532 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 97 
Americas, pt. 7, 1934, p. 386, footnote). Thus, the two males from 
the Brazo Casiquiare are different enough to suggest two races but for 
the fact that they both were taken in the same area at the same time. 
One is very much more rufescent and darker than the other. The 
two birds from the Upper Orinoco resemble the paler of the Brazo 
Casiquiare males. It is obvious from these few birds that great 
series are needed before we can determine whether or not the geo- 
graphic variations exceed individual variability in this form. For the 
present, at least, it may be well to follow Hellmayr in considering 
fredericki Chubb and abariensis Chubb as synonyms of fumigatus. 
TURDUS IGNOBILIS ARTHURI (Chubb): Arthur’s Black-billed Thrush 
Planesticus arthuri Couns, Bull. Brit. Orn. Club, vol. 33, 1914, p. 131 (Abary 
River, British Guiana). 
SPECIMEN COLLECTED 
1 ad. o&, Venezuela, Cerro Yapacana, Upper Orinoco, April 11, 1931. 
This lone specimen appears to belong to the present race, which I 
have otherwise seen from the lowlands of Duida and from Rio Negro, 
and constitutes a slight extension of the known range of the form 
westward, the previous westernmost point in Venezuela from which 
it had been reported being the base of Mount Duida. It also fits the 
colored illustration in Chubb’s “Birds of British Guiana” (vol. 2, 
1921, pl. 5, fig. 2) except that it does not have the throat nearly as 
white as in the plate. Its dimensions are as follows: wing 105; tail 78; 
culmen from the base 21 mm. It is a very worn plumage and is for 
this reason slightly paler than any of the other specimens seen. 
TURDUS LEUCOMELAS ALBIVENTER Spix: Spix’s Thrush 
Turdus albiventer Spix, Avium species novae . . . Brasiliam. . ., vol. 1, 1824, 
70, pl. 69, fig 2 (Pard, Brazil). 
SPECIMENS COLLECTED 
lad. 9, Venezuela, Laguna Icacal, Ciudad Bolivar, December 8, 1929. 
lad. 9, Venezuela, Ciudad Bolivar, June 10, 1931. 
lad. #, 2ad.?, Venezuela, Cerro Yapacana, Upper Orinoco, March 22—April 
3, 1931. 
lad. #@,2ad. 9, Venezuela, Puerto Ayaeucho, Rio Orinoco, January 10, 1930, 
and May 9-12, 1931. 
1 ad. #, 1 ad. 9, Venezuela, Soledad, Anzodtegui, November 29, 1929, and 
June 13, 1931. 
These specimens have been compared with three each from British 
Guiana, Venezuela, and Colombia, and with five from eastern Brazil 
(Bahia, Cearé, and Santarém). The differences shown by these 24 
birds do not warrant keeping epphipialis Sclater distinct from albi- 
venter, even when we bear in mind Hellmayr’s statement (Catalogue of 
the birds of the Americas, pt. 7, 1934, p. 401) that the differences be- 
tween the two, ‘‘while noticeable in series of freshly molted birds, are 
