516 GULL DRIBE. 
species, the glaucous gull (Z.glawcws), in which the males may measure fully 32 inches, 
is readily distinguished by the adult summer-plumage being nearly white through- 
out, as well as by the comparative shortness of the wings and feet. Essentially an 
Old World Arctie bird, this gull only wanders in winter to temperate and tropical 
Europe; while in the North Pacific it is represented by the allied L. glaucescens, 
ranging from America to Kamschatka, and distinguished by the faint grey 
mottlings on the wings. Another occasional wanderer to the British Isles from 
the north is the Iceland gull (Z. lewcopterus), which may be distinguished from the 
last by its length not exceeding 22 inches, and likewise by the proportionately 
much longer wings and legs. Bonaparte’s gull (L. philadelphia), a small species 
with a greyish black head and upper neck, is remarkable for its habit of breeding 
in tall trees. 
Represented only by the common cireumpolar kittiwake (/issa 
Kittiwakes. 
a brs tridactyla) and an allied North Pacific species (2. brevirostris) from 

KITTIWAKES NESTING. 
the region lying between Alaska and Kamschatka, these gulls are distinguished by 
the shortness of the metatarsus and the absence or rudimentary condition of the 
first or hind-toe. It is not a little curious that while in most districts examples of 
the common kittiwake in which the latter toe persists are but rarely met with, in 
