4^ LtOYU's NATURAL HISTORY. 



yet to be discovered, and north of Wrangel Island, will one 

 day yield a glorious harvest of the eggs of this splendid species? 

 It is difficult to form any idea of what becomes of the thousands 

 which pass Point Barrow to the north-east in the autumn. It 

 is certain that they do not return along the shore as they went. 

 Nevertheless, at that season of the year, they must of necessity 

 soon seek lower latitudes. Perhaps the most plausible sup- 

 position is that, soon after leaving Point Barrow, perhaps when 

 they encounter the first ice-pack, they turn and retrace their 

 steps so far out to sea as to be unnoticed from the land, and 

 pass the winter on the edge of the ice-field, proceeding north 

 to their breeding-ground as the pack travels north in the spring." 



Nest. — As yet undescribed. 



Eg-gs. — The British Museum contains an egg ascribed to this 

 species, from Christianshaab, on the south shore of Disco Bay, 

 in Greenland. The old bird is said to have been shot on the 

 nest, and its skin sent home with the egg, according to Mr. 

 Seebohm, to whose collection it formerly belonged. It is figured 

 in his " Coloured Illustrations of the Eggs of British Birds " 

 (plate 36, fig 6). The egg of the Wedged-tailed Gull seems 

 to be very similar in colour and in character to that of Sabine's 

 Gull, but is a little larger. i\xis, 1-9 inch; diam. 1*3. 



THE TRUE GULLS. GENUS LARUS. 



Larus, Linn. Syst. Nat. i. p. 224 (1766). 



(Type not indicated.) 



In all the remaining Gulls the tail is nearly, or quite 

 square, and in this section of the sub-family Larince, Mr. 

 Saunders places five genera, characterised principally by the 

 size of the hind-toe and its web. Thus the genera Larus and 

 Gaaia?ius (the latter containing only one species, G. pacificiis 

 from the southern ocean) have the hind-toe free, and mode- 

 rately or well-developed. 



The genus LeucophcEus contains only a single species, 

 L. scoresbyii, from the extreme south of South America, and 

 has the feet coarse and the webs considerably indented, while 

 the hind-toe is joined to the inner toe by a rugose membrane. 



In the genus Pagophila, which contains only the Ivory Gull, 



