Phylum Mollusca Linnaeus, 1758 - molluscs Class Bivalvia Linnaeus, 1758 - bivalves Subclass Protobranchia Pelseneer, 1889 Order Solemyida Dall, 1889 Superfamily Solemyoidea Gray, 1840 [monotypic] Family Solemyidae Gray, 1840 - awning clams Genus Solemya Lamarck, 1818 Subgenus Petrasma Dall, 1908