CCIV 
APPENDIX. 
There appears a considerable variation in the size of individuals, in all the 
larger species of gulls. 
17. Larus Argentatus. Silvery Gull. 
Greenl. Birds, no. 20 . Temm. 764 . 
In the Memoir on the Birds of Greenland, the species described under this 
name was identified on the authority of Mr. Temminck with the common her- 
ring gull of our coasts ; the absence of the black markings of the primary quill 
feathers, which alone constitutes the distinction between them, being consi- 
dered by that eminent naturalist as a variation of plumage occasioned by 
climate : thus the Larus Argentatus was made to comprise two varieties, one 
peculiar to the Greenland seas, having the quill feathers a very faint 
ash-colour, with the ends and under parts white, without the admixture of 
black ; and the other the common herring gull. The present Expedition 
has furnished an instance which may be considered to confirm Mr. Tem- 
minck’s decision ; amongst a number of. the Greenland variety which had 
their nests on a cliff on one of the North Georgian Islands, one individual 
was observed to have black markings on the wings, and was fortunately, se- 
cured : on comparing this specimen with birds which have been killed on 
our own coasts, the black, markings of the quill feathers are found to corre- 
spond precisely in shape and situation ; the only perceptible difference being 
A 
that the, dark colour is not quite so deep in shade in the ''Polar as in the' 
European specimens, 
18. Larus Eburneus. Ivory GulL 
Greenl. Birds, no. 21 . Temm. 769 . 
A fine specimen of a bird of the first year Was killed in Davis’ Strait oh the 
14th of September, having all the immature markings of ’ the ' individual 
described i by Temminck as shot in Switzerland in March, with^ the ad- 
dition of numerous spots on (the shoulders* and sptiridus wings; this species 
