Synopsis of the Genus Thryomanes 25 



couver Island, kindly loaned from the collection of the 

 Museum of Vertebrate Zoology, by Dr. Joseph Grinnell, 

 average a very little lighter, particularly on the upper 

 parts, than birds from the Puget Sound region, which lat- 

 ter represent the most extreme development of dark color 

 in this subspecies; and to this variation Mr. H. S. Swarth 

 has already called attention.^ There seems, however, to be 

 no difference between birds from Vancouver Island and 

 those from southwestern Washington and the coast of Ore- 

 gon, which, therefore, would have to be referred to the same 

 subspecies were any separation made of the birds from Van- 

 couver Island. The ditferences exhibited by the latter, 

 however, are in our opinion, too slight and too much af- 

 fected by individual variation to warrant subspecific recog- 

 nition, and we therefore think Mr. Swarth quite right in 

 refraining from giving the bird from Vancouver Island a 

 name. 



Thryomanes bewickii ariborius^ subsp. nov. 



Chars, suhsp. — Similar to Thryomanes 'bewickii calo- 

 phonus, but upper parts decidedly lighter and of a more 

 rufescent brown, and the flanks also more rufescent. 



Description. — Type, adult female. No. 136701, U. S: 

 National Museum, Biological Survey Collection; Agassiz, 

 British Columbia, December 5, 1895; C. P. Streator. Up- 

 per parts between Front's brown and cinnamon brown, but 

 the rump with concealed roundish silver white spots; cen- 

 tral tail-feathers dark hair brown, more rufescent and 

 about the color of the back basally, and regularly though 

 narrowly barred with brownish black; remainder of the 

 tail fuscous black, the outer webs of the rectrices with nar- 

 row bars of brownish black and wide bars of rufescent hair 

 brown, these bars confined on the outer feathers to the 

 basal portion but continuing throughout on the inner 

 feathers; and the two pairs of feathers next to the middle 

 pair with broad tips of light hair brown, the remaining 



^Proc. Calif. Acad. Sci., ser. 4, VI, No. 4, May 8, 1916, p. 60. 



