464 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 97 
SPECIMENS COLLECTED 
lad. @,1ad. 9, Brazil, Rio Negro, mouth of Rio Cauabury, October 21, 1930. 
lad. o, 1 ad. 9, 1-, Brazil, Cachoeira Thomaz, Rio Cauabury, October 27, 
1930. 
1 ad. 9, Brazil, Rio Cauabury, November 2, 1930. 
This bird is apparently locally rare or absent in many parts of its 
range, as the members of the expeditions met with it only during a 
period of less than two weeks, although it is known to occur from 
eastern Peru and eastern Eucador to western Amazonia and adjacent 
southwestern Venezuela. Zimmer (Amer. Mus. Nov., No. 558, 1932, 
p. 6) considers it possible that ‘‘there is an actual continuity of range 
over an extensive area but that the bird is locally rare or subject to 
ecological restrictions that are not yet understood.” 
DYSITHAMNUS ARDESIACUS OBIDENSIS Snethlage: Northern Slaty Ant-shrike 
Dysithamnus ardesiacus obidensis SNETHLAGE, Orn. Monatsb., vol. 22, 1914, p. 40 
(Obidos, north bank of Lower Amazon, northern Brazil). 
SPECIMENS COLLECTED 
lim. @, lim. 9, Brazil, Sio Gabriel, Rio Negro, December 26, 1930—January 
3, 1931. 
3 ad. o, lim. o’, 1 ad. - (9), Brazil, Salto do Hud, Rio Maturacé, November 
14-23, 1930. 
lad. #7, lim. &, lim. 9, Brazil, Serra Imeri, near Salto do Hud, November 
28-December 4, 1930. 
3 ad. o&, lad. 9, Venezuela, Cerro Yapacana, Upper Orinoco, March 18—April 
25, 1931. 
The immature males from Salto do Hué and Sao Gabriel are in 
adult plumage but have the throat pale as each of the black feathers 
is tipped with gray; the young male from Serra Imeri is, however, in 
the juvenal plumage. It is similar to the female in coloration but 
is considerably tinged with rufescent tawny both above and below. 
Immature females are like the adults. 
An alcoholic specimen from Estado Bolivar, December 30, 1929, 
may belong here, but is not certainly identifiable in its present condi- 
tion. 
THAMNOMANES CAESIUS GLAUCUS Cabanis: Guianan Slaty Bushbird 
Thamnomanes glaucus CaBanis, Arch. Naturg., vol. 13, 1847, p. 230 (Cayenne). 
SPECIMENS COLLECTED 
3 ad. o, lad. 9, Brazil, Cucuhy, Rio Negro, February 1-8, 1930. 
2 ad. 9, Brazil, Santa Isabel, Rio Negro, October 9-15, 1930. 
lad. ?, Brazil, Rio Cauabury, Cachoeira Thomaz, October 26, 1930. 
lad. 9, Brazil, Rio Cauabury, Destacamento, October 28, 1930. 
2 ad. o, Brazil, Rio Cauabury, Cachoeira, Manajé6, October 30-31, 1930. 
lad. 9, Brazil, Rio Cauabury, Panela de Onca, November 1, 1930. 
lad. &, lad. 9, Brazil, Rio Cauabury, November 5-6, 1930. 
5 ad. #7, 2im. o&, 2im. 3, Brazil, Salto do Hud, Rio Maturacd, November 
14-24, 1930. 
