THE GENUS CHORDEILES SWAINSON — OBERHOLSEE. 53 



light gray and whitish with a minimum of buff. The male of this 

 subspecies is readily distinguishable from Chordeiles mrginianus vir- 

 ginianus by its much lighter upper surface, the dark ground color 

 less blackish, more grayish brown, the light mottlings much more 

 numerous, finer, paler, and less ochraceous (more whitish or grayish) ; 

 and also by its lighter lower surface, the posterior portion white 

 instead of more or less tinged with buff or cream color, and less 

 heavily barred with blackish, and the dark brown of anterior por- 

 tion more grayish. 



The female is more brownish below on the dark areas than is the 

 male, also more washed with buff on the posterior portion ; above usu- 

 ally darker and with less white mottling, the dark areas slightly 

 more brownish, the light markings duller, more brownish, or more 

 tinged with buff or ochraceous (not so whitish), and thus not so 

 sharply contrasted. She differs from the female of Chordeiles vir- 

 ginianus virginianus in much lighter, more grayish (less brown- 

 ish) upper surface, with much more numerous light markings; and 

 paler lower parts, the dark portions more grayish (less brownish), 

 the light areas more whitish (less tawny or ochraceous), and pos- 

 teriorly less heavily brown-barred. From the female of Chordeiles 

 virginia7ius hesperis she may be distinguished above by the some- 

 what lighter, more grayish shade of the dark brown ground color, 

 and more whitish (less ochraceous), and usually more numerous light 

 markings, the cervical streaks particularly paler, less buffy; and 

 below by her somewhat paler and more grayish general cast, and the 

 less deeply buff-tinged and less heavily barred posterior portion. 



The first autumn plumage is lighter above than that of any of the 

 other races, so much so that no special comparison is necessary ; the 

 upper surface being of a pale silvery gray, finely vermiculated, and 

 sometimes also spotted with black and dark brown — really a very 

 beautiful bird. As in the adult there is, however, much individual 

 variation; some specimens are much more coarsely vermiculated, 

 and even blotched and streaked with black above; some examples 

 have a pure gray cast, others have a decided tinge of buff both above 

 and below. 



The nestling is usually pure white or cream white below, and duller, 

 buffy white, with dark gray markings above; but occasionally pale 

 fawn color below, and fawn color with Prout's brown markings 

 above. 



Individual variation has about the same range in the female as in 

 the male. The latter is normally pale above, with numerous light 

 grayish or whitish mottlings, from which it varies in occasional ex- 

 amples to a bird much more extensively blackish above, with much 

 less light mottling and practically not distinguishable from typical 



