The Game Birds, so called, form a very large and widely distributed group, the members of which are so well known the world over that it is hardly necessary to enter into a lengthy general description. Briefly it may be stated that they are birds with stout, compact bodies, a moderately long neck surmounted by a rather large, rounded head which is provided with a usually stout bill, the upper mandible of which is arched or vaulted and more or less overhangs the lower. The wings are rather short and rounded and are concave and fit closely to the body, while the tail is in general of moderate size, although there are notable exceptions to this, as in certain Quails, which have the tail so small as to be nearly concealed by the tail-coverts, while the other extreme is exhibited among the Pheasants, where it is very greatly elongated. The legs are of moderate length, but are always strong, for these birds are mainly terrestrial and depend much upon the legs for escaping danger; they are all four-toed.
The suborder Galli is divisible into two groups, the Peristeropodes,or Pigeon-toed fowls, so named from the fact that the hind toe is inserted on the same level as the others, and the Alectoropodes, or Cock-toed fowls, which have the hind toe inserted much above the level of the others, as in the common fowl. The first group comprises the families Megapodidce, the Megapodes, or Mound-Builders, and the Cracidce, or Curassows and Guans. The Megapodes are confined to the Austro-Malayan subregion, and as will be shown more at length, deposit their very large eggs in the sand or in heaps of decaying vegetation, while the Curassows and their allies are found only in Central and South America, and build nests and incubate their eggs in the orthodox manner, though the nest is built in trees and not on the ground, in the manner of all Alectoropodes. In both families the aftershafts of the feathers are always small, and while there are numerous structural characters which separate them, we may only mention that in the Megapodes the oil-gland at the base of the tail is naked, and in the Curassows it is tufted. The second group (Alectoropodes) comprises the majority of the members of the order, although it embraces but a single family (Phasianidoe), which is divided into four or more subfamilies as follows: the Meleagrince, or Turkeys of North and Central America; the Numidinece, or Guinea-Fowls of Africa and Madagascar; the Tetraoninoe, or Grouse, Ptarmigan, and Quails of wide distribution; and the Phasianinoe, or the Fowls, Pheasants, and Peacocks of Asia. The further differentiation of these sub-families will be presented under the several headings.