BIRDS OF NORTH AND MIDDLE AMERICA. 307 



aa. Chest streaked with dusky. {Young.y 



b. Pileum rusty brownish, usually without distinct, if any, dusky streaks; throat, 



etc., yellowish white or pale yellowish bufiy...Spizella pusilla pusilla, young 



bb. Pileum pale brown or grayish brown (rarely rusty brown), always distinctly 



streaked with dusky; throat, etc., white or grayish white. 



c. Larger; spot on sides of chest, outer webs of scapulars and broad edgings to 



tertials bright rusty or cinnamon-rufous. 



d. Darker Spizella montioola monticola, young 



da. Paler Spizella monticola ochracea, young 



cc. Smaller; no bright rusty on sides of chest, outer webs of scapulars, nor on edges 

 of tertials. 

 d. Auricular region brownish buffy, conspicuously different in color from 

 adjacent parts; ground color of back and scapulars clear buff, with very 



broad black streaks Spizella pallida, young 



dd. Auricular region more or less light grayish, not conspicuously different in 

 color from adjacent parts; ground color of back and scapulars light- 

 buffy grayish or brownish, with narrower black streaks, 

 c. Smaller; primaries and rectrices dark brownish gray or hair brown, edged 



with pale grayish buffy , . Spizella breweri, young 



ee. Larger; primaries and rectrices dusky, edged with grayish or buffy 

 grayish. 

 /. Darker, with ground color of back, etc., not grayish buffy. 



g. Lighter buffy brown above, with narrower black streaks; bill smaller. 



Spizella socialis Booialis, young 

 gg. Darker buffy brown above, with broader black streaks; bill stouter. 



Spizella socialis mexicaua, young 

 ff. Paler, with ground color of back, etc. , grayish buffy. 



Spizella socialis arizonse, young 



SPIZELLA MONTICOLA MONTICOLA (Gmelin). 

 TREE SPARROW. 



Wing with two conspicuous white bands; adult with mandible yellow, 

 pileum and patch on sides of chest chestnut-rufous and middle of chest 

 with a dusky spot. 



Adult {sexes alike). — Pileum, postocular streak (sometimes also a 

 rictal streak) and patch on sides of chest chestnut-rufous or rufous- 

 chestnut; hindneck, broad superciliary stripe, and sides of head and 

 neck (except as described) light gray (smoke gray or olive-graj^), the 

 first more or less tinged with rusty; chin and throat similar but 

 paler; breast, abdomen, and under tail-coverts dull white, the first 

 with a dusky median spot or blotch at upper edge, next to the pale 

 grayish of the chest; sides and flanks pale wood brownish or brownish 

 buffy; back and scapulars pale grayish buffy, broadly streaked with 

 black and, more narrowlj^, with rusty, the latter chiefly on outer 

 webs, those of the scapulars almost wholly rusty; rump and upper 

 tail-coverts plain hair brown or light broccoli brown, the former 

 sometimes narrowly and indistinctly streaked with darker; tail grayish 



' The young of S. atrogularis, only, is without distinct streaks below. Those of S. 

 wortheni and S. vusilla arenacea have not, however, yet been seen by me. 



