(Linné, 1758)
Description (shell);
Shell is solid, equivalve and almost equilateral; beaks are about the midline and directed inwards and slightly forwards. Outline is approximately circular in outline but tending to be a little deeper than long. Ligament is deeply inset extending beneath and across the valves. Lunule is small. Sculpture of lines diverging from the centre of the shell to the margins; concentric lines also present. Growth lines are clear. Right valve with one conspicuous cardinal tooth and two small laterals; left valve with two cardinals and two anterior and two posterior laterals. Adductor muscle scars are about equal. The shell margin is crenulate.
Size:
Up to 12.7 mm in length.
Colour:
Outside and inside of shell are white (L. divaricata). Periostracum is slight.
Distribution:
Found in the German Bight (Distr. L. divaricata). Distributed south the Mediterranean and Black Sea, and to Madeira and Canary Isles.