Angel Wing (Cyrtopleura costata)
(up to about 7 in.)
Angel wings are found along the East Coast from Massachusetts southward.
A bivalve with a fragile, white shell covered with a thin, yellow-tinted periostracum, the angel wing burrows in sand or mud up to two feet deep and feeds on algae through a siphon.
The angel wing has no ligaments to keep the shell closed: because it rocks itself into a tight-fitting burrow, the adductor muscles are enough to see that the shell remains closed.