262 LAKID^. 



Genus PAGOPHILA Kemp, Natiirl. Syst. 1829, p. 69. 

 Type : P. eburnea (Phipps). 



PagdpJiila, from trayos=ioe, and ^cX6m = I love. 



Pagophila eburnea. Ivory Gull. 



Larus eburneus Pldpps, Voyage towards the North Pole, 

 1774, p. 187 : Spitsbergen. 



Pagophila eburnea {PUpps) ■ B. O. IT. List, 1st ed. 1883, p. 186; 

 Saunders, Cat. Birds B. M. xxv. 1896, p. 301 ; id. Manual, 

 2n(l ed. 1899, p. 685. 



Ebumeus=oi ivory. 



Distribution in the British Islands. — An Occasional Visitor 

 during the colder months o£ the year, and sometimes met with 

 in summer. Tl, is more numerous in the northern parts of 

 Great Britain, but has been noticed in many counties as far 

 south as Cornwall, while three have been recorded in Ireliind. 



General IXntrihittion. — The Ivory Gull is a circumpolar 

 species, breeding in the Arctic regions up to about 81° N. 

 latitude. In winter it wanders southwards and has been 

 recorded in the north o£ France, Switzerland, Long Island, 

 U.S.A., Lake Ontario, and British Columbia. 



Genus RISSA Stephens, Gen. Zool. xiii. pt. 1, 1826, p. 180. 

 Type : li. tridactj/Ia (Linn.). 



Sissa, probably latinized and softened from the Icelandic Ritsa (Briinnich, 

 Onntli. Boreal. 1764', p. 42). Derivation unknown. 



Rissa tridactyla. Kittiwake. 



Larus tridactylus Lhmwus, Syst. Nat. 1758, p. 136 : 

 Great Britain. 



Eissa tridactyla (Linn.) ; B. O. U. List, 1st ed. 1883, p. 187 ; 

 Saunders, Gat. Birds B. M. xxv. 1896, p. 305 ; id. Manual, 

 2nd ed. 1899, p. 683. 



Tridactyla=Tpi?.aKTv\o%, three-toed ; from rpeis, and ^aKriJXos. 



