Vol. 35, pp. 39-40 March 20, 1922 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



Xr 



DESCRIPTION OF A BRACHYSPIZA FROM THE 

 CHACO OF ARGENTINA AND PARAGUAY. 



BY ALEXANDER WETMORE. 



During a review of the more southern forms of the South 

 American song sparrow, incident to the identification of a series 

 of specimens collected by the writer during 1920 and 1921, a 

 subspecies previously undescribed has been recognized from 

 the region known as the Chaco. Its characters may be known 

 from the following diagnosis. 



Brachyspiza capensis mellea, subsp. nov. 



Character s.Simileir to Brachyspiza capensis argentina Todd but paler; 

 underparts mainly white with no distinct wash of gray on breast; sides and 

 flanks much lighter, more buffy; brown half collar on hindneck lighter; 

 dorsal surface lighter particularly on rump, with dark longitudinal streaks 

 somewhat more restricted. 



Description. — Type, U. S. National Museum, Cat. No. 284146, adult 

 male, collected 80 kilometres west of Puerto Pinasco, Paraguay, September 

 16, 1920, by Alex. Wetmore (orig. No. 5010). Median crown stripe moder- 

 ately wide, grayer than pale mouse gray; superciliary stripe white with a 

 wash of pale olive-gray, extended to base of bill where it is slightly expan- 

 ded; basal feathers dull white with an admixture of black; auricular region 

 pale mouse gray, indistinctly streaked with white; broad lateral crown 

 stripes, line behind eye, another below auricular region and a spot on either 

 side of breast black; a few hair-like black feathers above anterior canthus 

 of eye; feathers on lower eyelid white, those below eye whitish mixed with 

 black; collar on hindneck rather narrow, extended around to black spot 

 on either side of breast, in color slightly duller than tawny; back, rump, 

 upper tail-coverts and scapulars light grayish olive; back and scapulars 

 streaked with black, with a distinct space between longitudinal streaks and 

 brown collar on hindneck; external webs of scapulars bordered with avel- 

 laneous ; flight feathers blackish brown ; primaries edged narrowly with dull 

 pale olive-buff; secondaries more broadly margined with avellaneous, 

 almost white at tips; wing coverts blackish brown; lesser wing coverts 

 margined with smoke gray; median wing coverts tipped with white forming 

 7_Proc. Biol. Soc. Wash., Vol. 35, 1922. (39) 



