(HUDSON'S BLACK TYRANT.)
+Cnipolegus hudsoni+, _Scl. P. Z. S._ 1872, p. 541, pl. xxxi. (Rio
Negro).
_Description._--Uniform dull black; a broad bar across the bases of
the inner webs of the wing-feathers white; two outer primaries much
pointed at their extremities; bill plumbeous, feet black: whole
length 6·0 inches, wing 2·8, tail 2·6.
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_, 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
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.