. LX. 139 



hhhh. Ducks with none of the above peculiarities. 

 t. Upper mandible gibbous at its unfeathered base; black 

 or brown. . . . . . CEDEMIA, 19. 



it. Upper mandible not gibbous where unfe.athered. 

 j. Nail at tip of bill narrow and distinct. 



A:. Head black or brown; nostrils sub -basal; bill 

 longer than tarsus. . . . FULIX, 12. 



kk. Head reddish or brownish, without white ; nos- 

 trils nearly median ; bill longer than tarsus. 



AYTHYA, 13. 



kkk. Head black or gray, with white ; nostrils nearly 

 median ; bill about as long as tarsus. 



CLANGTJLA, 14. 

 jj. Nail broad, scarcely distinct. 



I. Feathers extending on culmen and partly on sides 



of upper inaudible. . . SOMATERIA, 18. 



tt. Feathers not extending on culmen ; bill small, 



much tapering. . . HISTRIONICUS, 17. 



ff Bill narrow, nearly cylindrical; the lamellae acute, recurved, 



like saw-teeth ; usually crested. Fish Ducks. (MERGING.) 



m. Bill not black ; tarsus more than half the length of middle 



toe ......... MERGUS, 21. 



mm. Bill black ; tarsus half length of middle toe. 



LOPHODYTES, 22. 



/. CYGNUS, Linnreus. SWAXS. 

 > Olor, Wagler. 



1. C. buccinator, Rich. TRUMPETER SWAX. Tail 

 (normally) 24 feathered; bill without yellow spot, longer 

 than head; nostrils sub -basal; L. about 50. Miss. 

 Valley, W. and N. 



2. C. columbianus, (Ord.) Coues. WHISTLING SWAX. 

 Tail 20 feathered; bill with a yellow spot, not longer 

 than head; nostrils median; L. 50. N. Am. (C.ameri- 

 canus, Sharpless.) 



