1920] 



Swarth: Revisio7i of Avian Genus Passerell<i 



99 



Fig. D. Map of California and portions of Oregon and Nevada, shmving, by 

 conventionalized drawings of heads, the varying development of the bill in the 

 subspecies breeding in the region. The position of the figures indicates approx- 

 imately the summer habitat of each of the several forms, a, schistacea; h, fulva; 

 0, hrevieauda; d, canescens; e, monoensis; f, mariposae; g, stepheiisi. 



