S8 BIRDS OF BRITISH GUIANA. 



Bartica, Abarv River (MrConnell collection) ; Ruptinuni River, 

 Ourunei (JT/titflt/) ; Waini River (Beehe) ; Geororetown (Quelch). 



Extralimital Range. Yeueznela, Brazil, Ecuador, Peru, Bolivia, 

 Paraguay, Argentina. 



Hal'its. Scbomburgk says (Reis. Giiiaii. iii. p. 761) that tliis 

 species is not only f'uuiiJ on the coast but occurs up the inland 

 rivers and along the tributaries to the sand dunes. It lays two, 

 or at the most, three eggs in a hollow in the sand-banks. It 

 occurs also on the Rupunnni River. 



^Ir. Beebe, who observed this bird on the Abary Savannas (Our 

 Search tor a AVildernes>, p. 378], writes : — '"Terns were one of the 

 most p)icturesque features of the savanna, flying over and around 

 the island in small flocks, the large Great-billed fellows with black 

 caps and wings, beat Vjack and forth, or hung fluttering over 

 the lagoon, and now and then dropped plummet-like after a 

 small fish." 



Genus GILOCHELIDON Brehm. 



Geloehelidon Bi-ehm, Vog. Deutsclil. p. 774. 1S31. Ty^x- G. uilotica 

 (Gmel.). 



The bird on which this monotypic genus Avas founded is some- 

 what more stoutly built than Terns generally, with the outer 

 tail-feathers pointed and longest, the V)ill short and stout, the legs 

 long, and the tarsus longer than the bill. 



54. Geloclielidon nilotica gronvoldi. 

 Gull-billed Tern. 



Geloehelidon nilotica gronvoliU Mathews, Birds Austr. ii. p. 331, 1912 



CArgentina). 

 Geloehelidon nilotica Braboume &. Chubb, B. S. Amer. i. p. 3.S, 



no. 32U, 1912. 

 Geloehelidon anylica (Mont.), Saunders, Cat. B. Brit. Mus. xxv. p. 25, 



1S96 (Demerara). 



Adult male. Head for the most part black intermixed with while, 

 Idacker on the nape and whiter on the forehead ; back and wings 

 silvery grey, the primaries darker towards the tips and more or 

 less white on the inner webs on the basal portion; outer pair of 

 tail-feathers inclining to white. '* Bill black, occasionally reddish 

 at the base of the lower mandible ; iris hazel-brown ; hirsi and 

 toes black with a reddi^h tinge ; webs moderately indented." 



