BIRDS OP NORTH AND MIDDLE AMERICA 265 



middle toe with claw, the planta tarsi covered with hexagonal or rhom- 

 boidal scales, of which the more posterior (on both sides) are larger, 

 more transverse, and form a more or less continuous row. 



Plumage and coloration. — Crest bushy, occupying whole of pileum, but 

 its central feathers longest, these rather soft, broad with rounded tips, 

 their webs not conduplicate ; contour feathers with very sharply defined 

 regularly convex outlines, especially on neck, chest, and breast. Head 

 light grayish brown, the crest tipped with dull white ; neck and chest 

 light bluish gray, the feathers (those of breast also) sharply margined 

 with black, producing a conspicuous squamated effect ; upperparts plain 

 light brownish gray or drab, the inner webs of tertials edged with buff or 

 buffy whitish. Sexes alike in coloration. 



Range. — Mexican plateau and contiguous portion of United States, 

 from southern Texas to Arizona. (Monotypic. ) 



KEY TO THE FORMS OF CALLIPEPLA SQUAMATA (VIGORS) 



a. Scapulars and upper surface of wings deep grayish brown; posterior lower parts 

 deep buffy to ochraceous; the abdomen with an extensive patch of rusty chest- 

 nut in the male and usually with an indication of it in the female (south-central 

 Texas to northeastern Mexico) . .Callipepla squamata castanogastris (p. 269) 

 aa. Scapulars and upper surface of wings pale grayish brown or brownish gray; 

 abdomen pale buffy or whitish; usually without trace of chestnut in either sex. 

 b. Breast and upper back plumbeous-gray, lower back and rump dusky olive- 

 brown abdomen, especially in the male, strongly suffused with yellowish 

 brown (Valley of Mexico from southern Coahuila south to near City of 



Mexico) Callipepla squamata squamata (p. 270) 



bb. Breast and upper back pale dull gray ; lower back and rump dull, pale olive- 

 brown ; abdomen cream-buff to buff, not suffused, in either sex, with yellow- 

 ish brown (Arizona, New Mexico, and western Texas, south to northwestern 

 Mexico) Callipepla squamata pallida (p. 265) 



CALLIPEPLA SQUAMATA PALLIDA Brewster 



Arizona Scaled Partridge 



Adult (sexes alike in coloration). — Forehead and crown between light 

 buff and pale ochraceous-buff , often with a grayish wash ; center of crown 

 with a short, bushy crest, the anterior feathers of which are wood brown 

 to buffy brown, the posterior ones paler, all broadly tipped with white; 

 feathers of occiput and posterior sides of neck pale grayish with a buffy 

 tinge, barred with narrow bands of dark wood brown ; nape and inter- 

 scapulars gull gray, each feather narrowly tipped with fuscous to chaetura 

 drab ; upper wing coverts, upper back, and scapulars pale olive-brown 

 washed with gull gray and tipped with slightly darker olive-brown ; back, 

 rump, and upper tail coverts similar but with a grayish wash; sec- 

 ondaries drab, their inner webs edged with buffy white and narrowly 

 tipped with the same; primaries uniformly drab; upper tail coverts pale 

 drab washed with gull gray ; rect rices between mouse gray and light mouse 



