Vol. XT 

 i893 J 



Rhoads, Washing-ton and British Columbia Birds. 



J 9 



East Cascade region of B. C. 



West Cascade region of B. C 



West Cascade region of Washington 



* " 



Average 



Average of C. americanus (Eastern) 



Examination of these figures and of the specimens from which they are 

 taken emphasizes the conclusions of Mr. Chapman (based on the Streator 

 series), as given in the Bulletin of the Amer. Mus. Nat. Hist., Vol. Ill, p. 

 142. "Coloration is apparently of no diagnostic value — examples which 

 measurements proclaim caicriuus are as glossy as any of the larger birds, 

 while some of these [larger specimens] are as lustreless as any bird in the 

 series." It is also remarkable that extremes of the series, referable to 

 caurinus on the one hand, and to americanus on the other, are connected 

 by an unbroken chain of intermediates exhibiting every possible phase of 

 gradation, inhabiting promiscuously certain parts of the same breeding 

 range, and that in three localities the extremes were found paired 

 together. 



