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 Oleacinoidea H. Adams & A. Adams, 1855
               Family Spiraxidae Baker, 1939
                 Subfamily Spiraxinae Baker, 1939
                   Genus Pseudosubulina Strebel & Pfeffer, 1882
                     1 Subgenus Tornaxis Martens, 1898