116 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



h. — Primary coverts untliout whitish tqys. 



7. mexicana Gloger. 



Guatemala and southeru Mexico. 



Tliis form differs conspicuously from all tbe others iu tlie total absence 

 of light tips to the primary coverts. The lower parts are also decidedly 

 grayish, with only the throat and chin white, the rumj) a bright chest- 

 nut-rusty, and the ground-color of the anterior upper ijarts a blackish- 

 brown, with the lighter streaks of a rather grayish tone. In slender bill 

 and other features of form it scarcely differs from the more northern 

 races, montana and occidentalis, and is by no means smaller, thus afford- 

 ing another of the very numerous ''exceptions" to the supposed law of 

 smaller size to the southward of resident species.* The three specimens 

 which I have been able to examine measure as follows: 



SiHTHSONiAN INSTITUTION, March 23, 1882. 



* In perhaps a majority of cases where I have recently te.sted the matter by measure- 

 meiit.s of Large series of many Passeres I have heeu imable to verify this sui)posed law 

 of latitudinal variation in size. 



