Page:Natural History (1848).djvu/104

94 pelvis, tapers almost to a point; the broad web-bed feet; the spongy lightness of the bones; and the short, close fur lying flat upon the skin, admirably adapt this Family for their ocean-life. They shoot through the water with almost the rapidity of fishes.

The physiognomy of the Seals is generally pleasing; the head is round, the muzzle short and fleshy; the eyes are large and dark, with a mild expression. The external ears are either very small, or altogether wanting; their orifices as well as those of the nostrils can be closed by muscular effort at the will of the animal. The Seals are scattered over the margins of all seas; but are most numerous in the Arctic and Antarctic oceans, where they constitute an object of commercial pursuit, from the value of their fur and their abundant surface-fat, which is melted into oil.

The teeth of the common Seals are thus arranged; inc. $6⁄4$; can. $1—=1⁄1—1$; mol. $5—5⁄5—5$:=34. They are evidently formed, observes Mr. Bell, “for the purpose of seizing, holding, and partially dividing the scaly and slippery fish upon which the Seal feeds; the canines are strong, but acute; the molars beset with points of various size and form, but all adapted to their piscivorous habits; and the simple stomach is in perfect harmony with such a structure.” The form of the skull is flattened on the top, swelling at the sides; it has only slight roughnesses in the place of occipital crests. There are no visible ears.