Plate 3.
Page 10.
TERMS—
UNIVALVES.
"Ears are two processes on each side of the beak; the Pecten, or scallop, is an example. ([Plate 3], i.)
"Sinus, in bivalve shells, is a small hollow in the hinge.
"Byssus, or beard, is an appendage composed of silky threads, by which the muscle and Pinna fasten themselves to the rocks. ([Plate 3], f.)
"Cordiform is a term applied to heart-shaped shells.
"A cartilage is the same as a ligament. When the valves of a shell are very nearly flat, they are said to be compressed: when a valve has teeth, it is said to be dentated.