616 LARIDiE. 



of Europe down to the Mediterranean, the Black Sea, and the 

 Caspian ; and it also visits the shores and lakes of North 

 Africa and Asia Minor. In Siberia a large race with a 

 somewhat darker mantle is found, which has been distin- 

 guished by several different specific names, but the Editor 

 is unable to . admit its validity. It would appear that the 

 greatest development is attained in the north and east ; 

 but in Japanese and Chinese waters all sizes are found ; 

 and the colour of the mantle, which is very variable, 

 becomes lightest in western individuals, accompanied by 

 a corresponding deterioration in size. On the American 

 side of the Pacific, from the coast to Great Bear Lake, it is 

 replaced by a closely-allied, but separable and smaller species, 

 which goes by the name of Lams hrachyrhynclms, Richard- 

 son, This, in its turn, gives place throughout the rest of 

 North America to Lams delawarensis, Ord, a species rather 

 larger than L. canus, with a lighter mantle, and a stouter 

 bill transversely double-zoned. An immature example of 

 our Common Gull was, however, obtained at Henley Harbour, 

 Labrador, on the 21st of August, 1860 (P. Z. S. 1878, 

 p. 178) ; but with that exception this species has not been 

 known to occur in North America, nor even on the islands 

 of the Atlantic. 



In the fully adult bird in summer the bill is greenish- 

 yellow at the base, rich yellow towards the point, irides 

 golden-brown, edges of the eyelids red ; the whole head and 

 neck pure white ; the back and all the wing-coverts pearl- 

 grey, secondaries and tertials the same, but broadly edged 

 and tipped with white ; primaries black on the outer web, 

 with a small portion of pearl-grey at the base of the inner 

 web, the proportion of grey increasing on each primary in 

 succession ; the first and second primary with a patch of 

 white on both webs near the end, but the tips of both are 

 mainly black ; the third, fourth, fifth, and sixth have white 

 tips, followed by a broad black bar, surmounted by a patch 

 of white blending into grey. Tail-coverts and tail-feathers 

 pure white ; chin, neck in front, breast, and all the under 

 surface of the body and tail pure white ; legs and feet 



