CNIPOLEGUS CYANIROSTRIS. 127 



This species is at once distinguishable from the preceding (C. anthracinus) 

 by its smaller size and the peculiar narrowed outer remiges. 



Hab. Northern Patagonia. 



This species is found in the western provinces of the Argentine 

 Republic, and, like C. anthracinus y which it closely resembles, is a 

 summer visitor in Patagonia, where it makes its appearance in October. 

 The plumage is intense black, with the inner webs of the remiges at 

 their base white, but the wing-band, which is over an inch in breadth, 

 shows only when the bird flies. There is also a small white spot on 

 the flank, scarcely visible, and excepting for this speck the bird at rest 

 appears entirely black. When it flies the white band appears suddenly, 

 producing a curious effect, for the wings are opened and shut suc- 

 cessively and with great rapidity, making the white band appear like a 

 succession of flashes. All the movements of the bird are eccentric to a 

 degree. It selects a dead twig on the summit of a bush, and this perch 

 it occupies during many hours every day. Occasionally it darts after 

 a passing insect, but I believe it feeds principally on the ground, 

 like Lichenops perspicillatus. At intervals it quits its perch very 

 suddenly and revolves round it with the rapidity of a moth whirling 

 round the flame of a candle, the wings producing a loud humming 

 sound, and the bird uttering a series of sharp clicking notes. During 

 this performance the white wing-band appears like a pale mist sur- 

 rounding the bird. This fantastical dance over, it resumes its perch, 

 and, until moved to a second display, sits as motionless as a bird carved 

 out of jet. 



128. CNIPOLEGUS CYANIROSTRIS (Vieill.). 

 (BLUE-BILLED TYRANT.) 



Cnipolegus cyanirostris, Burm. La-Plata Reise, ii. p. 457 (Mendoza) ; Scl et Salv. 

 Nomencl. p. 43 ; Barrows, Bull. Nutt. Orn. Cl. vol. viii. p. 141 (Entrerios). 



Description. Uniform dull black ; inner webs of the wing-feathers margined 

 with dull white ; bill plumbeous, feet dark brown : whole length 5-7 inches, 

 wing 3-0, tail 5-6. Female dark cinnamomeous brown, brighter on the head 

 and rump ; wings blackish, wing-coverts and secondaries edged with pale rufous ; 

 tail blackish brown, outer margins of outer rectrices and inner webs of all the 

 rectrices, except the two middle, bright rufous : below pale fulvous, densely 

 striated with blackish ; hill and feet brown. 



Hab. S. Brazil, Paraguay, Uruguay, and La Plata. 

 In size this species of Black Tyrant is but slightly smaller than the 

 one described, and the colour is also of an intense black, but the white 



