528 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 97 
SPECIMENS COLLECTED 
3ad. #, lad. 9, Venezuela, Brazo Casiquiare, Playa de Candela, February 8, 
1931. 
1 ad. ?, Venezuela, Brazo Casiquiare, below mouth of Rfo Pacila, February 
11, 1931. 
lad. &, Venezuela, Brazo Casiquiare, February 13, 1931. 
lad. @, lim. 9, Venezuela, Brazo Casiquiare, near Cafio Matipin, February 
18, 1931. 
lad. 2, Venezuela, Tamatama, Upper Orinoco, February 23, 1931. 
1 ad. o&, Venezuela, Upper Orinoco, near Cerro Cariche, February 24, 1931. 
3 ad. o, Venezuela, Puerto Ayacucho, Rfo Orinoco, May 11-15, 1931. 
lad. 2, lim. 9, Venezuela, Puerto Ayacucho, Rio Orinoco, January 3-5, 1930. 
This fine series of bogotensis has been compared with specimens of 
zuliensis, venezuelanus, albipectus, hypoleucus, and leucotis. Birds 
from the Brazo Casiquiare average slightly darker above than do 
Orinoco examples, but the difference is very small and not entirely 
constant. 
THRYOTHORUS CORAYA GRISEIPECTUS Sharpe: Gray-breasted Wren 
Thryothorus griseipectus SHARPE, Catalogue of birds in the collection of the British 
Museum, vol. 6, 1881, p. 236, pl. 15, fig. 1 (Nauta, Ecuador). 
SPECIMENS COLLECTED 
lad. &, Brazil, Rio Cauabury, Amazonas, November 3, 1930. 
lad. #7, 2ad. 9, Brazil, Rio Maturac4é, Amazonas, November 6-11, 1930. 
1im.-, Brazil, Salto do Hud, Rio Maturacdé, November 20, 1930. 
3 ad. #, 2 im. o, Brazil, Sao Gabriel, Rio Negro, Amazonas, December 27, 
1930—January 9, 1931. 
1 ad. 9, Brazil, Rio Negro Islands below San Carlos, Amazonas, January 27, 
1931. 
2ad. #,2ad. 9, Brazil, Cucuhy, Rio Negro, Amazonas, February 3-8, 1930. 
lad. 9, Venezuela, Cerro Guanari, Brazo Casiquiare, February 4, 1931. 
lad. &, lad. 9, Venezuela, Brazo Casiquiare, below Cafio Caripo, February 
22, 1931. 
Hellmayr (Catalogue of the birds of the Americas, pt. 7, 1934, p. 193) 
gives the wing length of this form as 60-65 mm. in males, 58-60 mm. 
in females. This is greater than the measurements of the present 
series, which run from 54 to 62.5 mm. in the males, and from 54 to 58 
mm. in females. All these specimens come from the general area 
from which Hellmayr notes the birds have smaller bills and are some- 
what deeper chestnut above. Within the series there are no significant 
geographic variations. It may be noted, however, that all the adult 
females have the forehead, crown, occiput, and nape considerably 
paler, more rufescent, less blackish, than a fairly topotypical one from 
Rio Pastaza, Ecuador. The same difference does not hold for males 
from the two regions, however. 
Of the three birds labeled as immature, two are not readily dis- 
tinguishable from adults. One, however, is much darker on the breast 
