386 NATATORES. 



dusky in the centre, on the angle of the lower mandible. 

 Back and wing coverts slate grey ; quills black barred with 

 white and with white tips ; all the rest of the mature birds 

 white. The young are mottled with brown and white till 

 the autumn of the third year. 



THE BURGOMASTER GULL (LaTUS gla 



This species is nearly as long as the former, but six or 

 seven inches less in the extent of the wings. It inhabits 

 more northerly, or rather more exclusively northerly, than 

 the former, visits only the more northerly parts of this 

 country in the winter, and is rarely seen even there. It is 

 understood to breed only in the north, the very extreme of 

 which, as far as the water is at all open, it reaches in the 

 summer. It is said to inculcate on rocks. 



Bill brownish yellow, with the spot on the under man- 

 dible bright red ; irides yellow, orbits reddish, feet livid ; 

 back, shoulders, and wing coverts, light bluish ash ; rest 

 of the plumage white. The young mottled with brown and 

 white. 



THE ICELAND GULL (LaTUS 



This, like the former, is only a winter visitant in the nor- 

 thern isles. It is a smaller and less powerful species, but 

 more handsome in its form than the former, and proportion- 

 ally better winged, the closed wings extending beyond the 

 tail ; and, in accordance with these differences of form, it is 

 a more active bird. Colours nearly the same as in the last 

 species, only the ash colour on the upper part a little paler 

 and clearer in the tint ; the bill half an inch shorter, and 

 considerably more slender, The brown in the mottled plu- 

 mage of the young birds is also paler. It inhabits far to the 

 northward in the summer, and is presumed to nestle on the 

 polar rocks, where numbers have been seen congregating, as 



