                 Genus Pyrgina Greeff, 1882
                   Subgenus Thomea Girard, 1893