Black Hawk, Falco niger, Wils. Amer. Orn. v. vi. p. 82. Adult. Falco lagopus, Bonap. Syn. p. 32. Young. Falco Sanci-Johannis, Bonap. Syn. p. 32. Adult. Buteo lagopus, Rough-legged Buzzard, Swains. & Rich. F. Bor. Amer. v. ii. p. 52. Rough-legged Falcon, Falco lagopus, Wils. Amer. Orn. v. iv. p. 59, Young; v. v. p. 216, Adult and Young. GENUS III. AQUILA, Briss. EAGLE. Bill rather short, deep, compressed; upper mandible with the dorsal outline nearly straight and sloping at the base, beyond the cere decurved, the sides sloping and slightly convex, the edges nearly straight, with a slight convexity and a shallow sinus close to the strong subtrigonal tip; lower mandible with the dorsal outline convex, the tip obliquely truncate. Head large, roundish, flattened above. Nostrils oval, oblique, nearer the ridge than the margin. Neck rather short. Body very large. Feet rather short, very robust; tarsi roundish, feathered to the toes; which are rather short, united at the base by short webs, covered above with a series of angular scales, and towards the end with a few large scutella; claws long, curved, rounded, flat beneath, acuminate. Plumage compact, imbricated, glossy; feathers of the head and neck narrow and pointed; space between the bill and eye covered with small bristle-pointed feathers disposed in a radiating manner. Wings long, the fourth quill longest; the first short; the outer six abruptly cut out on the inner web. Tail rather long, ample, rounded. 12. 1. Aquila Chrysaetos, Linn. Golden Eagle. Plate CLXXXI. Female. General colour of the plumage dark brown glossed with purple; occiput, hind part and sides of the neck, light brownish-yellow; wing-coverts light brown; primary quills brownish-black, secondary with the coverts brown, those next the body more or less mottled with brownish-white, excepting at the ends; tail dark brown, lighter towards the base, with a few irregular whitish markings; feathers of the legs and tarsi, and lower tail-coverts, light yellowish-brown. Young with the basal three-fourths of the tail white. _Male_, 32, 70. _Female_, 38, 84. From Pennsylvania northward. Never seen far in the interior. Resident. Falco fulvus, Bonap. Syn. p. 25. Aquila Chrysaetos, Golden Eagle, Swains. & Rich. F. Bor. Amer. v. ii. p. 12. Ring-tailed Eagle, Falco fulvus, Wils. Amer. Ornith. v. vii. p. 13. Royal or Golden Eagle, Nutt. Man. v. i. p. 62. Golden Eagle, Falco Chrysaetos, Aud. Ornith. Biog. v. ii. p. 464. GENUS IV. HALIAETUS, Savigny. SEA-EAGLE.