Members of this family have rounded or oval, elongated shells, much flattened. The two valves are connected by an internal ligament in contrast to the closely related family
Tellinidae where the ligament is external. The two separate siphons are very long, sometimes several times the length of the shell. These siphons have a characteristic cruciform muscle at their base.[1]
Selected genera
Genera of Semelidae (with some notable species also listed) include:[2]