Phylum Mollusca Linnaeus, 1758 - molluscs
   Class Bivalvia Linnaeus, 1758 - bivalves
     Subclass Heterodonta Neumayr, 1884 see Clade Heterodonta Neumayr, 1884
       Order Chamida see Order Venerida Gray, 1854
         Superfamily Cardioidea Lamarck, 1809
           Family Cardiidae Lamarck, 1809 - cockles
             Subfamily Protocardiinae Reuss, 1846
               Genus Nemocardium Meek, 1876
                 1 Subgenus Nemocardium Meek, 1876
                 2 Subgenus Frigidocardium Habe, 1951
                 3 Subgenus Keenaea Habe, 1951
                 4 Subgenus Lophocardium Fischer, 1887
                 5 Subgenus Microcardium Thiele, 1934
                 6 Subgenus Pratulum Iredale, 1924
                 7 Subgenus Discors Deshayes, 1858
                 8 Subgenus Habecardium Glibert & van de Poel, 1970