This term applies to hares and rabbits, both belonging to the order Rodentia, or gnawing animals, and included in the family Leporidae (hare kind), which is distinguished by its members possessing two small incisors in the upper jaw in addition to the two ordinary incisors, thus making four incisors in the upper and two in the lower jaw, whilst no canines exist in either jaw. The pro-molars number six in the upper and four in the lower jaw, and the molars exist to the number of six in each jaw. The latter two kinds of teeth are destitute of roots, and the clavicles or collar bones are of a rudimentary nature. The front feet possess five and the hinder four toes, and the hind legs exceed the fore-limbs in length. The tail is short and erect, and the two orbits or eye cavities of the skull communicate by an aperture in the septum or partition which divides them. The hare possesses a redder fur than the rabbit and greater length of ears, which are tipped with black. The hind legs in the hare are proportionately longer than in the rabbit, and the eyes are larger and more prominent. The rabbit differs from the hare by its generally smaller size, by the shorter ears of uniform brown colour, and by the shorter limbs.

The rabbit seems to have no social feeling for the hare, and it rarely happens that a hybrid progeny of the two species is produced. In such cases, with one or two exceptions, the father of the hybrids has invariably been a rabbit and the mother a hare.