BAY AND SEA DUCKS 
199 
a 1 . Back black; bill with a bluish band near its tip. 
150. Ring-necked Duck d”. 
6 1 . Back finely barred with black and white. 
b 2 . Back of head generally with purplish reflections; wing gener- 
ally under 8*25; nail of bill generally under *25 in width. 
149. Lesser Scaup Duck <?. 
5 3 . Back of head generally with greenish reflections; wing gener- 
ally over 8*25; nail of bill over *25 in width. 
148. Greater Scaup Duck <?, 
b. Head and neck not black. 
b 1 . Head and neck rufous or rufous-brown, sharply defined from 
the black breast. 
b 2 . Head and upper neck rich rufous; bill 2*00 or under; flanks 
finely barred, like the back 146. Redhead <?. 
b 3 . Head and neck rufous-brown; crown blackish; bill over 2*00; 
flanks very slightly if at all barred . . 147. Canvasback . 
c 1 . Head and neck brownish or grayish. 
c 2 . A white patch in the wing. 
c 3 . Feathers at base of bill white; wing generally under 8*25; 
nail of bill generally under *25 in width. 
149. Lesser Scaup Duck $ . 
c 4 . Feathers at base of bill white; wing generally over 8*25; 
nail of bill generally over *25 in width 
148. Greater Scaup Duck 9 . 
d 2 . No white in wing. 
d 3 . An indistinct bluish band near the tip of bill; bill under 2*00. 
d 4 . Wing under 8*00 150. Ring-necked Duck 9. 
d 5 . Wing over 8*00 146. Redhead 9. 
e 3 . No band on bill; bill over 2*00 . . . 147. Canvasback 9. 
B. Axillars and most, if not all, the under wing-coverts blackish. 
a. Head and throat dark steel-blue or steel-green. 
a 1 . Head and throat steel-blue; white patch at base of bill 1*00 or 
more in height 152. Barrow’s Golden-eye d 1 . 
a 2 . Head and throat steel-green; white patch at base of bill less 
than 1*00 in height 151. Am. Golden-eye cf. 
b. Head and throat not steel-blue. 
b 1 . Whole head and throat brown, sharply defined from the gray 
or white neck; a white patch (speculum) in the wing. 
b 2 . Nostril nearer the tip than the base of the bill. 
151. Am. Golden-eye 9. 
b 3 . Nostril in the middle of the bill. 
152. Barrow’s Golden-eye 9. 
c 1 . Head and throat not brown but with more or less black. 
c 2 . Whole head ’and neck black. 
c 3 . Plumage black 163. Am. Scoter <?. 
d 2 . Whole head and neck not black. 
d 3 . Crown-patch or cheeks white. 
d 4 . A white patch on the top of the head and another on 
the nape 166. Surf Scoter d 1 . 
d 5 . Middle of crown black, bordered by chestnut; front 
half of face white 155. Harlequin Duck <?. 
e 3 . Head and neck whitish, grayish, or brownish, no white in 
wing. 
e 4 . Bill over 1*25. 
e 5 . Feathers on culmen reaching much farther forward 
than those at sides of the bill . 166. Surf Scoter 9. 
e 6 . Feathers on culmen reaching little of any beyond 
those at sides of bill 163. Am. Scoter 9. 
/ 4 . Bill under 1*25* 
