The sea-otter, or kalan (_Enhydris lutris_), the most valuable of all the Russian fur-bearing animals, as 110 silver roubles is the average price of a single skin, is nearly related to the weasel tribe. The enormous value set upon the glossy, jet-black, soft, and thick fur of the kalan sufficiently explains how the Russian hunters have followed his traces from Kamchatka to America, and almost entirely extirpated him on many of the coasts and islands of Bering’s Sea and the Northern Pacific, where he formerly abounded. His habits very much resemble those of the seal; he haunts sea-washed rocks, lives mostly in the water, and loves to bask in the sun. His hind feet have a membrane skirting the outside of the exterior toe, like that of a goose, and the elongated form of his flexible body enables him to swim with the greatest celerity. The love of the sea-otters for their young is so great that they reckon their own lives as nothing to protect them from danger; and Steller, who had more opportunities than any other naturalist for observing their habits, affirms that, when deprived of their offspring, their grief is so strong that in less than a fortnight they waste away to skeletons. On their flight they carry their young in their mouths, or drive them along before them. If they succeed in reaching the sea, they begin to mock their baffled pursuer, and express their joy by a variety of antics. Sometimes they raise themselves upright in the water, rising and falling with the waves, or holding a fore paw over their eyes, as if to look sharply at him; or they throw themselves on their back, rubbing their breast with their fore paws; or cast their young into the water, and catch them again, like a mother playing with her infant. The sea-otter not only surpasses the fish-otter by the beauty of his fur, but also in size, as he attains a length of from three to four feet, exclusive of the tail. His food consists of small fishes, molluscs, and crustaceous animals, whose hard calcareous covering his broad grinders are well adapted to crush. Next to the sea-otter, the black fox, whose skin is of a rich and shining black or deep brown color, with the longer or exterior hairs of a silvery-white, furnishes the most costly of all the Siberian furs. The average price of a single skin amounts to 60 or 70 silver roubles, and rich amateurs will willingly pay 300 roubles, or even more, for those of first-rate quality. The skin of the Siberian red fox, which ranks next in value, is worth no more than 20 roubles; the steel-gray winter dress of the Siberian crossed fox (thus named from the black cross on his shoulders), from 10 to 12 roubles; and that of the Arctic fox, though very warm and close, no more than 6 or 8.