BAY AND SEA DUCKS 199 



a 1 . Back black; bill with a bluish band near its tip. 



150. RING-NECKED DUCK <?. 

 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 d". 



b 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. 



6 1 . Head and neck rufous or rufous-brown, sharply defined from 

 the black breast. 



6 2 . Head and upper neck rich rufous; bill 2*00 or under; flanks 



finely barred, like the back 146. REDHEAD d". 



6 3 . Head and neck rufous-brown; crown blackish; bill over 2*00; 



flanks very slightly if at all barred . . 147. CANVASBACK d\ 

 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 9 . 



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 TOO or 

 more in height 152. BARROW'S GOLDEN-EYE d". 



a 2 . Head and throat steel-green; white patch at base of bill less 

 than TOO in height 151. AM. GOLDEN-EYE d". 



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. 

 6 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". 



d z . 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 d". 



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 biP 166. SURF SCOTER 9. 



e 6 . Feathers on culmen reaching Jittle of any beyond 



those at sides of bill . . , t . . 163. AM. SCOTER 9, 



<*, Bill under 1'25, 



