Large, general form, rather slender; wings, short. Adult. Head above, neck behind and stripe from behind the eye, black, generally more or less mixed with ashy; other upper parts bluish cinereous, with the shafts of the feathers black; a conspicuous stripe over the eye, and an obscure collar on the back of the neck white. Entire under parts white, every feather with a longitudinal line of brownish black, and several transverse narrow and usually irregular bands of ashy brown. Quills, brown, with bands of a deeper shade of the same color, and with mottled white bands on their inner webs. Tail, dark brownish cinereous, with irregular bands of brownish black, and narrowly tipped with white; under surface very pale, nearly white; under tail-coverts pure white. Young. Head above and other upper parts, dark brown mixed with rufous, especially on the head and neck. Under parts, white, tinged with fulvous, with large oblong and circular spots of deep brown. Dimensions. Total length, female, 22 to 24 inches, wing about 14, tail 10½ to 11 inches; male, 19 to 20 inches, wing 13, tail 9½ to 10 inches. Hab. Northern and eastern North America. Spec. Mus. Acad. Philada. Obs. Resembles to some extent the Goshawk of Europe, (_Astur palumbarius_,) with which it has been confounded by some American authors. It is about the same size, but may easily be distinguished by its lighter color, and by its much narrower and more numerous bands on the inferior parts of the body. It is in all respects a distinct species, as described by Wilson and by Temminck. The young male of this bird may readily be mistaken for the young female of the succeeding species, (_Accipiter Cooperi_,) but can be distinguished by the different color and markings of the under parts of the body. In some specimens of this species, the transverse bands on the under parts are so irregular or broken, as to present a nearly uniformly mottled aspect. This stage of plumage is represented in Audubon’s plate, but is not the most common. II. GENUS ACCIPITER. Brisson, Orn. I. 310. (1760.) NISUS. Cuvier, Regne An. I. p. 321, (1817.) hieraspiza. Kaup Class. p. 116, (1844.) General characters very similar to those of _Astur_, but the species are generally more slender and much smaller. Wings short, with the fourth quill usually slightly longest, shorter than in _Astur_; tail long; tarsi rather long and slender, and frequently with the scales of the tarsi nearly obsolete. Contains about twenty species of all countries, many of which bear more or less resemblance to the _Accipiter nisus_ of Europe.