or sea-grass, which grows in immense submerged fields at the bottom of the tropical seas. It has been stated that some species will crawl up the shores of desert islands during the night, and clamber up the cliffs of lone and isolated rocks far out at sea, for the purpose of browsing on certain favourite plants. But some species, such as the great Loggerhead Turtle (Chelone caouana), which diffuse a rank odour, feed largely on cuttles, and other mollusca, their powerful jaws crushing even such stony shells as those of the great Strombi and Cassides, as a man would crack a nut. The robust form of the jaws in these animals, their trenchant and frequently notched or toothed edges, the mode in which the lower mandible shuts into the upper, and the great strength of the muscles which move them, manifested in the force with which they snap together,—while they remind the beholder of the beak of a bird of prey, yet constitute an instrument of far greater power, and seem to intimate that it must be something more than grass that requires an apparatus so formidable.
The flattened form of the Marine Turtles presents little resistance to the fluid in which they move, and their broad oar-like feet enable them to swim and dive with great velocity and grace. Mr. Audubon speaks of some species shooting through the element with the arrowy fleetness of a bird on the wing. Except when they come on shore to lay their eggs on the sand, or clamber on the rocks, as intimated above, to browse on herbage, the Turtles never leave the sea; they may often be seen in fair weather in the tropics, floating motionless on the calm surface of the
