HYDEOCHBLIDON.— GELOCHELIDON. 399 



plumis auricularibus nigris; praepectore lateral! plumbeo, plagam conspicuam formante; subalaribna 

 pallide cineraceis ; axillaribus et remigibus iutus plumbescentibus. Long, tota circa 9-5, alse 7-9. (Deser. 

 maris adulti ex Cay Dolores Cbannel. Mus. nostr.) 



Ilab. North Ameeica, from Alaska and the Fur Countries ; breeding from the Middle 

 United States, west of the Alleghanies, northward ^ to Hudson's Bay 3. — Mexico^, 

 Sinaloa (Streets ^^), Matamoros (Dresser^), Laguna Verde, Vera Cruz (Trujillo^), 

 Putla {Boucard % Laguna de San Baltazar, Laguna de Chapulco, State of Puebla 

 {Ferrari-Perez^), near the city of Mexico (White ^^), Mazatlan (Gra^san ^ ^ ^^), 

 Manzanillo (Xantus^^), Acapulco (Mrs. II. H. Smith % Gulf of Tehuantepec, San 

 Mateo (Sumichrast ^^ ^oj . British Honduras, Southern Water Cay ^^ ^^, Curlew 

 Cay, Cay Dolores Channel ^ (0. S. & F. I). G.); Guatemala, Coban (0. S.^ i"); 

 Honduras ^ ; Costa Eica, Punta Arenas (Zeledon ^) ; Panama (M'Leannan ^^ ^^). — 

 Guiana 8; Peru^; Chile s. 



The present species is the representative in America of the Black Tern (H. nigra) of 

 Europe, which it very closely resembles in its winter plumage, but is distinguished in 

 summer by the sooty-black under surface and by the more conspicuous line of white 

 along the carpal edge of the wing. 



H. surinamensis is a bird of somewhat irregular distribution in North America, 

 breeding in the north in the marshes of the Fur Countries, and in similar localities 

 throughout the interior of the United States. It is common in flocks in many places 

 in Central America, appearing at Mazatlan, according to Grayson, in September and 

 October, and remaining all the winter ^^. It has been more frequently observed on 

 the Pacific coast than on the Atlantic side or in the interior, and extends its range in 

 winter to Peru and Chile ^. 



The American Black Tern is a marsh-loving bird in the breeding-season, and feeds 

 more on insects than on fish, showing great activity in pursuit of the former. 



The nest is generally made of reeds placed on tussocks, and is often of large size. 

 The eggs resemble those of E. nigra, being of a pale buff colour or brownish-buff, 

 heavily blotched or spotted with reddish-brown or blackish-brown. 



GELOCHELIDON. 



Gelochelidon, Brehm, Vog. Deutschl. p. 774 (1831) ; Sauaders, Cat. Birds Brit. Mus. xxv. p. 25 

 (1896). 



This genus belongs to the section of Terns in which the outer tail-feathers are 

 pointed and longest. The tarsus is unusually lengthened, exceeding the dimensions of 

 the middle toe and claw, while the tail is less than half the length of the wing. The 

 bill is conspicuously stout and obtuse, whence the trivial English name of the " Gull- 

 billed " Tern is applied to the only species of the genus Gelochelidon. 



The single representative is found over the greater part of the temperate regions of 



