180 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



constantly from aestiva of eastern North America in liavinf the chestnut 

 streaks on the under parts narrower and fainter —in this respect showin" an 

 approach to sonorana, fiom which, however, it may be readily distinguished by 

 the decidedly darker, greener coloring of its upper parts. The female is similar 

 to aestiva (although less often streaked beneath) and hence quite different 

 from that of sonorana, which is grayish above and clay-colored beneath, with 

 but faint traces of yellowish on the body plumage. On the whole the Yellow 

 Warbler of California seems to me too nearly like true aestiva to be recognized 

 as a distinct subspecies. In any case it should not be called viorcomi. At 

 least Mr. Ridgway and I agree in considering the type of that supposed form 

 merely an exceptionally faintly streaked specimen of aestiva, of which, more- 

 over, the National Museum possesses a number of perfectly typical examples 

 from the same general region (i. e. Utah and Montana) one of them being 

 actually from the same locality (Fort Bridger). 



Mr. Frazar found the Yellow Warbler rather rare in January and February 

 at La Paz, where it frequented the shrubbery in the town gardens. It was not 

 noted after March 1 (save on April 21, when one was seen at Triunfo) until 

 August 28, when it was again met with at San Jose del Cabo. Here it became 

 common by the latter part of September, but it kept so closely concealed in 

 dense thickets as to be much oftener heard than seen. A single specimen was 

 also taken at Santiago on November 16. To the northward of La Paz it does 

 not seem to have been observed by any one except Mi*. Anthony, who " says 

 it is common on the northwest coast up to 2,500 feet altitude " (Bryant), 

 and " common during migration in the valleys and as a summer resident in the 

 higher altitudes," on San Pedro Martir.^ 



The Yellow Warbler breeds plentifully on the Pacific coast from southern 

 California to Washington, being replaced in British Columbia and to the north- 

 ward ])y the closely allied subspecies, rulmjinosa. It is not known to occur 

 north of the southern boundary of the United States during the winter months, 

 when it migrates to Central America and the more northern portions of South 

 America. 



Dendroica aestiva sonorana Brewst. 



SoNORA Yellow Warbler 



(?) Dendroeca aestiva Belding, Proc. U. S. Nat. Mus., V. 1883, 536, part (Cape 



Region). 

 (?) Dendroica aestiva Bryant, Proc. Calif. Acad. Sci., 2d ser., II. 1889, 309, part 



(Cape Region). 



Among the Yellow Warblers collected by Mr. Frazar there are, as I have just 

 stated in another connection, four young females killed at San Jose del Cabo — 

 on October 5, 12, 20, and 27 respectively — which are perfectly typical speci- 



1 Anthony, Zoe, IV. 1893, 244. 



