BIRDS OF NORTH AND MIDDLE AMERICA. 268 



bb. Larger (averaging wing 65.53 or more, tail 62.23 or more), with smaller white 



spot at tip of inner AA^eb of outer tail-feather (averaging only 7.62 in length). 



c. Smaller, lighter colored, and browner; averaging wing 65.53, tail 62.23; dorsal 



region distinctly brownish. (Western Texas to Utah, Xevada, southern 



California, Lower California, and northwestern ^Mexico.) 



Amphispiza bilineata deserticola Q). 265) 



cc. Larger, darker colored, and more slaty; averaging wing 67.31, tail 64.77; 



dor.sal region not distinctly brownish. (States of Hidalgo to Durango, 



central ^lexico. ) Amphispiza bilineata grisea (p. 266) 



aa. Xo white superciliary stripe; sides and flanks streaked; adults with chin, throat, 

 and chest mostly white. [Amphhpiza belli ) 

 b. Smaller (averaging Aving not more than 66.55, tail 65.02); back usually obso- 

 letely streaked or without obvious streaks. 

 c. Darker; head and neck above dull slate-gray or deep mouse gray; a broad 

 stripe on each side of throat and spot on center of chest, black. (Cali- 

 fornia, including Santa Barbara Islands, and northern Lower California.) 



Amphispiza belli belli (p. 267) 



cc. Paler; head and neck above pale smoke gray; a narrow and interrupted stripe 



on each side of throat and small spot on center of chest dull dusky grayish. 



(Ballaenas Bay, Lower California.) Amphispiza belli cinerea (p. 269) 



bb. Larger (averaging wing 77.47, tail 72.90) ; back usually distinctly streaked with 

 dusky. (Southeastern California, western Xevada, and southeastern Oregon 

 to southern Wyoming, Colorado, and western Texas.) 



Amphispiza belli nevadensis (p. 270) 



AMPHISPIZA BILINEATA BILINEATA (Cassin). 

 BLACK-THROATED SPARROW. 



A contimtous white superciliary .-^tripe; above plain gra^'ish (more 

 brownish on back), the tail blackish with more or less of white on 

 edge and tip of outermost rectrix. 



Afbilfi<{s<:,i:;:'S(iJ!h). — Con.spiciious superciliary and malar stripes pure 

 white, the former margined above l)y a narrow Ijlack line, the latter 

 not reaching to the base of the mandible: anterior portion of the malar 

 region, together with the lores, chin, throat, and median portion of 

 chest uniform black, the last with a convex (sometimes angular) poste- 

 rior outline; rest of under parts white, shading into grayish on sides 

 and tianks, the latter, together with anal region and under tail-coverts 

 tinged more or less with Ijufly in winter plumage; upper parts deep, 

 slightly brownish, gray, becoming more brownish (nearh" hair brown) 

 on dorsal region and wings; sides of head (between the two white 

 stripes) plain gray, like pileum; lateral tail-feather with outer web 

 chietiy or wholly white, the inner w^eb with a large terminal white spot, 

 averaging 1-1. To ^ mm, in length; second (sometimes third, rarely also 

 fourth) tail-feather with a smaller white terminal spot; maxilla, black- 

 ish; mandible, pale gravish blue with dusky tip: iris deep brown; legs 

 and feet l)rownish black. 



Young. — Similar to adults but without any distinct black markings 

 on head, etc., the chin and throat white, sometimes flecked with graj- 



^Sometimes as much as 17.78 mm. loiiii. 



