IVORY GULL. 



Gavia alba. 



Char. Entire plumage white ; bill yellow, shading to greenish gray at 

 the base ; legs and feet black. Length i8 inches. 



In immature birds the upper parts are more or less spotted with 

 brownish gray ; wings and tail tipped with dusky brown ; bill black. 



Nest. On a sea-beach or high cliff, — a slight depression in the soil, 

 sparsely lined with grass or moss, sometimes made of moss and sea-weed, 

 with a thin lining of down and feathers. 



Eggs. 1-2 ; pale to dark buff, more or less tinted with olive, some- 

 times olive drab, marked with several shades of brown and lilac ; aver- 

 age size about 2.40 X 1.70. 



This beautiful species, called sometimes the Snow Bird, from 

 the pure whiteness of its plumage, is found in great numbers 

 on the coasts of Spitzbergen, Greenland, Davis's Straits, on 

 Baffin's Bay, and on various parts of the northern shores of the 



