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



Gulls are involved, there appears no doubt of the application of 

 all the above references to the species now under description. The 

 L. slaiiciis of Temminck is not quoted, because, as will be here- 

 after shown, it is a different species. 



None but mature birds in the perfect summer state were killed 

 during the voyage, but these were very common throughout Da- 

 vis's Straits and Baffin's Bay. I am fortunately able to make the 

 history of its plumage complete from specimens in my brother's 

 collection of British birds ; and I am happy thus incidentally to 

 record it for the first time as an addition to British ornithology. 



In immature plumage it is mottled throughout with an uniform 

 light-brown and white, being distinguished from the young of 

 other well-described species by being without the darker marks 

 on the wings and tail : during the first year the bill has the upper 

 mandible less arched, the angular projection of the lower mandi- 

 ble not so defined, and the extremities of both lead-coloured. In 

 Avinter the mature bird has the head and neck mottled with brown, 

 as is usual with all the white-headed Gulls. In the perfect sum- 

 mer state, the whole plumage is white excepting the back, scapu- 

 lars, and wing-coverts, which are a very light ash-colour; the pri- 

 mary quill-feathers are still lighter, the ends and under part being 

 pure white ; there is no black whatsoever on any part of the plu- 

 mage: hence the bird from Hudson's Bay, described in Latham's 

 Synopsis at the page referred to above, with six of the primary 

 quill-feathers black at the ends, must have been another species. 



When arrived at maturity the bill is three inches in length, of 

 a lightish horn-colour, the angular projection of the lower man- 

 dible being bright red; orbits naked, straw-coloured and very 

 fierce ; legs and feet a livid flesh-colour. In size it is somewhat 

 inferior to the L. marinus; the bill, tarsus, and body of the latter 

 being decidedly greater. Length of a male specimen twenty-nine 



inches 



