The _Guaviao_, as the Double-toothed Hawk is called by the Brazilians, is thirteen and a half inches long and twenty-six inches broad; the wing measures eight inches, and the tail six inches. The plumage upon the upper part of the body is blackish grey, embellished with a metallic lustre; the under portions are reddish brown, with narrow white stripes upon the throat; the rump is also white, the quills of the wings are brown, ornamented with an irregular border, which is pure white upon the inner web; the tail is black above, brown beneath, and marked with three broad and crooked lines; the eye is light carmine, the cere greenish yellow, the beak blackish grey, and the feet of a beautiful reddish yellow. The plumage of the young is brown above and white beneath, delicately marked with undulating brown lines of various shades. THE SPARROW HAWK. The SPARROW HAWK (_Nisus communis_) is the European representative of a very numerous group distributed throughout the world. These birds (see Coloured Plate IX.) are distinguished by their elongated body, small head, and delicate beak, furnished with a very sharp hook at the extremity of the upper mandible; the wings are short, tail long, and short at its tip; the tarsi are high and weak, the toes long and slender, and armed with extremely sharp claws. The plumage varies but little in its colour. This species is about one foot long, and two broad; the wing measures seven inches and two-thirds, and the tail six inches; the female is about three inches longer and five inches broader than her mate. In the full-grown bird the entire upper portion of the body is blackish grey, the under parts are white, marked with undulating reddish brown lines; the shafts of the feathers are also of the latter hue, and brighter in colour in the male than in the female; the tail is tipped with white, and has five or six black stripes. In the young birds the upper portion of the body is a greyish brown, beneath the throat white, striped with brown; the belly and legs are ornamented with irregular spots, the beak is blue, the cere yellow, the iris golden yellow, and the feet pale yellow.