286 THE NESTS AND EGGS OF 



Kittivvakes and Glaucous Gulls. The nests found by Dr. 

 Malmgren on the cliffs of Spitzbergen are described as 

 shallow hollows in the soil on the ledges, lined with 

 dry grass, moss, weeds, and a few feathers. Those found 

 by M'Clintock on the Parry Island group were made 

 upon the ground entirely of moss, but one of them 

 contained a few feathers and a little white down. 



Range of egg colouration and measurement : 

 The eggs of the Ivory Gull are never more than two in 

 number, and very frequently appear only to be one. 

 They vary in ground colour from olive-brown to bufifish- 

 brown, spotted with dark brown and pale brown, and 

 with underlying markings of lilac-gray. In the distri- 

 bution of the markings two types occur, one in which 

 they are pretty evenly distributed over the entire surface 

 of the ^%%-, and the other in which they are mostly on 

 the major half, where they sometimes form an irregular 

 zone. Average measurement, 2*5 inches in length, by 17 

 inch in breadth. The duration of the period of incu- 

 bation is unknown, as is also which sex performs the 

 duty. Professor CoUett has described a fine series of the 

 eggs of this Gull in the Ibis (1888, p. 440). 



Diagnostic characters : The eggs of this Gull 

 somewhat closely resemble those of the Common Gull in 

 colour, but are larger in size. The locality of the eggs 

 should be sufficient to determine their identity, as the 

 Common Gull does not breed within the same area. 

 The eggs of the Kittiwake are also much smaller. 



