458 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



Range. — Highlands Costa Rica to western Ecuador. (Two species.) 

 The species which I have felt compelled to make the type of a new 

 genus has always been placed in Buai'veinon, but evidently has nothing 

 to do with the birds which properly constitute that genus. In style 

 of coloration it somewhat resembles some of the species of Atlapetea^ 

 especially those with chestnut pileum and yellow belly, which, also, 

 were formerly placed in Bnarrtiiion; but in structural characters it 

 comes far nearer to Arremon, from which its very different style of 

 coloration, more rounded wing, relatively longer middle toe, and dif- 

 ferently shaped and partially decomposed rectrices serve to readily 

 distinguish it. 



Lyswnis cctstaneiceps (Sclater) resembles Z. crassirostris in coloration, 

 except that the under parts, posterior to the throat, are wholly olive- 

 green and there are no white markings on the head. It is quite 

 identical structurallj' also, and there can be no question that the two 

 species are strictly congeneric. It belongs to eastern Ecuador and 

 Colombia (province of Antioquia). 



KEY TO THE SPECIES OP LYSURUS. 



a. Abdomen yellow; a white malar stripe, flecked with dusky. (Costa Eica and 



Veragua. ) Lysurus crassirostris (p. 458) 



aa. Abdomen olive-green like rest of under parts; no white malar stripe. (Colombia 

 and eastern Ecuador.) Lysurus castaneioeps (extralimital).' 



LYSURUS CRASSIROSTRIS (Cassin). 

 BARRANCA SPARROW. 



Adults {sexes alike). — General color deep olive-green; pileum and 

 hindneck chestnut; lower breast and abdomen lemon yellow; sides of 

 head, chin, and throat grayish dusky or blackish, relieved by a malar 

 stripe of white, flecked with dusky, the chin (sometimes upper throat 

 also) with some admixture of white; maxilla blackish, paler along 

 tomium; mandible pale brownish (in dried skins); legs and feet dark 

 brownish. 



Adult male.— Length, (skins), 142.24-161.29 (151.64); wing, 71.12- 

 80.01 (75.44); tail, 59.69-68.58 (64.01); exposed culmen, 13.21-14.73 

 (13.97); depth of bill at base, 8.38-9.65 (8.89); tarsus, 27.94-29.21 

 (28.45); middle toe, 18.54-20.32 (19.30).' 



Highlands of Costa Rica (Barranca, Buena Vista, Rio Sucio, etc.) 

 and Veragua (Cordillera de Tol6, Cordillera del Chucu, Santiago, 

 Cascajal-Cocle^ etc.). 



jSwari-emon cTOssirosin's Cassin, Proc. Ac. Nat. Sci. Phila., Aug., 1865, 170 (Barranca, 

 Costa Rica; U.S. Nat. Mus.).— Salvix, Proc. Zool. Soc. Lond., 1867, 140, pi. 

 14 (Cordillera de Tol^, Santiago, and Cordillera del Chucu, Veragua); 1870, 



^ Biinrremon ccmlaneiceps Sclater, Proc. Zool. Soc. Lond., 1859, 441 (Rio Napo, 

 e. Ecuador; coll. P. L. Sclater). 

 ^ Two specimens. 



