224 WATER FOWL. 



Adult Male. In color of plumage and its general distribu- 

 tion there is no appreciable, certainly no specific difference, 

 between the male of this species and the Common Eider of 

 Greenland and the northern regions of the Old World, and the 

 description given of the succeeding species may answer very 

 well for the American Eider. But the two forms, apart from 

 their plumage, can be readily distinguished by the shape of the 

 frontal angles, or the naked portion running from the base of the 

 bill onto each side of the forehead. In S. mollissima, the next 

 species, these angles are narrow and more or less pointed and 

 smooth, while in the American Eider they are broad and rounded 

 at the end, and much corrugated. In general measurements 

 there is very little difference between the two species. The bill 

 of the present one, from tip to end of frontal angle, averages 

 about 2^y inches; greatest width of angle, .45; culmen, i^. 



In some male specimens a dusky V-shaped mark is observable 

 on the throat, but this is rare. 



Adult Female. With the exception of the shape of the frontal 

 angle, the female of this species is not to be distinguished from 

 that of the Common Eider. 



Downy Young. Like that of the Common Eider. 



