Phylum Mollusca Linnaeus, 1758 - molluscs Class Bivalvia Linnaeus, 1758 - bivalves Subclass Palaeoheterodonta Newell, 1965 see Clade Palaeoheterodonta Newell, 1965 Order Unionida Gray, 1854 Superfamily Muteloidea Gray, 1847 see Superfamily Etherioidea Deshayes, 1832 Family Etheriidae Deshayes, 1832 - freshwater oysters Genus Etheria Lamarck, 1807