Bovidae, a family of even-toed ruminants, here used as the equivalent of Cavicornia or Hollow-Horned Ruminants. The term Bovidae has had various definitions, but in this sense embraces oxen, bisons, buffaloes, antelopes, sheep and goats, though these animals have been classed in three, and sometimes in as many as five different families. Many of the members of this group are widely dissimilar in external appearance, but the annectant forms are so numerous, and grade into each other by such imperceptible degrees, that it was found impracticable to frame satisfactory definitions for the smaller groups adopted by some naturalists. For this reason the larger definition of the family is the more general one, the antelopes, oxen, sheep and goats being considered as groups, each of which has too much in common with the others to be entitled to the rank of a family. In the Bovidae are included the typical ruminants, and those of most service to man for food, for beasts of burden and for the commercial importance of their skins, bones, horns, etc. There are six molar teeth on each side in each jaw; six incisors and two canines in the lower jaw, separated by a wide interval from the molars, and in the forepart of the upper jaw there is a horny pad, against which the incisors and canines of the lower jaw bite. The frontal appendages differ widely from those of the deer, and consist of horn-cores (processes of the frontal bone), covered with a sheath of horn, never shed except by the American Prong-horn (q.v.). Generally speaking, horns are present in both sexes, sometimes, however, only in the males. The feet are cleft, and there are generally accessory hoofs. The family is chiefly confined to the Old World, only a few forms being found in America.