72 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



So, on the whole, the series may safely be considered as 

 representing the form breeding in this same general region. 

 In coloration the whole series is quite uniform and but slightly 

 distinguished from charienturus, being more nearly like this 

 race than like Sacramento Valley drymoecus. In measure- 

 ments the birds stand about midway between the two forms, 

 though rather nearer the latter (see table). All things consid- 

 ered, I have regarded these birds as illustrating intergradation 

 between typical drymoecus and charienturus, and as represent- 

 ing about the extreme southern valley locality which the name 

 drymoecus may be used to cover. 



Sierra Nevada. There are six spring birds from Nevada 

 County. Two are from Montezuma Hill, taken March 30, 

 and four from Cherokee, April 5 and 7. From these dates 

 they may fairly be assumed to be representative of the breed- 

 ing bird of the region. In coloration they closely approach 

 Sacramento Valley drymoecus, though they are not quite so 

 reddish; in measurements and proportions there is no dif- 

 ference. 



There are at hand four immatures in fresh winter plum- 

 age : a male, Blue Canyon, Placer County, October 21 ; two 

 males and a female, Carroll Creek, east slope of Sierra Ne- 

 vada in Inyo County, September 11 and 12; all collected at 

 altitudes from 5000 to 7500 feet. A difficulty arises in the 

 proper weighing of the characters of these birds, in that they 

 were evidently late summer wanderers from lower altitudes, 

 from just where, it is impossibfe to say. 



The Blue Canyon specimen (Mus. Vert. Zool., no. 23,295) 

 is dark reddish above, widely different from autumnal charien- 

 turus, but not so readily distinguished from fall specimens of 

 marinensis. It is presumably typical of the fall plumage of 

 drymoecus as occurring in the central Sierra Nevada. The 

 three birds from Carroll Creek (Mus. Vert. Zool., nos. 20,858, 

 20,859, 20,866) are quite different in appearance. They are 

 but slightly reddish above, and with a grayish cast not seen 

 either in charienturus or in typical drymoecus. As to the pre- 

 cise region occupied by these latter birds during the breeding 

 season, that, of course, is problematical, for they might have 

 wandered even from over the crest of the Sierras; but their 

 appearance leads to the assumption that they represent an ex- 



