546 Capt. Sabine's Memoir on the Birds of Greenland, <^c. 



conjecture, may have been caused by sickness or by scanty supply 



of food. 



20. Larus Argentatus. Silvery Gull. 



The bird now under consideration does not appear to have 

 been described in any of the books which are referred to in this 

 memoir. It is necessary therefore to explain why the name of 

 argentatus or silvery, which has been used before, has been at- 

 tached to it. A Larus argentatus was introduced by Briinnich, 

 who was followed by Gnielin; but the bird to which the name 

 was applied is evidently the Larus fuscus or Herring Gull of La- 

 tham, in winter plumage : as is also the Silvery Gull of the ^rc^?c 

 Zoology and of Latham's Synopsis. In this opinion Temminck 

 concurs, as is shown by his quotations in his Manuel under the 

 head of Larus glaucus. Latham in the Index Ornithologicus takes 

 up the iMrus argentatus of Briinnich, but considers it erroneously 

 as an ag-ed bird of the Larus marinus or Great Black-backed Gull. 

 Montagu finding the term argentatus at liberty, applied it in his 

 Dictionary to his Less Black-backed Gull ; but it will be seen by 

 reference to the Manuel of Temminck that the Less Black-backed 

 Gull is the Larus fuscus of Linneus and Gmelin. 



I apprehend that the reason why the bird under consideration 

 has not been hitherto distinctly described is to be found in its 

 general resemblance to the Larus glaucus: it will be therefore 

 best distinguished by a comparative description. In the general 

 character of the plumage they are alike, differing from the other 

 large species of this genus in the entire absence of black in the 

 primary quill-feathers ; the shade of the ash-colour of the back, 

 scapulars, and coverts, varies in different specimens from almost 

 the lightest perceptible tint to a darker than the darkest Larus 

 glaucus that was killed on the voyage ; the principal distinction 



between 



