usually differ in the coloration of their plumage; the young at first resemble the mother, but very soon attain their adult garb. The _Pteroclæ_ are only met with in the Eastern Hemisphere, and are particularly numerous in Africa, whilst in Europe, owing to the small extent of their favourite barren tracts, they are comparatively rare. Africa and Asia have their distinct species, which usually remain throughout the entire year in their native lands; owing, however, to their great power of wing, they are capable of flying to a considerable distance, and often make their appearance in countries very remote from each other. One species alone migrates annually. THE GANGA, OR LARGE SAND GROUSE. The GANGA, or LARGE SAND GROUSE (_Pterocles arenarius_), one of the largest members of the group, is of a reddish grey on the head, shading into a somewhat deeper tint at the nape; the mantle is mottled with light or dark yellow and slate-grey, each feather having a round yellow spot at its tip; the throat is ochre-yellow, a band upon its lower portion brownish black; the breast is reddish grey, and has a very clearly defined streak on its surface, which is black or brownish black, as is the belly; the quills are grey or greyish blue, tipped with brownish black above and deep black beneath; the secondaries are white at the roots; some of the feathers on the upper wing-covers are partially of a pure, unspotted ochre-yellow, and those of the lower covers white; the two centre tail-feathers are reddish brown, striped with pale black; the rest are deep grey, tipped with white above, and coal-black on their lower surface. The feathers on the upper tail-covers are mottled like the back, and those on the lower covers spotted black and white; the plumage on the feet is of a dark brownish yellow. The eye is deep brown, the beak dull blueish grey. Both sexes are about thirteen and a half inches long, and from twenty-six to twenty-seven inches broad; the wing measures eight inches and three-quarters, and the tail four inches. The female is of a sandy yellow over the entire back and sides of the throat, each of the mantle feathers being striped with blackish brown, and those on the head, neck, throat, and upper breast marked with small dark spots: the bands upon the throat and breast are comparatively indistinct, and the brown and black belly paler than that of the male bird.