This bird frequently appears in the United States, generally on the sea-coast in the autumn and winter, at which seasons, also, according to Mr. Lembeye, it visits the island of Cuba. It flies with extraordinary vigor and rapidity, and is remarkable for its bold and destructive habits.

2. Falco nigriceps. Cassin,[3] new species. The Western Peregrine Falcon.

Very similar to the preceding, but smaller, and with the bill disproportionately weaker. Very similar, also, to Falco peregrinus, but differing from both in the colors of the young bird, and in other characters. Adult. Frontal band of white, very narrow. Head and neck above, and cheeks, clear black, with a tinge of cinereous; other upper parts, bluish cinereous, every feather having transverse bands of brownish black, lighter on the rump and upper tail-coverts.

Throat and breast, pale reddish white; other under parts, lighter, with rounded spots and transverse bands of black, and with a tinge of cinereous on the flanks and abdomen. Tail above, pale bluish cinereous, with transverse bars of brownish black, and narrowly tipped with white. Patch of black on the cheek, very large, and scarcely separated from the same colors of the back of the head and neck.

Dimensions. Total length, females (of skin) about 17 inches, wing 13 to 13½, tail 6 to 6¾ inches; males, total length 14½, wing 11½ to 12, tail 5½ to 6 inches.

Younger. Entire plumage above, dark brown; many feathers, especially on the rump, tipped with rufous; tail above, brown, with a tinge of ashy, and barred with rusty on the inner webs. Under plumage pale reddish ferruginous, paler on the throat, all the feathers with broad longitudinal stripes of black, and many, also, with irregular transverse stripes of the same color, which predominates on the flanks and under wing-coverts, and which are marked with reddish white bars and circular spots. Tibia, with transverse bars of brownish black.

Dimensions. Female (of skin), total length about 17 inches, wing 12, tail 6½ inches.

Hab. Bear creek, California, (Mr. E. M. Kern.) Coast of Lower California, (Dr. Heermann.) Chili, (Lieut. Gilliss.) Spec. in Mus. Acad. Philada., and Nat. Mus. Washington.

Obs. This bird, of which we have seen numerous specimens, appears to be distinct from Falco anatum. It is uniformly smaller than either that species or F. peregrinus, but resembles Indian or other Asiatic specimens of the latter strongly. The young differ from the young of the species just mentioned, especially in the deeper and different red color of the under parts of the body. In this character they more resemble Falco peregrinator of India, Falco puniceus of Africa, Falco melanogenys of Australia. It has also generally the cheeks as strongly marked with a black patch as the latter, and can, by that character, be distinguished from either F. anatum or F. peregrinus.

This species appears to inhabit the western portion of America as far south as Chili.

3. Falco polyagrus. Cassin, new species. The American Lanier Falcon.

General form robust; bill, rather short, very strong; tooth, prominent; wing, long, second and third quills longest, and nearly equal; tail, rather long. Female nearly adult. Narrow frontal band; line over the eye, cheeks and entire under parts, white; narrow stripe from the corner of the mouth, dark brown; some feathers on the breast and abdomen, with longitudinal stripes and spots of brown, which color forms a large spot on the flank, plumage on the sides also with spots of brown. Entire plumage of the upper parts, brown, many feathers with rufous edgings; paler on the rump; tail above, grayish brown, with transverse bars of white, and narrowly tipped with the same color. Quills, dark grayish brown, with numerous bars of white on their inner webs; under wing-coverts, dark brown, edge of wing at the shoulder and below, white, spotted with brown. The brown of the back extending somewhat on to the breast at the wing-joint. Bill, bluish horn color, under mandible yellow at its base. Large space around the eye, bare, with a narrow edging of brown on the first plumage encircling it.

Younger Female. Entire plumage brownish black, throat white, and many feathers on the under parts with edgings and circular spots of white; under wing-coverts, also, with circular spots of white; under tail-coverts with wide transverse stripes of white. Young Male? Frontal band nearly obsolete; entire upper parts, uniform brown, with narrow rufous stripes on the head; under parts, white, with a tinge of reddish yellow, and nearly every feather with a narrow longitudinal stripe of blackish brown; large spaces on the flanks brown. Tarsi and feet lead colored.

Dimensions. Female (of skin), total length about 20 inches, wing 14, tail 8 inches.

Hab. Sources of the Platte river, (Dr. Townsend.) California, (Dr. Heermann.) Puget’s Sound, (U. S. Ex. Exp. Vincennes.) Spec. in Mus. Acad. Philada., and in Nat. Mus. Washington.

Obs. Very similar, in the two first stages of plumage above described, to Falco jugger of India, (Gray’s Illustrations of Indian Zoology, II. pl. 26, and Jerdon’s Illustrations of Indian Ornithology, pl. 44,) but larger. We have, however, never seen the young of F. jugger in the plumage of the young of our species as described above, from Dr. Heermann’s Californian specimens. This is the first species of this group of Falcons (the Laniers and Juggers) yet discovered in America, and is especially remarkable on account of its near affinity to the Asiatic species.

II. GENUS HIEROFALCO. Cuvier, Reg. An. I. p. 312, (1817.)

Size, large. Bill, short, thick, distinctly toothed, and with a slight festoon; wings rather shorter than in Falco; tarsi and toes shorter, the former covered with small circular scales. Color of adult usually white. Contains several species inhabiting the northern regions of both continents, nearly all of which where regarded with great favor for the purposes of Falconry.