170 University of California Publications in Zoology [Vol. 21 



The southern California winter specimens do not suffice to indicate 

 the winter habitat of this subspecies. Apparently, however, canescens, 

 like the other Sierran and Great Basin forms, avoids the vicinity of 

 the coast, and must be looked for farther inland. The points of 

 winter capture here recorded may indicate the northern and western 

 limits at that season. 



It is a noteworthy fact that in all the bird collecting carried on 

 by the Museum of Vertebrate Zoology in Owens Valley and in the 

 Death Valley region, not a single migrating example of canescens 

 was secured. As these places are directly south of the White Moun- 

 tains, they would certainly be traversed by migrating canescens, unless 

 — as seems probable — the birds pass over these regions in long, direct 

 flights toward and from the winter habitat. Accumulating data points 

 more and more convincingly toward this latter mode of travel as 

 prevalent among many of the subspecies of Passerella. 



Passerella iliaca monoensis Grinnell and Storer 

 Mono Fox Sparrow 



Original description. — Passerella iliaca monoensis Grinnell and Storer, 1917, 

 p. 165. 



Type specimen. — No. 26930, Calif. Mus. Vert. Zool. ; male adult; 

 Mono Lake Post Office, altitude 6500 feet, Mono County, California; 

 May 21, 1916 ; collected by Joseph Dixon ; original no. 4644. 



Range. — Breeds on the east slope of the Sierra Nevada in the 

 vicinity of Mono Lake ; possibly also in the Panamint Mountains. 

 Occurs in winter in the western foothills of the Sierra Nevada and on 

 the Pacific slope of southern California. 



Specimens examined. — 38 (see list, p. 206). 



Distinguishing characters. — Of the Schistacea group (see p. 89). 

 A gray-colored fox sparrow, in bill character intermediate between 

 canescens and mariposae (see fig. E). Of the pale coloration common 

 to the cnnescens-m,onoensi'S-m>ariposae-stephensi series. In this line of 

 subspecies monoensis occupies a position comparable to that of fulva 

 in the schistacea-fulva-megarhynchus-hrevicauda chain. Specimens of 

 monoensis and fulva are sometimes very much alike in bill structure, 

 but may be distinguished by coloration, fulva being a brownish colored 

 bird, monoensis a grayish colored one. 



Remarks. — There is a fox sparrow at hand, an adult male in rather 

 worn plumage, collected at Jackass Springs, Panamint Mountains, 

 California, June 25, 1917 (no. 28430, Mus. Vert. Zool.) that I tenta- 

 tively refer to monoe^isis. The capture of this specimen in midsum- 

 mer, a bird which was in full song and in breeding condition, is fair 



