96 BIRDS OF BRITISH GUIANA. 



quills blockish ; tail, hind-neck, and entire under surface white. 

 " Bill lake-red, tarsi and toes dull red." 



Total length 435 mm., culmen 45, wing 310, tail 122, tarsus 50. 



Adult female^ Similar to the adult male. Wing 299. 



Immature. Differs from the adult in being brown on the upper 

 surface, in having no white on the hind-neck nor on the tail- 

 feathers. 



The descriptions are taken from specimens obtained on the 

 Abarj River. 



Breeding-season. Unknown in British Guiana. 



Nest. Unrecorded in British Guiana. 



Eggs. Undescribed from British Guiana. 



Range in British Guiana. Abary River (McConnell collection) ; 

 Georgetown Harbour (Beebe) ; British Guiana [Schomhurgk Sf 

 Wliitehj) ; Georgetown {Quelch). 



Extralimital Range. Surinam (Penard), Trinidad, Venezuela 

 and the adjacent islands. North Brazil, and Peru. 



Ifahits. Schomburgk states that he found this bird along the 

 coast. 



Genus STERCORARIUS Briss. 



^tercorarius Brisson, Orn. vi. p. 149, 17G0. Type S. parasiticus Linn. 



This genus is distinguished from Larus in having a cere, a 

 hook at tiie tip of the upper mandible, strong and sharply-hooked 

 claws, and bj' the middle tail-feathers projecting far bevond the 

 outer ones. 



60. Stercorarius pomarinus. 



POMATORHINE SkUA. 



Stercoravivs jyomarinus (Temm.), Man. d'Orn. p. .514, 181-5 (Coast of 

 Sweden) ; Braboiu-ne & Chubb, B. S. Amer. i. p. 36, no. 353, 1912. 



Stercorarius pomatorhinus Saunders, Cat. B. Brit. Mus. xxv p 322 

 1896. 



Mecjalestris chUensis Penard, Vog. Guyana, i. p. 18 (Britisli Guiana). 



Immature. Upper surface brown, with buff or rufous-buff 

 edgings to the leathers; tail uniform brown; quills blackish, 

 white on the inner webs at the base, shafts white at base, brown 

 at the tips ; under surAice paler brown than the back, with rufous 

 cross-bars on the fore-neck and breast, which are less distinct 

 on the throat and broader and whiter on the abdomen, Hanks, and 

 under tail-coverts. 



