272 BISTORT OF THE 



Iris light yellowish brown; bill dark horn blue, with sides at 

 base, also cere, greenish yellow; feet bright yellow; claws black. 



This large species inhabits the prairies and plains. In other 

 respects, its habits are not noticeably different from the Ameri- 

 can Rough-legged Hawk. 



Their nests are usually placed in trees, occasionally upon high, 

 rocky cliffs. May 27th, 1883, I found a nest in a Cottonwood 

 tree, on the Smoky Hill Eiver, near Wallace, Kansas, contain- 

 ing four young birds, not over two weeks old (downy whitish 

 little fellows, with bluish black skins). The nest, a bulky one, 

 at least three feet in diameter at the base, was composed of 

 sticks and dead twigs from the tree, and sparingly lined with 

 weeds and grasses. And May 4th, 1884, my brother found a 

 nest, containing four eggs, in northern Dakota, upon the ground, 

 upon a precipitous hillside. It was made of sticks, interwoven 

 with buffalo ribs, stems of weeds and bits of turf, and lined with 

 grass. Eggs usually three or four; average measurement of 

 eight, 2.49x1.96; ground color dull cream white; irregularly 

 spotted and splashed with varying shades of brown (upon some 

 the markings are very faint); in form, rather rounded oval. 



Genus AQUILA Bkissox. 

 "Form robust and structure powerful; the bearing and general aspect that 

 of Buteo and Archihuteo. Wing long, the primaries long and strong, with their 

 emargluations very deep. Tail rather short, slightly rounded or wedge shaped. 

 Bill stronger than in the preceding genera, its outlines nearly parallel, and the 

 tip somewhat inclined backward at the point; commissure with a more or less 

 prominent festoon; nostril narrow, oval, vertical; skin of the cei'e very hard and 

 firm; superciliary shield very prominent. Feet very strong, the membrane be- 

 tween the outer and middle toes very well developed; tarsus less than twice as 

 long as the middle toe; outer toe equal to, or longer than, the inner; claws very 

 long and strong, very much graduated in size; scutelhe of the toes small, except 

 on the terminal joint, where they form broad, transverse plates; tarsi densely 

 feathered all round down to the base of the toes; tibial plumes well developed, 

 loose webbed, tlieir ends reaching down to or beyond the base of the toes. 

 Feathers of the nape and occiput lanceolate, acute and distinct, forming a nuchal 

 "cape" of differently-formed feathers. Third to fifth quill longest; first shorter 

 than seventh; outer five or six with their inner webs deeply emargiuated." 



