284 



WATER FOWL. 



b. Head without elongated crest. 



a' . Bill long as middle toe without claw, 

 greatest width less than one-third the 

 length of culmen. Head long, not 

 bunchy. 



b' . Bill shorter than middle toe without 

 claw, greatest width more than one- 

 third the length of culmen. Head 

 bunchy. 



c'. Bill shorter than head, broad, greatest 

 width nearly half the length of the 

 culmen. 



d' . Bill with membranous expansion on 

 edge of maxilla near tip. 



-e' . Bill very short, narrow, rather pointed. 



a!' . Anterior edge of nostrils nearer the 

 base than tip. 



b" . Anterior edge of nostrils nearer the 

 tip than the base. 



c" . Bill, height at base two-thirds length 

 of culmen. 



a'" . Central tail feathers elongated. 



b'" . Central tail feathers not elon- 

 gated. 



«♦. Bill shorter than tarsus. 



b^. Bill longer than tarsus. 



/' Bill tumid or gibbous. 



g'. Bill with two-thirds of the culmen cov- 

 ered with feathers; pad-like feathering 

 around the eyes. 



h . Bill with naked parallel frontal proc- 

 esses. Feathering around eyes normal. 



CANVAS BACK. 



Arisionetta. 



jEthyia. 



SCAUP DUCKS. 



Fuligula. 



LABRADOR 

 DUCK. 



Camptolamus. 



GOLDEN EYE 

 DUCKS. 



Clangula. 



BUFFEL HEAD 

 DUCK. 



Charitoneita. 



LONG-TAILED 

 DUCK. 



Havelda, 



HARLEQUIN 

 DUCK. 



Histrionicus. 



STELLEr's DUCK. 



Heniconetta. 



SURF DUCKS. 



CEdemia. 

 Fischer's eider 



DUCK. 



Arctonetta. 



EIDER DUCKS. 



Somateria,, 



