156 BIRDS OF LA PLATA 
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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 
successively 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 surrounding 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. 
Three more species of this curious genus have 
been found in Argentina, but unfortunately their 
discoverers have told us nothing of their habits. 
