FALCONIDiE — THE FALCONS. 
139 
fectly melanistic condition, in which the bird is almost uni- 
formly black, and the tail with continuous, regular bars of 
black to the base. Hab. Western Province of North America, 
from the Rocky Mountains to the Pacific. ( Black Red-tail.') 
var. calurus . 
6. B. harlani. Wing, 15.00-16.20; tail, 8.80-10.50; culmen, 1.00; 
tarsus,. 2.75-2.90 ; middle toe, 1.50-1.70. Lateral toes nearly equal; 
tibial plumes much developed, reaching below the bases of the toes. 
Entirely brownish-black (except the tail), the concealed bases of the 
feathers- snowy-white. Adult. Tail confusedly mottled with dusky 
and white, upon a grayish ground ; sometimes more or less tinged 
with rufous. Young. Tail grayish-brown, with nine very regular, 
sharply defined bands of brownish-black, about equal in width to the 
gray ones. Lower parts wholly dusky. Hab. Southwestern United 
States, east of the Rocky Mountains, from Kansas to Texas. {Harlan's 
Buzzard.) 
7. B. cooperi. Wing, 15.75; tail, 9.10; culmen, 1.10; tarsus, 3.25; 
middle toe, 1.70. Adult . Head, neck, and beneath, pure white, the 
head above and nape streaked with dusky ; lining of the wing white, 
with a large black patch. Above nearly uniform dusky, the primaries 
plumbeous. Tail longitudinally mottled with light rufous, cinereous, 
and dusky ; the former prevailing. Hab. Santa Clara County, Cali- 
fornia. {Cooper's Buzzard.) ■ 
Gen“us ARCHIBTJTEO, Brehm. (Page 125.) 
^ -Common Characters. Tail more or less white basally ; inner webs of the pri- 
maries white, without bars, anterior to their emargination. Head and neck 
with longitudinal streaks of whitish and dusky (except in melanistic individuals 
of lagopus var. sancti-johannis). 
1. A. ferrugineus. Wing, 15.90-19.60; tail, 9.50 - 11.00; culmen, 1.00- 
1.20; tarsus, 3.10-3.45; middle toe, 1.40-1.65. Bill wide, the base very 
broad and depressed. Beneath, continuous pure white, without conspicuous 
spots, except sometimes a few scattered ones along the sides, and across the 
abdomen; breast immaculate, or with only narrow shaft-streaks. Upper 
parts always with more or less rufous. Adult. Upper parts and tibiae 
fine rufous, the former with longitudinal spots, the latter with transverse 
bars, of blackish. Secondaries and primaries plumbeous, the latter with 
a hoary cast. Tail white, washed with pale ash, and more or less stained 
along the edges of the feathers (longitudinally) with light rufous ; some- 
times with a badly defined indication of a dusky subterminal bar. Young. 
Above dark grayish-brown, with' only the borders of the feathers rufous 
or ochraceous ; tibiae white, with sparse transverse spots of dark brown. 
Tail white only on basal third, and on inner webs, the remaining por- 
tion brownish-ashy, with several more or less distinct darker bands. Hab. 
Western North America, from Arizona, California, and Oregon, east to the 
Great Plains. ( California Sguirrel-IIawk.) 
2. A. lagopus. Wing, 15.75-18.20; tail, 8.70-10.50; culmen, .80-1.00; 
tarsus, 2.30-2.80; middle toe, 1.30-1.50. Bill narrow, compressed; be- 
neath more or less spotted with dusky, which usually predominates ; breast 
with large spots of dusky ; no rufous on upper parts, nor on tibiae. Adult. 
