In the waters of Novaia Zemlaia, Greenland, and Spitzbergen is found the narwhal, or sea unicorn (_Monodon monoceros_), which was at one time the theme of so many extravagant legends. It belongs to the Cetacea, but differs from the whale in having no teeth, properly so called, and in being armed with a formidable horn, projecting straight forward from the upper jaw, in a direct line with the body. This horn, or tusk, the use of which has not been satisfactorily ascertained, is harder and whiter than ivory, spirally striated from base to point, tapers throughout, and measures from six to ten feet in length. Mr. Bell remarks that it would be a strange anomaly if the apparent singleness of this weapon were real. In truth, _both_ teeth are invariably found in the jaw, not only of the male, but of the female also; but in ordinary (though not in all) cases one only, and this in the male, is fully developed, the other remaining in a rudimentary condition--even as both do in the female. [Illustration: NARWHALS, MALE AND FEMALE.] The narwhal, from mouth to tail, is about twenty feet long, though individuals measuring thirty feet are sometimes met with. Its head is short, and the upper part convex; its mouth small; its spiracle, or respiratory vent, duplicate within; its tongue long; the pectoral fins small. The back, which is convex and rather wide, has no fins, and sharpens gradually towards the tail, which, as in other Cetacea, is horizontal. The food of the narwhal, whose habits are remarkably pacific, consists of medusæ, the smaller kinds of flat fish, and other marine animals. * * * * * A striking spectacle which frequently greets the eye of the voyager in the Arctic seas is that of a shoal of dolphins gambolling and leaping, as if in the very heyday of enjoyment. The beluga, sometimes called the white whale (_Delphinus leucos_), attracts attention by the dazzling whiteness of its body and the swiftness of its movements. It frequents the estuaries of the Obi and the Irtish, the Mackenzie and the Coppermine, which it sometimes ascends to a considerable distance in pursuit of the salmon. Its length varies from twelve to twenty feet; it has no dorsal fin; and its head is round, with a broad truncated snout. [Illustration: A SHOAL OF DOLPHINS.]