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 Orthalicoidea Martens, 1860
               Family Orthalicidae Martens, 1860
                 Subfamily Bulimulinae Tryon, 1867
                   Genus Placostylus Beck, 1837
                     Subgenus Maoristylus Haas, 1935