112 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



fess an inability to distinguisli between specimens from the two conti- 

 nents, and therefore insist upon their identity, althongh some of the 

 best anthorities rank G. mcxicana as a distinct species. 



For the pnrpose of carefully reviewing the subject in all its bearings, 

 I hare brought together a considerable number of specimens, and after 

 a very deliberate comparison of this material (embracing many skins 

 not inclnded in the following tables of measurements), and an equally 

 careful consideration of all that has been written on the subject, I am 

 forced to the conclusion that the G. mexicana itself cannot stand even 

 as a race, or else it becomes necessary to recognize a larger nnmber 

 of races than have usually been claimed for the species. In other 

 "words, it is simply a question of whether geographical variations of 

 form and colors are to be completely ignored as a factor in the genesi* 

 of species, or whether they should receive due consideration in connec- 

 tion with this important subject. Believing the latter view to be the 

 more scientific one, and since they are each "associated with definite 

 geographical areas," 1 find the following races suscei)tible of definition. 



A. — Primary coverts disfinctly tipped with whitish. 



1. familiaris Linn. (Ijased iipon Scautlinavian speeimeus). 



Of this form I have three examples before me from Bergen, Norway 

 (coll. L. Stejneger). These agree in having the lower parts of a brilliant 

 silvery white, never seen in American specimens, thongh this pure white 

 color is somewhat obscured by a grayish tinge nndoubtedly caused by 

 contact with carbonaceous substance upon burnt trees. The cri^snm is 

 very faintly tinged with butf ; the lores are either wholly white or else 

 merely tinged with dusky in front of the eye; the dark ground color of 

 the upper parts is much tinged with yellowish tawny (which prevails on 

 the rump), and the maxilla is either very dark brown or black. These 

 specimens measure as follows : 



2. ?cost8e Bailly (described from Savoy). 



I have five examples from central Enrope, which may be readily dis- 

 tinguished from the Scandinavian specimens described above. The 



