To North America belongs the Gray Squirrel (_Sciurus Carolinensis_), where he enjoys his free and sportive life in the great forests of hickory, oak, maple, and chestnut. His whole length, including the tail, is about two feet. As he forays plentifully among the corn-fields, the inhabitants regard him as a scourge, and wage deadly war against him. Like the lemming, he migrates about autumn, in immense hosts; advancing in a straight course, which no obstacle is permitted to interrupt, and spreading desolation, like the course of an invading army. The large species of the Fox Squirrel (_Sciurus vulpinus_) belongs exclusively to the "murmurous pine-woods" of South America. The Cat Squirrel (_Sciurus cinereus_) is remarkable for the exquisite fineness of his fur. In the neighbourhood of Hudson's Bay dwells the Red or Hudson's Bay Squirrel (_Sciurus Hudsonius_), marked along the middle of the back by a ferruginous line from head to tail, with the belly of a pale ash-colour, mottled with black. In the northern districts of Africa we meet with the Barbary Squirrel (_Sciurus getulus_), which dwells among the palm-trees, and is of a grayish-brown colour, lightly shaded with red, with two white longitudinal bands separated by a brown streak. Cross to the eastern coast, and there we find the Abyssinian Squirrel, which has a greenish-gray back, white belly, and tail ringed with black and white; on the western side, the Ivory-eating Squirrel, which nibbles the tusks of elephants killed by hunters; and the Kendo Squirrel, one of the smallest known. The two latter species were discovered and specified by M. Du Chaillu, who has named the former _Sciurus eborivorus_, and the latter _Sciurus minutus_. Among the Indian Squirrels I may name the great Malabar Squirrel (_Sciurus maximus_), less remarkable for his size, which is more than double that of the European Squirrel, than for the variety and vivacity of his colours. On the upper part of the head, the flanks, and thighs are of a chestnut purple; the shoulders, hind-quarters, and tail of a glossy black; the belly and inner sides of the limbs, a pale yellow. Zoologists have classified in two genera, distinct from the true Squirrels, under the names of _Pteromys_ and _Sciuroptera_, the animals popularly called "Flying Squirrels." The first of these genera is proper to Southern Asia; the second comprehends the species common to Asia and Eastern Europe, others which are exclusively Asiatic, and others which are only met with in North America.