The most remarkable character in this species consists in the great length of the fur,—the longer hairs on the back measuring upwards of three inches, and those on the hinder part of the back, are from four and a half, to four and three quarter inches in length. The general colour of the fur is pale yellow-gray. Numerous irregular yellow, or sometimes brown stripes run in an oblique manner from the back along the sides of the body. On each side of the face there are two stripes of a yellowish or cinnamon colour: these stripes commence near the eye, extend backwards and downwards over the cheeks, on the hinder part of which they join and form a single line, which encircles the lower part of the throat. The tip of the muzzle and the chin are white, and there is a spot in front of the eye, and a line beneath the eye, of the same colour: the belly and the inner side and hinder part of the fore legs are also white. An irregular black line runs across the lower part of the chest and extends over the base of the fore legs externally, and above this line there are two other transverse dark markings on the chest, which are more or less defined. On the fore legs there are three broad black bands, two of which encircle the leg, and on the posterior legs there are about five black bands externally, and some irregular dark spots internally. The feet are yellowish, and the underside of the tarsus is of a slightly deeper hue. On the belly there are numerous large irregular black spots. The ears are of moderate size, furnished internally with long white hairs; externally, the ears are of the same colour as the head, excepting at the apex where the hairs are black and form a slight tuft. The tail is short, somewhat bushy, and devoid of dark rings or spots—the hairs are in fact coloured as those of the back of the animal. On the upper part of the body each hair is brown at the base, then yellow, and at the apex, black. On the hinder part of the back the hairs are almost black at the base, and on the sides of the body each hair is gray at the base; there is then a considerable space of yellowish white colour; towards the apex they are white, and at the apex black. The greater number of the hairs of the moustaches are white. In. Lines. Length from nose to root of tail 26 0 to base of ear 3 6 of tail (fur included) 11 0 of ear 1 11 Height of body at shoulders 13 0 Habitat, Santa Cruz, Patagonia, (_April_,) and Bahia Blanca, (_August_).