Phylum Mollusca Linnaeus, 1758 - molluscs
   Class Bivalvia Linnaeus, 1758 - bivalves
     Subclass Heterodonta Neumayr, 1884 see Clade Heterodonta Neumayr, 1884
       Order Myida Stoliczka, 1870
         Suborder Myina Stoliczka, 1870 see Superfamily Myoidea Lamarck, 1809
           Superfamily Myoidea Lamarck, 1809
             Family Myidae Lamarck, 1809 - soft-shelled clams
               Subfamily Myinae Lamarck, 1809
                 Genus Tugonia Gray, 1842
                   Subgenus Distugonia Iredale, 1936