geFjAt black-backed gull. 85 



black heads, with the beak of Larus and the dark head of Xema. 



My figure is from the English specimen in the late Mr. Koss's 

 collection, a drawing of which, with Mrs. E.oss's consent, has been 

 taken for this work by the Rev. F. Wright, of St. Stythray, Cornwall, 

 to both of whom my best thanks are tendered. 



The figure of the egg is from my own collection. It was taken by 

 Herr Glitsch in South Russia. 



