234 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



dd. Larger (wing of male ad. 73.15-79.40, tail 88.90-93.98); back slightly 

 grayer and tail less rufescent. (State of Oaxaca, southern Mexico.) 



AimopMla rnficauda lawrencii (p. 239) 

 cc. Chest pure white or but faintly tinged or clouded with gray. (Southwestern 



Jlexico.) Aimophila acuminata (p. 240) 



aa. Anterior under parts neither pure white, white with black or gray across chest, 

 nor gray with black on throat; pileum chiefly brown or rusty, without any 

 distinct or sharply defined median band of white or grayish. 

 b. Lesser wing-coverts cinnamon-rufous; maxilla cinnamon-brown. 

 r. Larger, with much larger bill (wing of adult male averaging 68.83, tail 68.33, 

 culmen always more than 12.70, tarsus 20.32 or more); upper tail-coverts 

 cinnamon or russet. (State of Oaxaca, southwestern Mexico.) 



Aimophila samiclirasti (p. 240) 

 cc. Smaller, with much smaller bill (wing of adult male averaging 63.25, culmen 

 always less than 12.70, tarsus less than 20.32); upper tail-coverts and tail 

 brownish gray. (Southern Arizona and northern Sonora.) 



Aimophila carpalis (p. 241) 

 66. Lesser wing-coverts brown or grayish (sometimes tinged with yellow near car- 

 pal joint) ; maxilla blackish, 

 c. Mandible, as well as maxilla, black; lateral crown-stripes Vandyke brown. 



(Highlands of Oaxaca, southern Mexico. ) Aimophila notoaticta(p. 242) 



cc. Mandible bluish gray or otherwise light-colored; -lateral crown-stripes (or 

 whole pileum) chestnut or rufous, or streaked brown and grayish. 

 d. Pileum chestnut or chestnut-rufous; edge of wing white. 

 e. Larger (wing 71.12 or more, tarsus more than 22.86). 

 /. Bill stouter (depth at base 10.16 or more); pileum more extensively 

 chestnut; coloration in general darker, above more rusty with differ- 

 ently colored areas more strongly contrasted. 

 g. Darker; pileum deep chestnut, usually with a distinct median stripe 

 of grayish or dull buffy and streaked with black, especially later- 

 ally and posteriorly; back browner and more distinctly streaked. 

 (Southern Mexico to Honduras.) 



Aimophila rnfesceus rafescens (p. 243) 



gg. Paler; pileum light chestnut without distinct median pale stripe 



or black streaks; back more rusty and less distinctly streaked. 



h. Wing and tail shorter, bill longer; coloration more rusty above, 



less buffy beneath; wing less than 76.20, tail not more than 77.47, 



exposed culmen not less than 15.24. (Southwestern portion of 



Mexican plateau.) Aimophila rafescens pallida (p. 245) 



hh. Wing and tail longer, bill shorter; coloration grayer above, more 

 buffy beneath; wing 77.47, tail 83.82, exposed culmen 14.73. 

 (Coast district of Sinaloa. ). Aimophila rnfesoena sinaloa (p. 245) 

 ff. Bill more slender (depth at base less than 10.16); pileum less exten- 

 sively chestnut (this mostly confined to anterior portions) ; coloration 

 in general paler, above grayer, with differently colored areas less 

 strongly contrasted. (Northwestern Mexico.) 



Aimophila mcleodii (p. 246) 

 e. Smaller (wing less than 71.12, tarsus less than 22.86). 

 /. General aspect above rufescent, or at least with very broad streaks of 

 chestnut-browTi or rusty on back. 

 g. Smaller (wing averaging less than 60.96, tail averaging less than 

 63.50). 

 h. Coloration duller, with white of orbital ring, etc., duller; bill more 

 slender. (California.) Aimophila ruflceps raflceps (p. 246) 



