310 ITORY GULL. 



frequent, reaching southward to Spain and to Tre- 

 bisond. A bird under the same name is also intro- 

 duced in the Northern Zoology, which is said to 

 spread northward as far as Arctic America, breeding 

 there and retiring southward when the winter sets 

 in. 



In the summer or breeding state, the head, neck, 

 the rump and tail, and all the under surface of the 

 bird are pure white, the mantle x scapulars and wing- 

 -overs pearl grey, quills black with white tips ; the 

 bill is greyish green passing into yellow at the tip ; 

 eyelids vermilion red ; legs and feet greenish grey. 

 In winter, the head, sides of the neck and nape, 

 are streaked with brocoli-brown. 



The young have the upper plumage clove-brown, 

 the feathers margined with greyish white ; under- 

 neath they are clouded with a paler brown, the degree 

 varying with age ; quills blackish grey ; the basal 

 part of the tail white, with the other part black, 

 tipped with greyish white. 



In the two birds which follow, the form slightly 

 varies, in the first the feet are more tern-like, the 

 webs deeply cut ; while the second, a truly mari- 

 time bird, leads to the petrels. 



THE IVORY GULL, LARUS EBURNEUS. Larus 

 candidus, Flem. Mouette blanche ou sancteur, 

 Temm. Ivory Gull of British authors. It is to 

 Mr. Edmondstone also that we are indebted for the 

 first notice of the Ivory Gull as a British bird, the 



