There are three families of the Sea Carnivora,—the Fur-seals, or Eared Seals; the Walrus; and the True or Earless Seals.
Photo by G. W. Wilson & Co., Ltd.] [Aberdeen.
STELLER'S SEA-LION.
The eared seal, or sea-lion, has the hind flippers divided, and is thus able to move with comparative ease on land.
The first group, which are called Eared Seals, and occasionally Sea-lions and Sea-bears, have a small outer ear, and when on land the hind flippers are folded forwards beneath the body. There is a distinct neck, and on the flippers are rudimentary claws. Some of the eared seals have the close and fine under-fur which makes their capture so remunerative. Under the skin there is often a thick layer of blubber, which is also turned to commercial uses by the sealers.
The Walrus stands by itself. It is a purely Arctic species, whereas fur-seals are found from Bering Sea to the Antarctic; and forms in some degree a connecting-link between the eared seals and the true seals. Like the former, it turns the front flippers forwards and inwards when on land; but it resembles the true seals in having no external ears. The upper canine teeth are developed into enormous tusks of hard ivory.
The Common Seals are the most thoroughly aquatic. The hind flippers seem almost to have coalesced with the tail, and are always directed backwards in line with it. They have no under-fur. On land they can only use the front flippers to aid their progress.
Most seals are marine, though some are found in the land-locked sea of Lake Baikal, in Central Asia, and the true seals often come up rivers.
The Eared Seals, or Sea-lions.