OF THE BEITISH ISLANDS. 429 



Genus HENICONETTA, or Rufous= breasted Eiders. 



Type, HENICONETTA STELLEEI. 



Heniconetta, of Gray (1840)*. By many authorities Steller's Eider, the 

 sole member of the present genus, is associated with the typical Eiders, but the 

 species possesses several characters which perfectly justify its removal from 

 Somateria. Steller's Eider belongs to that division in which the primaries are 

 uniform in colour. The bill is very peculiar. The edges of the upper mandible 

 are bent inwardly ; the lower mandible has the apical portion almost spatulated. 

 "Especially characteristic," writes Stejneger, "are the soft lobes formed by the 

 tomia of the upper mandible in the anterior half. When dried they roll up so 

 as to enclose the lower mandible, and become hard, the lateral outline thereby 

 being considerably changed, becoming unduly narrowed towards the tip." Both 

 sexes exhibit a metallic alar speculum ; the tertials are more or less falcate, and 

 on the head of the males are patches of stiff feathers. 



This genus contains but a single species, a rare abnormal migrant to the 

 British Islands, the distribution, habits, and characteristics of which will be 

 fully described in the following chapter. 



* Spelt Eniconetla. 



