THE GENUS CHOBDEItES SWAlNSON — OBEftHOLSEE. 41 



Remarks. — ^The female of this race differs ia color from the male 

 in her usually more buffy posterior lower parts ; rather lighter, more 

 brownish (less blackish) ground color of the upper surface, with 

 light markings there averaging darker, duller, less sharply contrasted 

 with the dark areas, and usually somewhat more ochraceous or 

 brownish (less whitish) . She is, in fact, more like Chordeiles virgini- 

 anus howelli^ than is the male. She is even more different from 

 the female of Chordeiles virgvrdwrms mrgivdanus than is the male 

 from that form, being rather readily separable by her lighter, more 

 brownish (less blackish), more heavily light-mottled upper parts, 

 these light markings paler tawny or ochraceous; paler under sur- 

 face, the dark brown areas less blackish, the tawny and ochraceous 

 parts, including the throat, paler, the posterior portion more nar- 

 rowly barred and less strongly tinged with buff or tawny. 



The Juvenal and first autumn plumages are distinguishable from 

 the same stages of Chordeiles virgmicmus virginianus and Chordeiles 

 virginianus chapTncmi by their lighter upper surface, the ground 

 color of which is more brownish, the light markings usually some- 

 what more buffy and more numerous. Most specimens are, on the 

 upper surface, very much like adult male Chordeiles virginianus 

 sermetfi, occasional birds almost indistinguishable, but are rather 

 more brownish and buffy. 



Individual variation in color is very marked, more so in the female 

 than in the male. In the male the ground color of the lower parts 

 is normally creamy white, varying to pure white and to cream buff ; 

 in the female normally cream buff, varying to cream white and to 

 ochraceous buff, the light throat-patch ranging from ochraceous 

 buff to buffy white. The upper surface of the male is normally 

 blackish brown, with considerable light mottling, mostly of white 

 and grayish white, with some buff. The general impression is lighter 

 than in Chordeiles virginianus virginianics, darker than in Chor- 

 deiles virginianus sermetti. Sometimes it is more blackish, some- 

 times more brownish, and the mottlings are occasionally, at least in 

 part, ochraceous buff. The upper surface of the female is normally 

 as described above, but varies occasionally (No. 161983, U.S.N.M., 

 Quincy, California, June 21, 1889) to dark grayish brown with ex- 

 tensive white, scarcely any buff, markings, practically as in typical 

 male Chordeiles virginiamMs sennetti; to a more extensively blackish 

 general color (No. 94978, U.S.N.M., Fort Klamath, Oregon, July 25, 

 1883), with few light markings, very much like the adult male Chor- 

 deiles virginianus virginianus/ to a more rufescent brownish, though 

 dark color (No. 19839, Carnegie Mus., Beaverton, Oregon, June 28, 

 1884) , with nearly all the light markings buff, ochraceous, or tawny, 



1 See p. 57. 



