March, 1920] 



The Canadian Field-Natukalist 



43 



regularly occuring in Canada. Comparable scoters 



are solidly coloured dark brown without variegation 



except for gradual hghtenings of face, fore parts, and 



below, — they are entirely without bars or streaks. 



King Eider, Somaieria spcctabilis. 



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, Sotualcria riiollissima borealis 

 can be shown to exist. The American Eider there- 

 fore becomes Somateria moUissima 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, Somaleria v. nigra. 



Plate III, Figs. 2, 2a. 



The Pacific Eider can usually be told from the 



Atlantic Eider by the black V-mark on the throat 



similar to that of the King Eider. In occasional 



MALE 



FRONT VIEW 

 Of BILL 



FEMF-'L.K 



EIDERS -GENE,RA\lgo^^gfe]g 



LES ELDERS -G CD PCS j| Arctonetta 



t 



HI 



lb 



Polyaticia 

 ateller'i 



^ 2.a 



sSorTiateria 

 V-nigra 



Arctonetta c/^o^a/jo/v 

 J^i5cheri 



cheek feathering projects forward of that of the 

 crown. 



Atlantic Eider, Somaleria moUissima. 

 Plate II, Figs. 1, 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, Somateria 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.ll 

 only be birds from a limited section of the Arctics 

 or occasional stragglers that need ever be confused. 



Spectacled Eider, Arcioneita fi^cheri. 

 Plate III. Figs. 3, 3a. 

 7 he 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- 



