M 



arch, 



1920] 



The Canadian Field-Natukalist 



43 



regularly occunng in Canada. Comparable scotcis 

 are solidlj' coloured dark brown without variegation 

 except for gradual hghtenings of fcice, fore parts, and 

 belcw, they are entirely without bars or streaks. 



King Eider, Somaieria spedabilis. 

 Plate II, Figs. 3. 3a. 



The greatly enlarged bill process, coloured bright 

 yellow, easily distinguishes the male of this species. 

 The feathering of the fore crown and the cheeks 

 are diagnostic in other plumages. In this species 

 the crown feathers extend down the ridge of the 

 bill as far as the rear of the nostrils, whilst the 

 feathering of the cheeks does not extend as far as 

 that of the crown. In other comparable eiders the 



the Northern Eider, Somaieria mollissima borealis 

 can be shown to exist. The American Eider there- 

 fore becomes Somaieria mollissima dresseri. These 

 two American forms can only be separated by the 

 bill processes on the sides of the crown. In the 

 American Eider these processes in either sex are 

 broad and end in a well rounded instead cf a 

 pointed tip as in the Northern and the Pacific 

 Eiders. 



Pacific Eider, Somaieria v. nigra. 



Plate III, Figs. 2, 2a. 



The Pacific Eider can usually be told from the 



Atlantic Elder by the black V-mark on the throat 



similar to that of the King Eider. In occasional 



MALE 



KROM'l' VIEW 

 Of BILL 



FEMALli 

 FliA^FA,LK. 



EIDERS 



LES EIDERS 



GENE-RA ] 



-Genres J 



Polyaticta 

 Sornateria 

 Arct on eit a 



u: 



--' sea 



7941 



Polyosticta 

 stelleri 



xSomater^ia 

 V-nigra 



Arct one! t a c-^-^^^'^^o/v 

 [isScherl 



cheek feathering projects forward of that of the 

 crown. 



Atlantic Eider, Somaieria mollissima. 



Plate II, Figs. I, la. 2, 2a. 



The long Y-shaped arms of the bill processes ex- 

 tending up the sides of the crown are distinctive of 

 the male Atlantic and the Pacific Eiders. In the 

 females of these species the crown feathering not 

 nearly reaching to the nostrils and the cheek feathers 

 extending beyond those of the crown are diagnostic. 



In the 1910 A.O.U. Check List, the standard au- 

 thority, the American Eider is given as a full 

 species, Somaieria dresseri. Late investigation, how- 

 ever, has shown that it is only a subspecies of the 

 eider common to the New and Old Worlds (At- 

 lantic Eider), as all intermediates between it and 



Atlantic specimens this throat mark is said to be 

 present, in which case and in females, the relatively 

 larger and heavier bill, the shorter and more acutely 

 pointed bill processes on the fore crown, and the 

 slightly blunter ending of the feathering on the 

 sides of the bill of the Pacific seem to be the only 

 diagnostic guides. None of these points are satis- 

 factorily obvious or reliable but the ranges of the 

 two species are so widely separated that it w:l! 

 only be birds from a limited section of the Arctics 

 or occasional stragglers that need ever be confused. 



Spectacled Eider, Ardonetia fischeri. 

 Plate III, Figs. 3, 3a. 

 The white spot about the eye and the black spec- 

 tacle mark of the male Spectacled Eider is unmis- 

 takable. In the female this white eye spot is indi- 



