32 KEY TO DUCKS, OEESE AND SWANS OF NORTH AMERICA. 



GROUP VI. 



Birds having wings from 12 to 14 inclies long.* 



Section 1. Head not black or marked with black. 



Head, dark, glossy green; white ring around neck ; speculum, bluish purple, 

 edged with black and white. 



nallard Duck. 



Anas boschas (male) . 

 See page 41. 



Head, brownish ; general plumage, mottled brown ; speculum, bluish purple 

 edged with black and white. 



nallard Duck. 



Anas Boschas (female) . 

 See page 41. 



Head, brownish ; general plumage, brown, streaked with buff and dark brown; 

 speculum, bluish purple not edged with white. 



Black Duck. 

 Dusky Duck. 



Anas obscura. 

 See page 42. 



General plumage, white; head, white, sometimes tinged with brownish orange 

 (adult). General plumage, grayish (immature). 



Ross's Snow Goose. 



Chen rossii. 



See page 82. 



Section 2. Head marked with more or less black, or 



entirely black. 



Head, black, divided on crown ; more or less pale green on head ; throat, white, 

 marked with black V ; no speculum. Pacific coast. 



Pacific Eider Duck. 



Somateria V-nigra (male). 

 See page 70. 



For directioDB for wing measurements, see page 6. 



