BIRDS OF NORTH AND MIDDLE AMERICA. 307 



aa. Chest streaked with dusky. {Young. )^ 



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



etc., yellowish white or pale yellowish buffy...Spizeila pusilla pusilla, young 



hb. Pileum pale brown or grayish brown (rarely rusty l^rown), always distinctly 



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



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



tertials bright rusty or cinnamon-rufous. 



d. Darker Spizella monticola monticola, young 



del. Paler Spizella monticola ochracea, young 



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

 of tertials. 

 d. Auricular region lirownish 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- 

 buff y grayish or brownish, with narrower black streaks. 

 ('. 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 socialis, young 

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



Spizella socialis mexicana, young 

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



Spizella socialis arizonae, young 



SPIZELLA MONTICOLA MONTICOLA (Gmelin). 

 TREE SPARROW. 



Wing with two conspicuous white bands; adult with mandible ^^ellow, 

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

 with a dusky spot. 



Adult {sexes ah'ke). — Pileum, postocular streak (sometimes also a 

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

 chestnut; hindneck, broad superciliar}' stripe, and sides of head and 

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

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

 paler; ])reast, abdomen, and under tail-coverts dull white, the tirst 

 with a dusk}' median spot or blotch at upper edge, next to the pale 

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

 bufl'y; back and scapulars pale grayish buffy, Ijroadh^ streaked with 

 black and, more narrowly, Avith 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 indistincth^ streaked with darker; tail grayish 



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

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



