Myodes torquatus.—This species of Lemming was found in great abundance along the western shores of Smith Sound, and was traced by our explorers to the eighty-third degree of north latitude and to the extreme western point attained. On the Greenland shore it was found at Thank God Harbour by members of our Expedition, where it had previously been obtained by Dr. Bessels, and traces of it were noticed by our sledge parties who travelled along the northern shores of Greenland. There can be no doubt that the eastern migration of this animal has been across Robeson Channel and around the north coast of Greenland to Scoresby Sound on the east coast, from which locality this animal was brought by Captain Scoresby in 1822. Apparently its southern range on the west coast of Greenland is stopped by the great Humboldt glacier. This Lemming is a great wanderer: we found it on the floes of Robeson Channel at considerable distances from land, sometimes in a very exhausted state, but generally dead. Its habit of leaving the shore and wandering over the ice fully accounts for the skeleton of one of this species being found on a floe in latitude 81° 45' N., sixty miles from Spitzbergen, by Sir J.C. Ross during Parry's memorable attempt to reach the North Pole in 1827. The peculiar formation of the claws in this species is not permanent; that is to say, it is to a considerable extent seasonal. During the greater part of the year, when the ground is covered with snow, and the animal has to seek its food below the surface of the snow, the claws on the fore-feet attain a great development, and are used in burrowing through the snow. By the month of July, when large areas are bared of snow, and the Lemming, feeding on plants in the open, seeks shelter under rocks or by scratching holes in the earth, the lower portion of the nail on the fore-foot becomes obliterated, either being worn by contact against the hard earth or else gnawed off by the animal. The young have sharp-pointed claws on their fore-feet, and from an examination of a large series of adults of both sexes I find that the summer alteration in the shape of the claw is the same in both sexes. The month of March was the earliest date by which we had sufficient light to enable us to secure these animals, and at that season their coats were white on the outside, changing to slate-blue underneath. The food of this Lemming consists of vegetable substances, especially the buds of Saxifraga oppositifolia. It makes nests of grass in the snow, which we often found during
