The head is rather short and rounded; the fore limbs or paddles are small and broad compared with those of most dolphins; and (as in the beluga) a dorsal fin, found in nearly all other members of the group, is wanting.
Meerschwein, although the word is commonly used by sailors to designate all the smaller cetaceans, especially those numerous species which naturalists call "dolphins," it is properly restricted to the common porpoise of the British' seas (Phocaena communis, or P. phocaena).
The head is rounded in front, and differs from that of dolphins in not having the snout produced into a distinct "beak" separated from the forehead by a groove.
A day-flying bat, whales and dolphins are about the only indigenous mammals; hogs, dogs and rats had been introduced before Cook's discovery.
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