Phylum Mollusca Linnaeus, 1758 - molluscs
   Class Gastropoda Cuvier, 1795 - snails and slugs
     Subclass Heterobranchia Burmeister, 1837 [monotypic] see Superorder Heterobranchia Burmeister, 1837
       Order Heterostropha Fischer, 1885
         Superfamily Valvatoidea Gray, 1840
           Family Orbitestellidae Iredale, 1917
             1 Genus Orbitestella Iredale, 1917
             2 Genus Microdiscula Thiele, 1912
             3 Genus Helisalia Laseron, 1954
             4 Genus Microcarina Laseron, 1954
             5 Genus Boschitestella Moolenbeek, 1994
             6 Genus Zalipais Iredale, 1915