Bifid, opening with a cleft.
Bilobate, divided into two lobes.
Bimarginate, two margins or lips.
Biradiate, having two rays.
Bivalve, having two valves.
Blunt, obtuse, opposed to acute.
Borer, a piercer.
Bulging, gibbous, swollen out.
Byssus, common in the Mytilus and Pinna, by which they attach themselves to objects.
C.