Shell elongate, equivalve, inequilateral with a toothless hinge placed posteriorly; periostracum thick and brown, larger than the shell. Two genera, one infracontinental, one on the shelf.
Solemya Lamarck, 1818:
« Shell inequilateral, equivalve, elongated transversely, obtuse at the ends, with a shiny, overflowing epidermis. Umbos barely protruding, without projection. On each valve a cardinal tooth, dilated, compressed, very oblique, slightly concave above, receiving the ligament. Ligament partly internal and partly external. » – J.-B. M. de Lamarck: Histoire naturelle des animaux sans vertèbres vol.V, Paris 1818, p.488.
