416 BIRDS OF BRITISH GUIANA. 



Genus BASILEUTERUS Cab. 



Basileuterus Cabanis, Archiv fiir Naturg. 1847, i. p. '31G. Type 

 B. aiiricapilla (Swains.). 



The predominating colour in tbis genus is yellowish green on 

 the upper surface and yellow on the under parts. The bill is 

 some vhat short and stout, the width at the base bein^- about one 

 half the length of the exposed culmen. The wing is rounded, the 

 third, fourth, and fifth primaries longest and subequal, the second 

 is shorter than the fifth but longer than the sixth, and the first is 

 intermediate between the seventh and eighth. The tail is rounded 

 at the tip and rather more than five-sixths the length of the wing. 

 The tarsus exceeds the length of the exposed culmen by about 

 one half. Coloration : male and female similar. 



Key to the Species. 



A. Under surface yellow. 



a. Larger, wing more than 6-3 mm. ; back 



yellowish green ; crown of head more 



orange and less grey B. roraimce, p. 416. 



b. Smaller, wing less than 65 mm. ; back 



olive-green; more grey and less orange. B. olivascens, p. 417. 



B. Under surface white tinged with tawny 



buff B. mesoleucus, p. 418. 



611. Basileuterus roraimae. 



RoRAiMA Warbler. 



(Plate VI. fig. 2.) ^ 



Basileuterus roraimce Sharpe, Cat. B. Brit. Mus. x. p. 392, 1SS5 

 (Koraima, Merume Mts.) ; Salvin, Ibis, 1885, p. 203 (Merume Mts., 

 Koraima, 3500 to 6000 ft.) ; Brabourne & Chubb, B. S. Amer. i. 

 p. 359, no. 3678, 1912. 



Adult. Hind-neck, back, wings, and tail dark yellowish green ; 

 inner webs of flight-quills blackish brown, with pale inner edges; 

 nape grey ; sides of the face rather paler than the back, as are 

 also the sides of the neck and sides of the breast ; crown of head 

 orange-rufous ; a line of black feathers from the base of the fore- 

 head over the eye and along the sides of the crown ; a pale 

 supraloral line which skirts the black over the eye and along the 

 sides of the crown ; throat and remainder of the under surface 

 yellow with a dusky band across the breast; axillaries and under 

 wing-coverts pale yellow ; under surface of flight-quills hair- 

 brown ; lower aspect of tail yellowish. 



