410 
NORTH AMERICAN BIRDS. 
length about 5.30, wing 2.55-2.95 (2.71), tail 1.95-2.30 (2.11), 
exposed culmen .48-.52 (.49), depth of bill at base .26-.29 
(.28), tarsus .80-.95 (.87). Hab. Coasts of southern California, 
Lower California, and Sonora; south, in winter, to Cape St. 
Lucas and Guaymas. 
544, A. rostratus Cass. Large-billed Sparrow. 
@. Bill from nostril only .32, depth of bill at base only .22; general 
color above dull brownish slate; length about 5.00-5.15, wing 
2.55, tail 1.95, culmen .45, tarsus .82. Hab. Vicinity of Cape 
St: Lititas. j.cccc ss. cuevteey 544a. A. rostratus guttatus (Lawe.). 
St. Lucas Sparrow. 
b. Tail deeply emarginate, the lateral pair of feathers longest, the depth of 
the emargination equal to distance from eye to nostril, the feathers all 
narrow and pointed at tip; crown buff, streaked with black laterally. 
(Subgenus Centronyx BatrD.) 
Adult: Head ochraceous or buffy, deepest on crown, nearly or quite 
white on chin and throat; top of head streaked with black, es- 
pecially laterally ; maxillary stripe bordered above and below by 
blackish rictal and submalar stripes; lower parts white, the chest, 
sides, and flanks streaked with black; upper parts light brownish, 
varied by lighter edgings and blackish spotting. Young: Similar 
to adult, but feathers of crown and back distinctly bordered with 
buffy, and streaks on chest less sharply defined. Jn winter, the 
buffy coloring much more pronounced than in summer, strongly 
tingeing chest and sides. Length 5.10-5.85, wing 2.65-3.05. Nest 
on ground, in open grassy situations, composed of dried grasses, 
ete. Eggs 3-5, .79 X .59, whitish (varying in tint), spotted with 
reddish brown and lined with black. Had. Great Plains, from 
Dakota and Montana to the Saskatchewan in summer; south, in 
winter, to Texas, New Mexico, and Arizona. 
545. A. bairdii (Aup.). Baird’s Sparrow. 
a. Outer pair of tail-feathers shorter than middle pair; difference between length 
of tail and wing not greater than length of bill from nostril, or else tail 
longer than wing and much graduated (“‘ Coturniculus” leconteiz), or depth of 
bill at base equal to its length from nostril (“ Coturniculus” savannarum). 
b'. Crown divided by a very distinct lighter median stripe, between two lateral 
blackish ones. Vest on ground, bulky, with deep cavity, often more or 
less arched over on top, composed of dried grasses. Eggs 3-5, white, 
speckled or spotted, chiefly on larger end, with reddish brown, some- 
times mixed with a few small blackish markings and touches of lilac- 
gray. (Subgenus Coturniculus Bonar.) 
c'. Tail double-rounded, the lateral feathers only a little shorter than mid- 
dle pair (difference between their tips much less than length of bill 
from nostril), the middle pair much shorter than next (longest) 
pair; bill stout, its depth at base equal to or greater than length 
