GELOCHELIDON. 177 



The eggs of the Great-billed Tern resemble many of those of the 

 Gull-billed Tern. They are of a broad oval or elliptical shape. 

 The ground is of a yellowish-buff colour, and it is marked, pretty 

 evenly all over, with spots and small blotches of yellowish brown 

 and pale purple. On some specimens the markings consist of short 

 thick lines and scrawls. The eleven examples measure from 1'73 

 to 1*97 in length, and from 1-35 to 1*41 in breadth. 



11. Ucayali River, E. Peru, 10th Sept. Saunders Coll. 

 (E. Bartlett). 



Genus GELOCHELIDON, Brehm. 

 Gelochelidon anglica {Mont.). 



Sterna anglica, Thien. Fortpfianz. ges. Viig. tab. Isxxii. fig. 7, a-i (1843- 

 54); Saunders, Ibis, 1871, p. 398; Dresser, Birds Eur. viii. p. 295 

 (1877) ; Baird, Brewer Sf Ridgw. Water Birds N. Am. ii. p. 277 

 (1884) ; Seebohm, Brit. Birds, iii. p. 263, pi. 47 (1885) ; North, Nests 

 ^- Eggs Austr. Birds, p. 355, pi. svii. fig. 2 (1889) ; Oates ed. Hume, 

 Nests S,- Eggs Lid. B. iii. p. 304 (1890) ; Sharpe, Ibis, 1891, p. 116; 

 Holland, Ibis, 1892, p. 212 ; Seebohm, Eggs of Brit. Birds, p. 99, 

 pi. 31. tigs. 6, 8(1896). 



Gelochefidon anglica, Baedeker, Eier Eur. Vog. tab. 24. fig. 3 (1855-63) ; 

 Salvin, Ibis, 1859, p. 364 ; Saunders, Cat. Birds B. M. xxv. p. 25 

 (1896) ; Sharpe, Hand-l. i. p. 134 (1899). 



The eggs of the Gall-billed Tern are broad ovals, sometimes 

 slightly pointed at the small end. The ground varies from a grey- 

 ish or huffish white to a pale buff, stone-colour or brown. The 

 markings are of small size and are, as a rule, evenly distributed 

 over the shell. They consist of spots and blotches of dark brown or 

 olive-brown and very prominent underlying grey. 



The above description applies to eggs from the Old World and 

 N. America. Those taken in South America are more varied, the 

 ground being frequently tinged with pale yellow, pale green or 

 pale blue, and the markings being much larger and consisting, very 

 often, of coarse blotches and streaks. They vary from 1*8 to 2*2 

 in length, and from 1"3 to 1"57 in breadth. 



