(SLATY-BLUE BUSH-BIRD.)
+Thamnophilus cærulescens+, _Burm. La-Plata Reise_, ii. p. 472
(Paraná, Mendoza, Tucuman); _Scl. et Salv. Nomencl._ p. 70;
_White, P. Z. S._ 1882, p. 614 (Corrientes, Misiones); _Barrows,
Auk_, 1884, p. 21 (Entrerios); _Salvin, Ibis_, 1880, p. 361
(Salta).
_Description._--Above grey, black on the crown, and a patch of white
and black feathers on the middle of the back; wings black, the
coverts thickly spotted and the inner webs of the remiges edged with
white; tail black, all the feathers, except the middle pair, tipped
with white, the outer rectrix on each side has also a long white
spot in the middle part of the outer web; beneath cinereous, white
on the belly; bill and feet black: whole length 5·6 inches, wing
2·7, tail 2·3. _Female_: above earthy olive-green, yellowish on
the crown; wing-coverts and tail as in the male; wing-feathers
olive-brown; beneath yellowish olive-grey, brightening into
ochraceous on the belly and flanks.
_Hab._ Paraguay and Argentina.
Mr. Barrows says concerning this species that it is "frequently seen,
especially during the winter" (on the Lower Uruguay). A nest, taken
November 24th, "was almost precisely like that of our Red-eyed Vireo
(_V. olivaceus_), being pensile in the fork of a horizontal spray, only
four feet from the ground. It contained three fresh eggs, white, with
spots and dashes of light brown."
White says that these birds frequent the banks of streams, and have a
deep bass call-note, rather mournful and slow.