| Ft. | in. | |
|---|---|---|
| Total length (in a straight line) | 12 | 6 |
| Tip of beak to base of dorsal fin (along the back) | 7 | 6½ |
| Tip of beak to base of pectoral fin (along the back) | 2 | 11 |
| Length of pectoral fin along center | 11 | |
| Greatest breadth of pectoral fin | 3¾ | |
| Height of dorsal fin (in a straight line) | 6 | |
| Length of base of dorsal fin | 1 | 2 |
| Breadth of flukes (tip to tip) | 2 | 11 |
| Depth of tail 14 inches in front of posterior margin of flukes | 8¼ | |
| Tip of beak to angle of mouth | 9¾ | |
| Tip of beak to eye | 1 | 8¼ |
| Length of eye | 1 | |
| Breadth of blowhole | 4 | |
| Tip of beak to right angle of blowhole | 1 | 6½ |
EXTERNAL FORM AND COLOR.
The general form was slender and elongate. The beak sloped gradually from its extremity to the forehead, and there was no constriction separating the beak from the remainder of the head. Behind the blowhole, the outline of the back commenced at a higher level, but immediately curved slightly downward, indicating the position of the neck. The line then rose gradually until the anterior base of the dorsal fin was reached. Behind the fin the outline sloped downward gradually to the flukes.
The dorsal fin was relatively small, falcate, and obtusely terminated. The distance in front of its anterior base was three-fifths of the total length. Its posterior margin was continuous with the ridge of the back, which extended to the flukes and terminated abruptly a little anterior to the middle point of the antero-posterior breadth of the flukes. In front of the fin the back was rounded.
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.