PINNIPEDIA, a suborder of Carnivore, the seals, especially adapted in the structure of their links to an aquatic existence, as the name indicates. Both pairs of limbs, and especially their proximal segments, ; re very short, and the distal part flattened, webbed and paddle-like. The hind limbs are placed very far back and are very peculiar in that the first and fifth toes are stout and as long or longer, instead of shorter, than the others. The head is usually short and rounded, the neck short, the trunk thick and fusiform and the tail rudimentary. The teeth are simpler in structure than in most carnivora, the molars and premolars being either nearly simple cones or crowned with numerous small-pointed tubercles; the incisors are re duced in size and often in number, but the canines of the males are usually enlarged, and in the walruses become enormous tusks. The brain is large and much convoluted, and the eyes large and possessed of a very human ex pression. All of the pinnipeds spend the greater Part of their fives in the water, swimming with great speed and dexterity; but the peculiar structure of their limbs ill adapts them for ter restrial progression, which is accomplished in an awkward shuffling manner with severe con tortions of the back. They are chiefly marine,
frequenting the coasts of colder climates, though some species are tropical and others enter fresh water. Some of the species spend much time far out at sea, but land on islands for the purpose of mating and bearing young. Most of them are carnivorous, feeding upon fishes, mollusks and crustaceans, but a few subsist in part upon marine alga:. The pinni pedia have been derived. from land animals, probably from the bears, and their adaptation to an aquatic habitat is not nearly so extreme as in the whales. Three families are usually recognized: The Otaride, or eared seals, which have a small, valvular, external ear and include the sea-lions and sea-bears. The Phocida. have no external ear, and are the most completely aquatic members of the suborder. Here belong the common harbor-seal of the north Atlantic coast, the hooded seal, the sea-elephant and numerous other species. In the Trichechide is included only the walrus, in many respects the most remarkable of the entire group. Consult Allen, J. A., 'History of North American Pin pipeds) (1880). See SEALS; ELEPHANT-SEAL; WALRUS.