534 LARID^. 



nuptial plumage. On the Pacific side Mr. Salvin obtained 

 it in Guatemala. 



The Gull-billed Tern breeds in colonies on islands or sand- 

 banks in lagoons, and the nests are merely slight hollows with 

 at times a few bits of seaweed or dry grass for a lining. 

 Mr. Seebohm, who has visited large colonies at Missolonghi 

 and at Smyrna, says that two is the usual number of eggs ; 

 frequently three, but never four. Their ground-colour is of 

 a greyish-white or yellow-ochre, occasionally of a pale greenish 

 tint which soon fades, blotched and spotted with different 

 shades of brown ; average measurements are 2 by 1'4 in. 

 During the breeding-season its note resembles the syllables 

 clie-ah, and at other times it utters a laughing af, af, af, 

 like a Gull. The food of this species is somewhat varied ; 

 in Ceylon, Col. W. V. Legge found it to consist of frogs, 

 crabs, and fish ; in Egypt, Yon Heuglin observed the bird 

 darting into the dense smoke of a prairie fire in pursuit of 

 locusts ; and in Algeria Mr. Salvin noticed it hovering over 

 grass-fields and pouncing upon grasshoppers and beetles ; it 

 also captures many species of insects on the wing. Its 

 flight is graceful but not very rapid, its long wings being 

 plied with measured steady strokes. In its partiality for 

 lagoons, tidal rivers, and inland lakes of fresh or brackish 

 water, and in its comparatively short, although distinctly 

 forked tail, and moderately-webbed feet, this species forms 

 a natural link between the Marsh Terns and those which 

 frequent the sea-coast. It was made the type and sole 

 representative of the genus Gelochelidon, by Brehm, who, 

 very consistently, erected the genus Sylochelidon for the 

 Caspian Tern. 



In the adult in summer the bill is black, and averages one 

 inch and a quarter in length from the point to the feathers 

 on the forehead ; the angle at the symphisis of the lower 

 mandible rather prominent, whence the name Gull-billed ; 

 irides reddish-brown ; forehead, crown, and nape jet black ; 

 neck behind greyish-white ; back, scapulars, wings, the 

 coverts, secondaries, and tertials, upper tail-coverts, and 

 central tail-feathers uniform pale ash-grey ; outer tail-feathers 



