THE GENUS CHORDEILES SWAINSON OBEEHOLSER. 113 



CHORDEILES RUPESTRIS (Spix). 



Oaprimulgus rupestris Spix, Avium Spec. Nov. Bras., vol. 2, 1825, p. 2, pi. 

 2 ("insulis petrosis fl. Nlgri ").* 



Chars, sp. {adult male). — First (outermost) primary longer than 

 second ; shortest secondary usually reaching or exceeding the tips of 

 the primary coverts; distance from bend of folded wing to end of 

 shortest secondary nearly always greater than from latter point to 

 end of fourth primary (counting from the outermost) ; tips of tail- 

 feathers rounded; upper surface varied with dark brown, whitish, 

 buff, and ochraceous; tail chiefly white, the two middle rectrices, 

 most of the next pair, the outer webs of outermost pair, and broad 

 tips to all, brown ; middle portion of inner primaries and basal por- 

 tion of nearly all the secondaries pure white ; the remaining portions 

 of these quills, together with the three outer primaries and the 

 primary coverts, plain fuscous, unspotted; axillars and middle por- 

 tion of under wing-coverts pure white ; lower surface pure white ; the 

 jugulum and upper breast spotted and the former more or less clouded 

 with pale brownish gray or grayish brown. 



Adult female. — Similar to the adult male, but smaller; upper parts 

 more ochraceous or buffy, less closely vermiculated, and rather lighter ; 

 fourth primary (counting from the outermost) with usually at least 

 a small spot of white on middle part of inner web; tail with the 

 broad brown tips much mottled with lighter, instead of usually plain 

 brown or nearly so ; those rectrices that are mostly white having more 

 dark brown at base (commonly none in the male) , and the white area 

 of inner web with one or two spots or bars of dark brown ; outer web 

 of outermost rectrix all brown without a subterminal white area, and 

 this brown much, instead of little or not all, mottled with lighter. 



Remarks. — The present species seems to be a comparatively rare 

 one, and the small number of specimens now available precludes any 

 satisfactory elucidation of the various plumages, molt, variation, and 

 the many other problems connected with every species. Individual 

 variation seems to concern chiefly size ; the shade of the markings on 

 the breast ; the amount of white on the greater wing coverts ; and the 

 coarseness of the markings on the upper surface. 



Geographical distribution. — The geographical distribution of 

 Chordeiles rupestris is entirely in northern and central South Amer- 

 ica, and extends from northern Brazil to Colombia, Peru, and Bolivia. 

 To the single race previously recognized the present investigation 

 adds two, one from central Colombia, the other from eastern Peru. 

 Both of these, however, are known from only a limited area, and by 

 far the greater part of the total range of the species is occupied by 

 the typical subspecies, Chordeiles rupestris rupestris. 



1 Further synonymy under subspecies. 



