Shell solid, strongly inequivalve. Almost equilateral; beaks close to midline. Outline quadrate, length almost equal to height; posterior margin straight, anterior and ventral margins curved. Sculpture of 27-30 wide, smooth radial ribs with interspaces a little narrower than ribs. Taxodont hinge with numerous teeth on a thin hinge plate in a straight line. Ligament with few distinct chevrons. Internal margin strongly crenulate. Periostracum of fine lamellae.
dirty white with brown periostracum.
common size :
shell to 50 mm.
Differs from S. inflata (Reeve, 1844), a Red Sea species in size, shape and number of ribs: S. inflata shell up to 150 mm, rounded in profile and with 37 ribs.
BIOLOGY / ECOLOGY
infralittoral zone, in sandy muds and muds in shallow waters (Oliver, 1992). In the Mediterranean shells dredged from 55 m (Barash and Danin, 1973).