BIRDS OF NORTH AND MIDDLE AMERICA, 325 



(id. Sides of chest not exteusively, if at ail, blue, ajid feathers of lower uiedian 



portion of chest whitish, witli indisitinct grayi.sh edges. 



('. Larger (achilt male averaging wing 148, tail 147, exposed culmen 27, 



tarsus 43); n(j distinct white superciliary streak. (Southern portion of 



Mexican plateau, in States of Tlaxcala, Vera Cruz, Puebla, and Oaxaca.) 



Aphelocoma sumichrasti {\). 336) 

 ee. Smaller (adult male avi-raging wing not more than 11!:!. 5, tail 140, exposed 



culmen 27.5, tarsus 40.5); .a distinct white superciliary streak. 

 ■ /". Darker, the blue of a light cobalt or azure hue, back and breast dis- 

 tinctly brownish gray; bill and feet much stouter (exposed culmen of 

 adult female averaging 26, depth of bill at base 9.5, tarsus 39.5). 

 (Southwestern Texas, from Davis Mountains east to Kerr Coimty.) 



Aphelocoma tezana (p. 337) 

 ff. Paler, the blue of a light grayish cerulean hue, back and breast ashy 

 gray; bill and feet much more slender (exposed culmen of adult 

 female 25, depth of bill at nostrils 8, tarsus 38). (Southern Chi- 

 huahua. ) Aphelocoma grisea ( p. 337) 



hh. Tail decidedly shorter tlian wing; no streaks on throat or chest, the under 

 parts being plain grayish, deeper on chest, paler (often white) i)Osteriorly. 

 r. Tail distinctly rounded at tip. (Aphelocomd xiehcrii.) 



(}. Larger (wing of adult male averaging more than 1H5, tail averaging more 

 than 146). 

 I'. Brighter colored,, the pileum, hindueck. wings, upjier tail-coverts, and 

 tail distinctly blue. 

 /. Darker, the blue of a cobalt hue; jMjsterior under ]>arts pale grayish, 

 even the under tail-coverts at least i)artly gray. ( Southern i)ortion of 

 Mexican plateau, in States of Vera Cruz, Puel)la, southern Hidalgo, 

 Mexico, Morelos, and ^[ichoacan. ) .Aphelocoma sieberii sieberii (p. 338) 

 ff. Paler, the blue of a cerulean hue; ])osterior under parts white, the under 

 tail-coverts pure white or with the longer ones Imt slightly grayish. 

 //. Larger, except bill and feet (wing of adult n)ale averaging 178, tail 

 158.5); breast, etc., nujre brownish gray. (Southwestern i)art of 

 Mexican plateau in States of Jalisco and Colima. ^ 



Aphelocoma sieberii colimae ( p. 339) 



f/f/. Smaller, except bill and feet (wing of adult male averaging 167, tail 



146.5); breast, etc., more bluish gray. (Northeastern portion of 



Mexican ])lateau, in States of Tlidalgo, eastern San Luis Potosi, 



southern Tamaulipas, southern Coabuila, and eastern Zacatecas.) 



Aphelocoma sieberii potosina (p. 340) 



ee. Duller colored, the pileum, hindneck, wings, tail, etc., dull grayish blue. 



(Southern Arizona and New- Mexico; northern Chihuahua and Sonora. ) 



Aphelocoma sieberii arizonae (p. 340) 



dd. Smaller (wing of adult male averaging less than 15S.5, tail averaging less 



than 139.5). 



e. Larger, with smaller bill (wing of adult male averaging 158, tail 136, 



exposed culmen 26.5, depth of bill at nostrils 9.5); coloration slightly 



paler. (Northwestern and central jiortion of Mexican plateau, in States 



of western San Luis Potosi, Zacatecas, northern Jalisco, southwestern 



Chihuahua, and Sinaloa. ) Aphelocoma sieberii woUweberi (p. 341 ) 



ee. Smaller, with larger bill (wing of adult male averaging 146, tail 126.5, 

 exposed culmen 29, depth of bill at nostrils 10); coloraticm slightly 

 deeper. (Northeastern ^lexico, in State of Nuevo Leon and north to 



Chisos Mts., southwestern Texas.) 



Aphelocoma sieberii couchi (p. 342) 



cc. Tail even or truncated at tip. ("Mexico.") .Aphelocoma ultramarina (p. 343) 



