Dimensions. “Length, 3 feet 7 inches; extent of wings, 10 feet 2 inches; bill, 3¼ inches along the back; along the gap which commences directly under the eye to the tip of the lower mandible, 3¼ and 1¾ deep; length of wing when folded, 32 inches; length of tail, 15 inches; tarsus, 4½; middle toe, 4¾; hind claw, 2½ inches.” Audubon as above. Hab. Kentucky (Audubon); Western and Eastern? Spec. in Mus. Acad., Philada.? Obs. The above description we regard as that of the young bird, and consider the adult as yet unknown. No specimen precisely corresponding to Mr. Audubon’s bird, has been obtained since its discovery, and it has latterly been looked upon by Naturalists, especially in Europe, as an unusually large specimen of the young white-headed Eagle. It is probably a western species, and would be readily recognized by the transverse scutellæ of the tarsi which are continued to the base of the toes. 3. Haliaetus albicilla. (Linn.) The Gray Sea Eagle. The European Sea Eagle. Vultur albicilla. Linn., Syst. Nat., I. p. 123. (1766.) Falco ossifraga et melanaetos. Linn., Syst. Nat., I. p. 124. (1766.) Haliaetus grœnlandicus. Brehm, Vog. Deuts., I. p. 16. (1831.) Buff., Pl. Enl., 112, 415; Selby, Ill. Brit. Orn., pl. 3; Gould, B. of Eur., I. pl. 10. Large, bill large, much hooked; wings long; tail moderate. Adult. Tail white; head and neck pale yellowish-brown, in some specimens very light; all other parts of the plumage dark umber-brown; quills nearly black; bill, feet and irides yellow. Younger. Bill brownish-black; irides brown; entire plumage dark-brown, with the tail mottled with white, much varying in extent; throat paler, and in some specimens nearly white. Dimensions. _Female_—total length, about 3 feet to 40 inches; wing, 2 feet 3 inches; tail, 1 foot. _Male_—smaller. Hab. Greenland (Fabricius, Holboll). Spec. in Mus. Acad., Philada. Obs. This Eagle, which is common in Europe, and breeds in cliffs on the sea-shore, we give as an inhabitant of Greenland. We have to say, however, that the only specimen from that country which we have ever seen, and which is a young bird, presents considerable variations from European specimens, and we consider it quite possible that Dr. Brehm is right in giving it specific distinction. The young of this bird resembles that of the succeeding species (_H. leucocephalus_), and the most readily-detected difference is its larger size and longer tarsi. The adults are, however, entirely dissimilar. 4. Haliaetus leucocephalus. (Linn.) The Bald Eagle. The White-headed Eagle. Falco leucocephalus. Linn., Syst. Nat., I. p. 124. (1766.) Falco pygargus. Daud., Traité, II. p. 62. (1800.) Falco ossifragus. Wilson, Am. Orn., VII. p. 16. (1813.)