SYNOPSIS OF NORTH AMERICAN BIRDS. II. FAMILY FALCONIDÆ. THE FALCONS, HAWKS, EAGLES, KITES. Head and neck usually covered with feathers, but in a few instances partially naked; bill, usually very strong, curved and very sharp; tarsi and toes, generally strong and muscular; claws, curved, sharp; wings, various, but usually large, and adapted to swift and vigorous flight. Size, very much varied, body generally very compact, and organized for strength and activity of habits, and for the destruction of living animals. Female larger than the male. Inhabit all parts of the world, numerous in the temperate and torrid regions. I. SUB-FAMILY FALCONINÆ. THE TYPICAL FALCONS. Bill, short, hooked, upper mandible always furnished with a well defined tooth; head, rather large; feet and tarsi, very strong; toes and claws, long, the latter very sharp and strong; wings, long, pointed; tail, rather lengthened. Embracing about fifty species, inhabiting all parts of the earth, and may be regarded as presenting the highest organization of the Rapacious form of Birds. A. I. Genus Falco. Linnæus Syst. Nat., I. p. 124. (1766.) General form, robust and powerful; bill, short, with the upper mandible curved, and with a distinct tooth; nostrils, circular, with a central tubercle. Wings, long, pointed, formed for vigorous and rapid flight; tail, rather long; tarsi, short, robust, covered with rounded or hexagonal scales; middle toe long, claws large, curved, and very sharp. This genus, as restricted, contains from fifteen to twenty species, found in various parts of the world, several of which more or less intimately resemble the _Falco peregrinus_ of Europe, and the _Falco anatum_ of America. They are remarkable for exceedingly rapid flight, and great boldness in attacking animals on which they prey. 1. Falco anatum. Bonap. Comp. List p. 4. (1838.) “Falco peregrinus Gm.” Wilson, Audubon and other authors. Edwards’ Birds, I. pl. 3, 4. Wilson Am. Orn. IX. pl. 76. Aud. B. of Am. pl. 16, octavo edition, I. pl. 20. De Kay, Nat. Hist. State of New York Birds, pl. 3. fig. 8. Lembeye B. of Cuba, pl. 1. fig. 2. Bill, rather short, strong, very sharp, with a well defined tooth in the upper mandible; wings long, legs strong, middle toe long, claws curved, sharp. Adult. Frontal band white; top of the head, back, wing-coverts and rump, bluish cinereous; every feather crossed transversely with bands of brownish black; rump and lower part of the back lighter, and with the dark bands less numerous.