Large, and rather heavy; wings long; tarsi feathered, a narrow space naked behind; toes naked, and rather short. Adult. Entire plumage glossy black, in many specimens with a brown tinge; forehead, throat, and a large space on the head behind, mixed with white. Tail with one well-defined band of white, and irregularly marked towards the base with the same color. Quills with their inner webs white, most readily seen on the under-surface of the wing. Some specimens have several well-defined bands of white in the tail. Others have the entire plumage dark chocolate-brown, with the head more or less striped with yellowish-white and reddish-yellow. Cere and legs yellow. Younger. Upper-parts light umber-brown, with the feathers more or less edged with yellowish-white and reddish-yellow; abdomen with a broad transverse band of brownish-black; other under-parts pale yellowish-white, longitudinally striped on the neck and breast with brownish-black; wings and tail brown, tinged with cinereous; quills for the greater part of their length white on their inner webs; tail-feathers white at their bases. Plumage of the tibiæ and tarsi pale reddish-yellow, spotted with brown. Other specimens have the throat and breast with the black color predominating. Young male? Entire upper-parts light ashy-brown, more or less mixed with white, especially on the head and fulvous; under-parts yellowish white and dark-brown, the latter assuming the form of longitudinal stripes on the breast, and narrow transverse stripes on the abdomen; tarsi and tibiæ dark-brown, striped with dull-white and reddish; greater part of quills and tail white. Cere and legs yellow. Dimensions. Total length, _female_, 22 to 24 inches; wing, 17 to 17½; tail, 9 inches. _Male_—total length, about 20 to 21 inches; wing, 16 to 16½; tail, 8 to 8½ inches. Hab. Entire North America; Oregon (Townsend). Spec. in Mus. Acad. Philada. Obs. This is one of the most abundant of the birds of this family, in all the States on the Atlantic, and is one of the most variable in plumage. Two stages of plumage—the adult black bird and the young, when the wide abdominal band of black is well defined—are easily recognized; but there are a variety of other plumages which are difficult to refer to their proper age, sex, or season. Although the stage of plumage described above as perhaps that of the young male (figured by Wilson, pl. 53, fig. 2, and Aud., pl. 422, fig. 2) may be correct, we regard it as by no means established, and in fact are inclined to suspect that there are two distinct species confounded. 2. Archibuteo lagopus. (Gm.) The Rough-legged Buzzard. Falco lagopus. Gmelin, Syst. Nat., I. p. 260. (1788.) Wils., Am. Orn., IV. pl. 33, fig. 1; Aud., B. of Am., pl. 166; Gould, B. of Eur., I. pl. 15.