306 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



d. Darker and smaller; adult male averaging, wing 75.95, tail 66.29; female, 

 wing 72.64, tail 65.79. (Eastern North America.) 



Spizella monticola montioola, adults (p. 307) 

 (hi. Paler and larger; adult male averaging, wing 77.47, tail 69.60; female, wing 

 75.18, tail 67.56. (AVestern North America.) 



Spizella monticola ochracea, adults (p. 309) 

 cc. No spot on breast. 



d. A black or dusky streak through eye. 

 e. Darker; ground color of back strongly brown or rusty. 

 /. Moderatel}' dark, the pileum not darker than rufous-chestnut. 



g. Smaller, with relatively smaller bill; color of back less rusty, and 

 forehead less extensively black; male, wing averaging 69.09, tail 

 56.90; female, wing 66.55, tail 54.61. (Eastern North America.) 

 Spizella sooialis socialis, adults (p. 311) 

 gg. Larger, with relatively stouter bill; color of back more rusty, and 

 forehead more extensively black; male, wing averaging 72.39, tail 

 60.20; female, wing 66.29, tail 60.45. (Southern Mexico; north- 

 western Guatemala?.) Spizella socialis mexicana, adults (p. 313) 



ff. Very dark, the pileum deep or dark chestnut. (Eastern Guatemala 



and Honduras.) Spizella socialis pinetorum, adults (p. 314) 



ee. Paler; ground color of back pale wood brown or grayish buffy. ("West- 

 ern North America and south into Mexico. ) 



Spizella socialis arizonae, adults (p. 315) 

 dd. No black or dusky streak through eye. 



e. A rusty postocnlar streak, or else pileum mostly gray; no white orbital 

 ring; under tail-coverts wholly white. 

 /. Smaller and more rusty; male, wing averaging 60.96, tail 58.93; female, 

 wing 60.96, tail 58.93. (Eastern United States.) 



Spizella pusilla pusilla, adults (p. 318) 

 ff. Larger and grayer (pileum sometimes almost wholly gray); male, wing 

 averaging 69.60, tail 68.83; female, wing 61.98, tail 62.74. (Great 

 Plains, North Dakota to Texas. ) 



Spizella pusilla arenacea, adults (p. 320) 

 ee. No rusty postocnlar streak; a more or less distinct white or whitish 

 orbital ring; under tail-coverts pale brownish gray centrally. (East- 

 ern part of Mexican plateau north to southern New Mexico.) 



Spizella wortheni, adults (p. 321) 

 bb. Pileum not rufous or rusty. 



c. Pileum wholly gray Spizella atrogularis, adults and young (p. 322) 



cc. Pileum light brownish, streaked Avith black. 

 d. Pileum with traces of rufous (at least concealed). 



e. Darker and smaller Spizella socialis socialis, immature 



ee. Paler, more buffy, and larger Spizella socialis arizonae, immature 



dd. Pileum without trace of rufous. 



e. Pileum with a median stripe (more or less distinct) of pale grayish or 

 buffy, the lateral stripes more heavily streaked with black; sides of 

 head with markings strongly contrasted. (Great Plains, from British 

 America to Mexico, and in winter to Arizona and Lower California. ) 



Spizella pallida, adults (p. 324) 



ee. Pileum uniformly streaked, without median lighter stripe; sides of head 



with markings less strongly contrasted. (United States west of Rocky 



Mountains and south into Mexico.) . . .Spizella breweri, adulta (p. 327) 



