Members of this family have inequivalve, oblong valves that are nearly equilateral. The right valve is more convex than the left and there are usually no teeth. The ligament connecting the two valves is in an internal groove and the hinge has a free ossicle.
[2]
Genera and species
The World Register of Marine Species lists the following genera and species in the family:[1]
^Gordon, W. J. Our Country's Shells: A Guide to the British Mollusca. London: Simpkin, Marshall, Hamilton, Kent & Co. {{cite book}}: Cite has empty unknown parameter: |coauthors= (help)