lAEcrs. 217 



Three eggs of Audouin's Gull in the Collection have a buff 

 ground and are pretty thickly spotted and blotched with blackish 

 brown. A fourth is of a kind of creamy-buff tint, and the mark- 

 ings, which are similar in character to those on the other examples, 

 are of a pale yellowish-brown colour. AU four have the usual 

 pale purple underlying markings. They measure respectively : 

 2-4 by 1-75; 2-45 by 1-73; 245 by 1-8 ; 2-53 by 1-66. 



] . Columbretes Island, Spain. Saunders Coll. 



1. Columbretes Island, lat May. Saunders Coll. 



1. Columbretes Island, April. Saunders Coll. 



1. Toro, Sardinia, 25th May (Lord Saunders Coll. 

 Lilford). 



Larus delawarensis, Ord. 



(Plate XVII. fig. 5.) 



Larus delawarensis, Baird, Brewer 8f Ridqw. Water Birds N. Am. ii. 

 p. 244 (1884) ; Saunders, Cat. Birds B. M. xxv. p. 273 (1896) ; 

 Sharpe, Hand-l. i. p. 142 (1899). 



The two eggs of the Eing-billed Gull in the Collection are of 

 quite dissimilar types. One is of a regular oval form and has an 

 olive-buff ground, sparingly marked, except at the larger end, where 

 there are huge confluent blotches forming an irregular zone, with 

 spots and specks of deep chocolate-brown ; the underlying pale 

 purple markings are few and inconspicuous. The second specimen 

 is a pointed oval and has a light buff ground, boldly marked all over 

 with spots and blotches of blackish brown. The underlying mark- 

 ings on this egg are numerous, large and conspicuous. The two 

 measure respectively : 2-25 by 1"63 ; 2-35 by 1'6. 



1. Little Slave Lake, Canada (S. Jones : Salvin-Godman Coll. 



Henshaw Coll.). 

 I. North America. Saunders Coll. 



Larus califomicus, Lawr. 



(Plate XVIII. fig. 2.) 



Larus califomicus, Baird, Brewer Sr Bidgw. Water Birds N. Am. ii. 



p 242 (1884); MncFarlane, Proc. U.S. Nat. Mus. xiv. p. 418 



(i891); Saunders, Cat. Birds B. M. xxv. p. 276 (1896); Sharpe, 

 a««rf-?. i. p. 142 (1899). 



The eggs of the California Gull in the Collection show con- 

 siderable variation, but can all be matched by those of L. fuscus, 

 and a larger series would, no doubt, display all the types to be found 

 among the eggs of that species. They measure from 2-45 to 2-75 

 in length, and from 1-75 to 1-85 in breadth. 



1. North America {Smiths. Inst.). Salvin-Godman Coll. 



1. North America \T. M. Brewei-). Saunders Coll. 



1. North America, 16th May Samiders Coll. 



(R. Bidgway). 



1. Anderson Kiver, Arctic America, Saunders Coll. 



6th July (iJ. MacFarlane). 



