- 
BIRDS FROM BRAZIL AND SOUTHERN VENEZUELA—FRIEDMANN 377 
Negro to the Upper Orinoco is apparently the most important basic 
factor behind the present distributional picture of the local avifauna. 
It should not be assumed that there are no differences in the bird 
life of the Upper Rio Negro and of the Upper Orinoco, but the number 
of forms that break up into different races in the two areas is small 
indeed compared to the great number that do not. Many more 
species divide into races well down the Orinoco, but not between the 
Negro, the Casiquiare, and the Upper Orinoco. Among the species 
that do have separate subspecific groups in the two areas are the 
following: 
Sakesphorus canadensis: 
iS. ¢. loretoyacuensié_..-_.--_=...- Rio Negro. 
iS. 6: JUMNGUE. So ee ee Casiquiare, Upper Orinoco. 
Grallaria macularia: 
G. m.-pardenste®k Sale) 2.2... Rio Negro. 
Ge ms, diversa Biel: sete - nS 8 Casiquiare, Upper Orinoco. 
Sublegatus glaber: 
S:9. Sorduiusie ree Seti fn Rio Negro. 
S. 9. ortnocensten Sg e 2s. Casiquiare, Upper Orinoco. 
Phaeomyias murina: 
Po msebagge Mewes ae sce Rio Negro. 
PF: mitncomiaee. Sores las ee Casiquiare, Upper Orinoco. 
Cam ptosioma obsoletum: 
C.. 0, Wa pmeais Eee ae 8 Rio Negro. 
Oa Gene ede ages oe Oe 2. Upper Orinoco. 
Manacus manacus: 
Mme anteriores . 2s ae Stas 53s Rio Negro. 
M. m. umbrosu’ i... -2ccll cue. Upper Orinoco. 
The surprisingly few birds that range north to the Upper Rio Negro 
but not to the Casiquiare and the Upper Orinoco, birds like Myiozetetes 
luteiventris and Todirostrum maculatum annectens, may yet be found 
in the latter area, as the total bulk of collections made there is still 
not great. For this reason, it is well not to attempt to read any sig- 
nificance into these few instances. 
Of the 486 species and subspecies of birds in the collections here 
reported on, the following 10 were found to be new to science and have 
been described elsewhere: 
Brotogeris chrysopterus tenuifrons Fried- Formicivora grisea rufiventris Carriker 
mann Myrmeciza disjuncia Friedmann 
Nyctiprogne leucopyga exigua Friedmann Manacus manacus umbrosus Friedmann 
Nyctiprogne latifascia Friedmann Ateleodacnis margaritae Holt 
Reinarda squamata semota Riley Thlypopsis sordida orinocensis Fried- 
Capito auratus transilens Friedmann mann 
In addition to these novelties, 11 forms seem to be additions to the 
published records of birds for Venezuela, and 5 appear to be new to 
Brazil. The apparent additions to the Venezuelan avifauna are as 
follows: 
