FALCONID.f; — THE FALCONS. |99 



S]iociiii(Mis are from Santa Clara, California, Fort Arlnicklo, Miradur find 

 Orizaba, iloxico, Cliilo, and liiienos Ayres ; from all jxiints the same liird. 



Tiii.s species presents a very close resemblance to the E. mclanoptcrua of 

 Europe, ..nd the mo.''^ evident s])ecitic difl'erence can only lie detected by 

 raising the wing, the under side of which is (luite different in the two, there 

 being in the European bird no trace whatever of the Ijlack jiatcli so con- 

 spicuous in the American species. The ]irimaries, also, on both webs are 

 lighter ash, while the ash of the ujiptu' parts in general is darker than in 

 Icuciiriin and invades more the head aliove, the forehead merely approacliing 

 white. The tail is more deeply emarginated, and the proportions of the jii'i- 

 maries are (piite dilferent, the second being much longer than the third, and 

 the first nearly as long as the second, far exceeding the third, instead of 

 being about equal to the fourth. In the iitchoiop/crnx, too, the black borders 

 the eye all round, extending back in a short streak from the posterior angle, 

 instead of being restricted to the anterior region and upper eyelid, as in 

 leuciiriis. 



A specimen of " E. axillaris " from Australia (13,844, T. li. Peale) appears, 

 except upon close examination, to be ab.solutely identical in all the minutiii) 

 of coloration, and in the wing-f(jrmula, with E. Icueurus ; and differs only very 

 slightly in the measurements of bill and feet, having these proportionally 

 larger, as will be seen from the table. Another {^^'1,'ul, H. Mactier War- 

 field) has the upper parts so pale as to be nearly white. 



A young specimen of E. axillaris differs from that of E. Icueurus as 

 follows : the occiput, nape, and dorsal region are stained or overlaid by 

 dull ashy-rufous, instead of dark brown i.sli-ashy ; more blackish on the head. 

 No other differences are appreciable. 



A very characteristic distinction between Icueurus and axillaris is seen in 

 the coloration of the inner webs of the secondaries: in the former, they are 

 abrujitly lighter than the outer M'ebs, often pure white, in very striking 

 contrast to the deep ash of the outer surface ; in the latter, both webs are 

 of about the same shade of ash, which is much paler than in the other race. 

 Occasional specimens of Icueurus occur, however, in which there is little 

 difference in tint between the two webs. 



LIST OF SPECIMENS EXAMINED. 



National Museum, 10 ; Philadelpliia Academy, i ; New York Museum, 2 ; Boston 

 Society, 4; Cambridge Museum, 2; Cab. G. N. Lawrence, 2; Coll. K. Kidgway, 2. 

 Total, 24. 



Measurements. 



