FALCONID^ — THE FALCONS. 



293 



Sp. Char. Form strong and heavy, like B. borealis, but still more robust; tibial plumes 

 unusually developed, long and loose, their ends reaching to or beyond the base of the 

 toes; lateral toes nearly equal. Four outer primaries with inner webs cut. Dimensions: 

 Wing, 14.25-15.75; tail, 8 80-10.00; culmen, 1.00; tarsus, 2.75-3.25; middle toe, 

 1.50-1.70. Colors: Nearly uniform black, varying from a sooty to a carbonaceous tint, 

 with more or less of concealed pure white. Adult. Tail confusedly mottled longitudi- 

 nally, with grayish, dusky, and white, often tinged or mixed with rufous, the different 

 shades varying in relative amount in different individuals ; a subterminal band of black. 

 Young. Tail grayish-brown, crossed by about nine very regular and sharply defined, 

 broad bands of black, about equal in width to the gray ones. 



Adult male (Lawrence, Kansas, Oct., 1871 ; in Col- 

 lection of Kansas University). General color deep, 

 almost carbonaceous, black, showing much exposed 

 white on the head, neck, and breast, all the feathers 

 of which are snowy white beneath the surface, the 

 black being merely in the form of tear-shaped spots 

 on the terminal portion of the feather ; chin, lores, 

 and front pure white ; upper parts in general, the 

 posterior lower parts and the lining of the wing, with 

 the black unbroken, but all the feathers — except the 

 under wing-coverts — more or less spotted with white 

 beneath the surface, on a grayish ground; these spots 

 being usually arranged in pairs on each side of the 

 shaft, on the flanks ; tail-coverts, above and below, 

 spotted irregularly with bright rufous, in nearly equal 

 amount with the black and white. Alulae, primary 

 coverts, and primaries, with quadrate spots of plumbe- 

 ous on their outer webs, forming transverse bands; 

 under surface of primaries plumbeous-gray except at 

 ends, but much broken by coarse marbling of white, 

 this prevailing anteriorly, where it is much confused, 

 but posteriorly about equal with the grayish, and ex- 

 hibiting a tendency to form quadrate spots. Tail, with the ground-color white, but this 

 nearly hidden on the upper surface by a longitudinal mottling of dark and light ashy, this 

 growing more uniform terminally, where it becomes slightly suffused with reddish and 

 crossed by a subterminal, broad but broken and irregular, band of black, the tip again 

 very narrowly grayish and reddish. 



Wing-formula, 4,3,5-2,6; 1 = 10. Wing, 15.00; tail, 8.80; culmen, 1.00; tarsus, 

 2.75 ; middle toe, 1.50 ; lateral toes equal. Plumage of the flanks, abdomen, tibiae, and 

 crissum remarkably lengthened and lax, the latter reaching within two inches of the tip 

 of the tail, and the tibial plumes reaching to the base of the toes. 



Adult female (6,851, Rio Grande, lat. 32° ; Dr. T. C. Henry, U. S. A.). Whole plumage 

 purplish black, or chocolate-black, with a purplish lustre ; feathers everywhere pure white 

 at bases, this exposed, however, only on the occiput, or where the feathers are disarranged. 

 Forehead, lores, and chin white. Secondaries and primaries more brown than other por- 

 tions, crossed by distinct bands of black, — about six on the secondaries. Whole lining 

 of the wing and upper tail-coverts continuous, unvariegated black. Under surface of the 

 primaries ashy-white, more slaty terminally; ends with distinct, and other portions with 

 obsolete mottled, bars of dusky. Tail ashy-brown on outer webs, white on inner ; both 

 with a confused, rather longitudinal mottling of blackish; terminally, there is a broad 

 nearly continuous subterminal band indicated by blotches, these mixed very slightly with 

 a rufous tinge. Primaries injured by shot, therefore proportions of the quills cannot be 



6851. 



Buteo harlani- 



