208 LARID^. 



marked with yellowish brown. The remainder vary from pale 

 greenish grey to olive-brown and deep buft'. The markings, which 

 are yellowish brown or blackish brown, with some underlying jmle 

 purple, consist of spots and blotches disposed over the shell in an 

 infinite number of patterns. Numerous specimens measure from 

 1-9 to 2-2 in length, and from 1-37 to 1-5 in breadth. 



2. Buenos Ay res {E. W. W.). Saunders Coll. 



37. Argentine Republic, Oct. to Dec. A. H. Holland, Esq. [C.]. 



Larus glaucodes, Meyen. 



(Plate XVI. fig. 2.) 



Gavia roseiventris, Gould, P. Z. S. 1859, p. 97. 



Larus roseiventris, Abbott, Ibis, 1861, p. 166. 



Larus glaucodes, Saunders, Zool. ' Challenger ' Exped. ii. pt. viii. p. 138 



(1880) ; id. Cat. Birds B. M. xs.y. p. 203 (1896) ; Sharpe, Hand-l. 



i. p. 140 (1899). 

 Larus, sp. inc., 8cl. Zool. ' Challenger'' Exped. ii. pt. viii. p. 151 (1880). 



The eggs of the Pink-bellied Gull are as varied as the eggs of 

 L. macxdifemiis, and present the same types of coloration. They 

 measure from 1*95 to 2"3 in length, and from 1'4 to 1*53 in breadth. 

 There can be little doubt but that the two eggs collected by the 

 ' Challenger ' Expedition and marked " Tern Gull " belong to this 

 species. 



4. Falkland Islands (C. C. ^66o«). Gould Coll. 



2. Falkland Islands (C. C. ^.). Salvin-Godman Coll. 



2. Falkland Islands {Br. Deane). Saunders Coll. 



2. Falkland Islands. Voy. H.M.S. ' Challenger.' 



Larus ridibundus, Linn. 



Larus ridibundus, Thien. Fortpjlanz. ges. Viig. tab. Ixxxvii. fig. 2, a-k 



(1845 54) ; Hewitson, Eggs of Brit. Birds, ii. p. 491, pi. cxxxvi. 



figs, ii, iii (1856) ; Secbohm, Brit. Birds, iii. p. 310, pi. 53 (1885) ; 



Dresser, Birds Eur. viii. p. 357 (1878); Seebohm, Eqgs of Brit. 



Birds, p. 108, pi. 34. figs. 1, 2 (1896) ; Saunders, Cat. Birds B. M. 



XXV. p. 207 (1896); Sharpe, Hand-l. i. p. 140 (1899). 

 Gavia ridibunda, Baedeker, Eier Eur. Vog. tab. 72. fig. 3 (1855-63). 



The eggs of the Black-headed Gull are subject to great variation 

 both in shape and colour. The majority of the eggs are of a 

 pointed oval form. In colour they are greenish grey, olive-buff or 

 dark olive-brown, marked in every conceivable manner with brown 

 and blackish brown of many shades, and underlying pale purple. 

 A few s])ccimens are plain blue. They measure from 1-85 to 2-45 

 in length, and from 1-25 to 1-65 in breadth. 



75. Loch Ashie, Inverness, 3rd June Seebohm Coll. 



{E. Hargitt). 



4. Doime Lodge, Stirlingshire {E. Ear- Seebohm Coll. 



gitt). 



4. England {Hargitt Coll.). Seebohm Coll. 



2. Walney Island, Lancashire. Saunders Coll. 



