654 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



decurved; maxillary tomium faintly concave, more decidedly so termi- 

 nally, where without trace of notch; gonys much shorter than dis- 

 tance from nostril to tip of maxilla, straight or almost inappreciably 

 concave terminally; depth of bill at frontal antise less than its width 

 at same point. Nostril longitudinal, linear, with a distinct corneous 

 excurrent operculum, its posterior end nearly or quite in contact with 

 latero -frontal feathering. Rictal bristles obsolete. Wing moderate 

 or rather long; seventh and sixth primaries longest, the eighth and 

 fifth but little shorter; ninth about equal to first and nearly twice as 

 long as tenth. Tail about six-sevenths as long as wing, nearly three 

 times as long as tarsus, slightly rounded, or nearly even with lateral 

 pair of rectrices considerably shorter than the rest. Tarsus decidedly 

 longer than middle toe with claw, the acrotarsium distinctly scutel- 

 late, the planta tarsi sometimes with several divisions, obvious only on 

 close inspection; lateral toes of unequal length, the inner (without 

 claw) reaching only to middle (subterminal) joint of middle toe, the 

 outer (without claw) reaching to middle of subterminal phalanx of 

 middle toe, its claw reaching to base of middle claw; hallux (without 

 claw) slightly shorter than outer toe, slightly longer than inner, its 

 claw much shorter than the digit; all the claws grooved on both sides 

 (as in HylorcKilus)\ basal phalanx of middle toe adherent to outer toe 

 for entire length, to inner toe for most of its length. 



Coloration. — Above grayish brown, becoming more rusty poste- 

 riorly, the tail cinnamon-rufous, crossed by distant bars of black; 

 back, etc., more or less speckled or dotted with dusky and whitish; 

 chin, throat, and chest white; rest of under parts rustj', more or less 

 speckled or dotted with whitish and dusky. 



Nidification. — Nest in holes, usually among rocks, sometimes in 

 buildings; eggs white, speckled with reddish brown. 



Range. — Arid portions of western United States and Mexico. 

 (Monotypic.) 



KEY TO THE SUBSPBCIBS OF CATHERPES MEXICANUS. 



a. Darker, the general color of upper parts sepia brown (tinged with chestnut on 



back and rump), the abdomen, etc., rich chestnut; black bars on tail broader. 



6. Larger and darker; adult male averaging, wing 68, tail 56, exposed culmen 23.9, 



tarsus 20; adult female, wing 63.1, tail 53.2, exposed culmen 21.6, tarsus 19.2. 



(Southern and central parts of Mexicain plateau.) 



Catherpes mexicanus mexicanus (p. 655) 

 66. Smaller and paler; adult male averaging, wing 58.1, tail 51.6, exposed culmen 

 20.5, tarsus 18.6; adult female, wing 56.2, tail 47.8, exposed culmen 20, 

 tarsus 17.7. (California, except southeastern and extreme southern por- 

 tions. ) Catherpes mexioanus punctnlatus (p. 659) 



aa. Paler, the general color of upper parts light grayish brown (mor^ rufescent on 

 back and rump), the abdomen, etc., lighter chestnut; black bars on tail 

 narrower. 



