FAM. L. DUCKS, GEESE, AND SWANS 285 



B. Bill peculiarly bulging at base ; '^ nail large and so united with the bill 



as to give the nail a very indistinct outline. (J.) 

 B. Bill appendaged with a lobe at base formed of the skin of the cheeks ; * 



culmen about 1 long ; speculum 6 violet 20. Harlequin Duck. 



B. Bill appendaged with a leathery expansion at the sides near tip ; cul- 

 men over 1-1 long ; speculum white. The Labrador Duck (156. Camp- 

 tolalmus labradbrius) might possibly be found, though it is thought 

 to be extinct. 

 B. Bill of the usual duck form. (C.) 



C. Tail pointed (over 6 long, male; about 3 long, female); bill black 

 and orange ; nostril within less than \ inch of frontal feathers . . . 



19. Old Squaw. 



C. Nostril about \ inch from frontal feathers ; nail of bill narrow and 

 distinct. (D.) 

 D. Bill high at base (over | as high as long) ; under tail coverts white. (I.) 

 D. Bill not so high at base ; under tail coverts dark. (E.) 

 E. Bill decidedly wider near tip than at base. ^ (G.) 

 E. Bill with the width near tip about the same as at base (in any case 

 less than \ inch wider). (F.) 



F. Bill about | as wide as the length of culmen 11. Redhead. 



F. Bill about \ as wide as long 12. Canvas-back. 



G. 3Iale with an orange ring around neck ; speculum " bluish-gray ; 



female chiefly brown 15. Ring-necked Duck. 



G. Male with white speculum ; female with white face. (H.) 



H. Wing over SJ long 13. American Scaup Duck. 



H. Wing under 8J long 14. Lesser Scaup Duck. 



I. Hale with gloss of the almost black head and throat green ; female 



with a brown head 16. American Golden Eye. 



I. Male with the gloss of the dark head and throat purple ; female 



with a brown head 17. Barrow's Golden Eye. 



J. Wing, 10| or more long ; a white wing patch in both sexes 



25. White-winged Scoter. 



J. Wing less than 10^ long. (K.) 

 K. Culmen, 1| or more long ; the feathers on the culmen reaching 

 about as far forward as those on the sides of the upper mandible 



24. American Scoter. 



K. Culmen less than If long ; feathers on the culmen reaching about 

 an inch farther forward than those on the side of the upper man- 

 dible 26. Surf Scoter. 



L. Feathers on the culmen extending forward much farther than those 

 on the side of the upper mandible 23. King Eider. 



