GYMNODBRUS. 315 



feathers on the top o£ th^ head, the almost naked throat and neck, 

 and the lappets on the sides of the throat. Coloration : male and 

 female similar. 



551. Gymnoderus fcetidus. 



Bare-necked Geackle. 



Oracula fcetidus Linne, Syst. Nat. i. p. 164, 1766 (Guiana). 



Gymnoderus fcetidus Cab. in Schomb. Ileis. Guian. iii. p. 691, 1848 ; 

 Salvin, Ibis, 1885, p. 306 ; Sclater, Cat. B. Brit. Mus. xiv. p. 402, 

 1888 ; Bi-abourne & Chubb, B. S. Amer. i. p. 325, no. 3318, 1912. 



Adult male. General colour above and below black, including 

 the head where the feathers are very short and velvety, entire 

 back, upper tail-coverts, and tail on the upper surface, and the 

 throat where the feathers are short and sparsely distributed, 

 breast, abdomen, under tail-coverts, axillaries, and under winj;- 

 coverts on the under parts ; the small marginal upper wing-coverts 

 and outer webs of the bastard-wing black ; remainder of the 

 upper wing-coverts, innermost secondaries, and outer webs of 

 flight-quills silvery grey ; inner primary-coverts black, the outer 

 ones hoary grey; inner webs of flight-quills dark hoary grey; 

 under surface of quills and lower aspect of tail dark lead-colour. 



Total length 360 mm., exposed culmen 31, wing 215, tail 138, 

 tarsus 33. 



The bird described was collected in the Upper Takutu Moun- 

 tains in 1909. 



Adult female. Differs from the adult male in having the back 

 blackish tinged with dark slate-colour, the absence of silver-grey 

 on the wings (which are like the back), and its smaller size. Wing 

 192 mm. 



The specimen described is in the British Museum, and was 

 collected at Obidos, Lower Amazons, in June 1906 by F. Santos. 



Immature male. General colour both above and below bluish 

 black, with the white bases to the feathers on the back showing 

 through more or less, and the whitish margins to the upper wing- 

 coverts and the feathers on the under surface where the bases are 

 also white. This specimen was also collected on the Berbice 

 River. 



Breeding-season. Unknown in British Guiana. 



Xest. Unrecorded in British Guiana. 



