In many respects the Pikas closely resemble the Hares, but they are distinguished by having only five molars on each side in each jaw, a depressed skull, with contracted frontal bones destitute of the wing-like process seen in the Hares, complete clavicles, short ears, limbs nearly equal in length, and no tail visible externally. They are much smaller than any of the Leporidæ, the largest being no larger than a Guinea-pig, to which the animals have some resemblance; while in their habits they somewhat resemble the Marmots. When feeding they often produce a chirping or whistling noise, whence the name of Piping Hares, or Calling Hares, has been applied to them. Ten or a dozen supposed species of these animals have been described, most of them inhabiting the northern and mountainous parts of Asia, and one of these is also found in Europe, about the southern part of the Volga. In Asia species have been found as far south as the Himalayas and Nepaul. In North America a single species (_Lagomys princeps_) inhabits the Rocky Mountains, where it was first discovered by Sir John Richardson. The ALPINE PIKA (_Lagomys alpinus_), which inhabits Siberia from the Irtish eastwards into Kamtchatka, is a little animal from nine to nine and a half inches long, of a greyish-brown colour above, yellowish-grey beneath; the feet are pale, and the ears dirty yellowish-white within, becoming dusky towards the margin, which is white. This animal occurs in considerable numbers in the Alpine and sub-Alpine parts of Siberia, where it either burrows in the ground, or shelters itself in crevices of rocks or among loose stones. The Pikas generally come out only at night, although they sometimes venture forth on a cloudy day. Their food consists of the scanty herbage to be found in their elevated abode, and as this would be impossible to procure during the winter when the ground is thickly covered with snow, the Pikas take care in the autumn to collect a large supply of dried grasses and other herbage, which they pile up near their habitations like little haystacks. They are, however, sometimes deprived of the fruits of their labour by the Sable-hunters, who plunder the Pikas’ stacks to feed their Horses. The female produces about six naked young early in the summer. [Illustration: ALPINE PIKA.]