FALCONID.E — THE FALCONS. 



125 



more distinct in the American bird, while in the European the bands on the 

 tail are much more distinct, and the spots forming them are on the outer webs, 

 as well as on the inner, instead of on the latter alone ; the dark bars between 

 the light spots are in the American bird much narrower and more numerous, 

 and in the young tlie light ones come to the edge of the web, instead of 

 being enclosed within the dark color. Two very young birds (i. e. in first 

 perfect plumage) appear almost identical until closely examined, the chief 

 differences being a lighter tint to the crown in the European, and heavier 

 dark stripes on the breast, besides the peculiar character of the tail-spots, 

 which are always distinctive. In shades of color, there is not the slightest 

 difference. 



I have seen no specimen of any of the Old World forms in the plumage 

 corresponding to that transversely barred above, described here as the adult, 

 though figures of the adult lanarius indicate a very similar plumage. The 

 series of the latter race at my command is unfortunately limited to a very few 

 immature specimens. One marked " ad." (56,051, Hungary ; Schliiter 

 Coll.) measures as follows : Wing, 14.50 ; tail, 8.00 ; culmen, .83 ; tarsus, 

 1.90 ; middle toe, 1.80. Its colors are as described in the synopsis (p. 1429) 

 for the young bird. 



The var. viexicanus and var. jugger, wliich are both much darker, and more 

 uniform in the coloring of the upper parts, than var. polyagrus, are more 

 nearly alike ; in fact, tlie only tangible difference that I can find between a 

 specimen of the former in the Museum of the Boston Society of Natural 

 History (No. 1,438, $ , Juv. Lafr. Collection ; " Mexico ") and two exam- 

 ples of the latter in the New York Museum, consist in the larger size of the 

 var. jugger (see synopsis), besides its whiter cheeks and more isolated and 

 distinct " mustache." A direct comparison of these two races may show 

 other tangible points of distinction, or, on the contrary, may show even 

 these slight distinguishing features to be inconstant. The former result is, 

 however, most reasonably to be expected. 



LIST OF SPECIMENS EXAMINED. 



National Museum, 9 ; Boston Society, 2 ; Philadelphia Academy, 4 ; Museum Comp. 

 Zool. 1 ; G. N. Lawrence, 2 ; R. Ridgway, 5. Total, 23. 



Habits. This is an exclusively western species, occurring from the valley 

 of the Mississippi to the Pacific coast. Specimens have been obtained as 

 far east as Illinois. Several others have been taken on the Upper Missouri 

 and the Yellowstone Eivers, in Nebraska, at Fort Thorne, New Mexico, 

 and on the Little Colorado River. A specimen was shot by Dr. Heer- 



