Mr. R. B. Sharpe on the American Eider Duck. 51 



f*Pleurotoma Bertrandi, Pajr. Ranges from South France 

 to the Morea. 



— l<Bvigata, Phil. This is the typical form, which is 

 not found living north of the Channel Islands. It is a 

 rare fossil. 



— rufa, Mont, (moderately common). 

 -, var. semicostatttj Jeffr. Hob. Channel Islands. 



*. 



turricula^ Mont. 



Cyprcea europcea, Mont. 



Utricidus truncatulus, Brug. 



obtusus, Mont. 



* Lajonkairiana, Bast. 



'^ Bulla hydatisj L. (fragments only). 

 * Conovulus bidentatus, Mont. 



Rhizopoda. 



Cornuspira foliaceus^ Phil. 

 Biloculina, sp. 



ECHINODERMATA. 



Ecliinocyam.us pusillus. 

 Spatangus purpureus. 



VI. — On the American Eider Buck. By R. B. Sharpe, 

 F.L.S. &c., Librarian to the Zoological Society of London, 



Some time ago I received a hint from Mr. D. G. Elliot, so well 

 known for his great work on the Birds of North America, 

 that the Eider Duck of Europe was not identical with the 

 Eider of America, although both species had, from the time 

 of Linnaeus, been united under the name of Somateria mollis- 

 sima. Mr. J. H. Gurney also wrote to me independently on 

 the same subject; and having had occasion to examine the 

 matter when writing the history of the Eider Duck for the 

 * Birds of Europe,' I find that the surmise of both Mr. Elliot 

 and Mr. Gurney is correct, and that the American Somateria 

 is not the same as the European species. To begin with, 

 the American Eider Duck is a very much finer bird than its 

 European congener, and both male and female have the 

 sickle-shaped inner secondaries more fully developed. The 

 chief difference, however, lies in the bill, the form of which in 

 each species is illustrated by the accompanying woodcuts. 



From these it will be seen that in Somateria Dresseri^ as I 

 propose to name the American bird, the bare ridges rimning 

 up from the nostril to the eye are very much broader, and 

 also differ in being distinctly rugose. Again, the sea-green 



