Appendix, 



the back spotted with whitish and the breast 

 mottled with white and brownish. Resident in 

 the foothills and lower mountains of California, 

 wintering in the valleys. 



204. Mountain Bluebird; Sialia arctica (Swains. ) . 



Size of the preceding or a trifle larger. Male, 

 above and below a beautiful azure, much lighter 

 in tone than the preceding bird; paler on under 

 parts, changing to white on the belly. Female, 

 above brownish gray, changing to bluish on 

 wing-quills, rump and tail; below paler, chang- 

 ing to white on belly; tips of wings blackish 

 brown. Breeds in the Sierra Nevada Moun- 

 tains, migrating in winter to the valleys, chiefly 

 in the interior. 



