394 APPENDIX. 



Genus XEMA. Type by monotypy : A', salinii (Sabine). 



Genus PAGOPHILA. Type by monotypy : P. eburnea 

 (Phipps). 



Pagophila eburnea. In the A. 0. U. Check-List the Ivory 

 Gull is named P. alba. The description given by 

 Gunnerus of his Laws albus (in Leem's Beskr. Finin. 

 Lapp. 1767, p. 285) appears to be too indefinite to 

 warrant the use of the name. 



Genus BISSA. Type by monotypy : R. tridactyla (Linn.). 



Genus STERNA. Type by Linnean tautonymy : S. hirundo 

 Linn. 



Sterna hirundo. This species has usually been called Sterna 

 fluviatilis Naum. Prof. Einar Lonnberg (Ibis, 1913, 

 p. 301) has gone carefully into the question whether 

 S. hirundo Linn, should be applied to the Common or 

 to the Arctic Tern. He has given good reasons for 

 referring it to the former species, and the Committee 

 have accepted his decision. 



Sterna paradisea. Briinnich's name, published in 1764, has 

 many years' priority over S. macrura Naumann, pub- 

 lished in 1819. 



Sterna caspia. Hartert in the Hand-list of British Birds 

 uses Lepechin's name, S. tscliegrava, for this bird ; 

 Lepechin, however, was not a consistent binomialist, 

 and the Committee cannot adopt his names. His 

 description, published in the same work, antedates that 

 of Pallas by a few pages only. 



Sterna anglica. For the Gull-billed Tern, Hartert in the 

 Hand-list of British Birds adopted Gmelin's name, 

 S. nilotica, based on a bird described by Hasselquist 

 from Egypt. Gmelin's description, however, is inade- 

 quate and misleading ; also he described the feet as 

 "incarnati/ 7 whereas they are black with a reddish tinge. 



