4.40 BIRDS OF BRITISH GUIANA. 



seeds, and hence are called by the common name, Grass-birds, 

 though they are often seen among the trees and on the ground. 

 They are nearly all referable to the genus SpermopMla. 



Genus DUNCANULA Chubb. 



Duncanula Chubb, Ann. & Mag. Nat. Hist. (ser. x.) p. 193, Feb. 1921. 

 Type D. homochroa (Sclater). 



The chief character in this genus is the long and acutely pointed 

 bill. The wing is rounded, the third, fourth, and fifth primaries 

 longest and equal, the second about equal in length to the sixth, 

 and the first about equal to the eighth. The tail is square at the 

 tip and about five-sixths the length of the wing. The tarsus is 

 about equal in length to the middle toe and claw, which are about 

 twice the length of the exposed culmen. Coloration : male and 

 female similar. 



628. Duncanula duncani. 



Duncan's Seed-batek. 



(Plate VII.) 



Catamenia sp. Salvin, Ibis, 1885, p. 216 (Eoraima, 6000 ft.). 

 Spermophila homochroa (part nee Scl.) Sharpe, Cat. B. Brit. Mus. xii. 



p. 105, 1888 (Eoraima). 

 Catamenia homochroa Brabourne & Chubb,' B. S. Amer. i. p. 368, no. 3774 



(part), 1912. 

 Duncanula duncani Chubb, Ann. & Mag. Nat. Hist. (ser. x.) p. 193, 



Feb. 1, 1921. 



Adult male. General colour of the upper surface olive-brown 

 with dark shaft-lines to the feathers, including the top of the head, 

 entire back, wings, and tail, somewhat darker on the head and 

 tinged with dark slate-grey on the upper wing-coverts; flight- 

 quills blackish rather paler on the inner margins, outer webs of 

 secondaries tinged with smoke-brown ; tail-feathers blackish 

 fringed with olive-brown ; sides of face, sides of neck, throat, 

 fore-neck, and under wing-coverts dark slate-grey ; abdomen and 

 sides of body olive-brown, the feathers surrounding the vent 

 tipped with pale rufous ; under tail-coverts chestnut ; under 



