344 Capt. SaBINE's Memoir on the Birds of Greenland, &c. 
Gulls are involved, there appears no doubt of the a pplication of 
all the above references to the species now under descri ption. The 
L. glaucus 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 
winter 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 jt 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 
