190 NORTH AMERICAN BIRDS. 



occiput, another from beneath eye across ear-coverts, and gi'ound-color 

 of chest, dull white ; middle of crown and occiput rusty brownish, mixed 

 with dusky; feathers of hind-neck and upper back rufous, each marked 

 with, a central oval spot of rusty white ; feathers of breast and belly 

 white centrally, broadly bordered with black. Adult female : Yery simi- 

 lar to same sex of C. virginianus cubanensis, but smaller, the sides and 

 flanks less barred with black, more white on breast, and ground-color of 

 upper parts clearer grayish. Wing 4.00-4.20, tail 2.25-2.60, culmen .60, 

 tarsus 1.12-1.20, middle toe 1.05-1.10. Hab. Yucatan. 



C. nigrogularis (Gould). Yucatan Bob White.^ 



Genus OREORTYX Baird. (Page 185, pi. LYI., fig. 3.) 



Species. 



Adult male : Upper parts plain brown or olive, the inner webs of the tertiala 

 broadly edged with buff}^ or ochraceous, producing, when wings are closed, a dis- 

 tinct stripe on each side of rump ; breast and part of head plumbeous ; crest black ; 

 entire throat uniform rich chestnut, growing blackish along upper posterior border, 

 and sending a blackish branch up to the eye ; chin, anterior portion of malar region, 

 lower portion of lores, and distinct line bordering the throat-patch from the pos- 

 terior angle of the eye downward, white ; flanks rich chestnut, broadly barred with 

 black and white; thighs rufous, and under tail-coverts black. Adult female : Hardly 

 distinguishable in color from the male, but crest usually smaller. Young : Head, 

 neck, and back grayish brown, speckled with white ; breast more decidedly gray, 

 with larger, more triangular, white spots ; throat and cheeks mixed whitish and 

 dusky ; crest-feathers blackish, their tips speckled or zigzagged with pale fulvous ; 

 scapulars, wing-coverts, tertials, and tail-feathers pale brownish, finely vermiculated 

 with dusky, the first more or less blotched with black, and the tertials edged with 

 the same, with a subedging of pale fulvous ; belly whitish ; flanks washed with 

 chestnut ; a dusky patch on ear-coverts, with a whitish line just above. Downy 

 young : Head and neck light brownish buff", deeper on lores, forehead, and a very 

 broad superciliary stripe, the space enclosed between the two latter, of opposite 

 sides, and also a broad stripe down middle of back and rump, dark chestnut, bor- 

 dered along each side by blackish ; a broad pale buffy or dull whitish stripe along 

 each side of rump, throwing off", at about midway of its length, a lateral branch 

 obliquely across the flanks, this last also bifurcating at about the middle and throw- 

 ing off posteriorly a broad stripe parallel with that of the rump, the space between 

 the two, and also that bordering the outer side of anterior half of rump-stripe and 

 anterior edge of main flank-stripe, brownish black, or dark seal-brown ; on side of 

 head, behind eye, a broad Y-shaped mark of brownish black, having its apex at the 

 posterior corner of the eye ; breast and belly dull grayish white. Length about 

 10.50-11.50, wing 5.25-5.40, tarsus 1.18-1.40. Eggs 1.36 X 1-02, cream-color, or 

 creamy buff, varying as to depth of color. 



1 Onyx nigrogularis Gould, P. Z. S. 1842, 181 ; Mon. Odont. 1850, pi. 4. 



