87 



Order XV.— PALMIPEDES. fTemminch.J 



Family LARID^. (Bonaparte.) 



Genus Sterna. (Linn(Bus.) 



Generic Characters. — Bill as loug or longer than the head, 

 nearly straight, compressed, tapering, edges sharp, pointed, 

 mandibles of equal length, the upper one slightly curved 

 towards the point; nostrils near the middle of the beak, slit 

 longitudinally, and pierced from side to side. Legs small, 

 naked above the knee for a short distance; tarsi very short; 

 four ' toes, the three anterior united by membranes, deeply 

 concave in front; hind toe free; middle claw longer and sharper 

 than the others. "Wings very long, pointed, the first quill 

 feather the longest. 



ALLIED TERN. 



Sterna affinis. 



Sterna affinis, Temminck. Euppell. 



" media, Hossfield; Lin. Trans., 



vol. xiii, p. 199. 



" arabica, Eheenbeeg. 



Tkalasseus affinis, Bonapaete. 



Hirondelle de mer voyageuse. Of the Feench. 



RiippelVs Seeschioalhe, Of the Geemans. 



Specific Characters. — Middle toe with claw longer than the 

 tarsus; beak long, yellow; feet black; wings pass the end of the 

 forked tail by an inch and a half or more. Length fifteen inches ; 



