The pectoral fins were small and were placed low down on the sides. Their anterior base was as far removed from the eye (in a straight line) as the eye was from the extremity of the beak. Their shape was somewhat different from that of the flippers of _M. bidens_ figured by Sir William Turner.[27] Their anterior margin was nearly straight throughout; the extremity was evenly and distinctly rounded off. The posterior margin was slightly convex in the distal half and straight proximally. The conformation of the region of the axilla was quite peculiar. The hard integument of the posterior margin of the flipper was continued proximally inward and forward to a point near the head of the humerus. The triangular area between this stiff edge and the side of the body was occupied by a thin, soft, wrinkled skin, in the middle of which the olecranon could be felt. On the side of the body this soft integument occupied an area nearly as large as the flipper, the underlying thick layer of blubber ending abruptly, especially below. A depression was thus formed in which the flippers could be placed so as to be almost in the same general plane with surrounding surfaces of the body. They are probably so placed when the animal is swimming. The flukes had the general lunate form common to all species of the order. The posterior margin is not divided in the center. Its middle third was convex; its lateral thirds concave. In these and other respects the shape of the flukes agreed closely with Sir William Turner’s excellent figure of _M. bidens_.[28] The antero-posterior breadth of the flukes was, however, somewhat greater in proportion to their transverse breadth than is indicated in this figure. The caudal peduncle terminated above at a point 6½ inches in front of the posterior margin of the flukes. On this margin were situated three star-shaped white scars, which appeared to mark the points of attachment of crustacean parasites. The margins of the upper jaw were very obtuse posteriorly, the rostrum being covered with a layer of blubber of gradually increasing thickness. A depression bounded by gradually converging lines extended 4¼ inches back of the angle of the mouth. The inferior surface of the bony palate extended below the level of the lips, and the sides of the former were visible upon looking into the mouth laterally. The blowhole was large and somewhat unsymmetrically placed, the right angle being the more anterior. The concavity was forward. The eye was situated a little below the line of the mouth and 20¼ inches from the extremity of the snout. The external opening of the ear was 2⅞ inches behind the posterior angle of the eye, and a little below the line of the lower eyelid. The two throat-furrows were of unequal length. The left furrow was 6¾ inches long, and its anterior end was distant 8⅝ inches from the extremity of the jaw. The right furrow did not extend quite so far forward, and was 7⅜ inches long.