114 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



otlier measurenieuts are on the average quite different. In coloration, 

 they most resemble G. cosUv, hut as a rule have the the crissum more 

 decidedly buff, and the rump brighter tawny, while the maxilla is never 

 light brown, as often occurs in the South-European form. The follow- 

 ing measurements are from fully adult birds, in perfect plumage: 



5. montana Subsp. vov. 



Middle Province of North America; (uortli to Kadiak, Alaska) breeding south to 

 New Mexico and Arizona, in wooded mountains. 



While I have been able to examine a smaller series of this form than 

 any other except familiaris proper and byittanica, the six examples in- 

 spected show such well-marked peculiarities of form and coloration as 

 to leave no doubt of the propriety of separating the Rocky Mountain 

 bird as a geographical race. The general tone of coloration is decidedly 

 grayer above than in any other form of the species, the flanks are de- 

 cidedly grayish, the crissum more pronounced buff than in either of the 

 three European races, and the tawny of the rump in more abrupt con- 

 trast with the grayish of the back. The most decided differences, how- 

 ever, are in proportions: thus, while the wing averages shorter than in 

 either Jam 11 iar is or cost(v, the tail is decidedly longer; the bill also aver- 

 ages much longer than in famiUaris or cosUc, but is altogether more 

 slender, both the vertical height and the transverse thickness being 

 much less. As is the case with all the American races, the hallux and 

 hind claw — the latter especially — are almost constantly shorter than in 

 the European forms. 



