The _Columbian Pine Squirrel_ was seen by Lewis and Clarke on the banks of the Columbia river, but is supposed by Richardson to be a variety of the Hudson’s Bay Squirrel, its habits being similar. The _Common Red Squirrel_ is abundant in most parts of North America. It is one of the most lively and nimble of the squirrel race. It digs burrows at the roots of large trees, to which it forms four or five entrances. It does not leave its tree in cold and stormy weather, but when it is sporting in the sunshine, if any one approaches, it conceals itself, and makes a loud noise, similar to a watchman’s rattle. From this circumstance it has received the name of Chickaree. When pursued, it makes long leaps from tree to tree, and seeks for shelter as soon as possible in its burrow. The skin of this animal is of no value. It is of a reddish brown color, shaded with black. The tail is long and beautiful. The _Ground_ or _Striped Squirrel_ is abundant in all our woods. It is sometimes called Harkee, and, in New England, is usually denominated the Chip Squirrel. It differs very much from other squirrels in its habits. It never makes its nest in the branches of trees, but burrows in the ground near the roots. These burrows extend a considerable distance under ground, and are always provided with two openings. The general color of this animal is of a reddish brown. The _Common Flying Squirrel_[47] is very abundant in the United States, and is much admired for the softness of its fur, and the gentleness of its disposition. The skin of the sides is extended from the fore to the hind limbs, so as to form a sort of sail, which enables it to descend swiftly from a great height, in the easiest and most pleasant manner, often passing over a considerable space. This squirrel is small, of an ash color above, and white beneath, with large, prominent black eyes. It builds its nest in hollow trees. The _Rocky Mountain Flying Squirrel_ lives in thick pine forests, and seldom leaves its retreats except at night.