560 PROCEEDINGS OF THE NATIONAL MUSEUM VOL, 97 
He writes that the nominate form occurs in French, Dutch, and 
British Guiana, ‘‘west to the adjoining parts of Venezuela (Orinoco 
Delta and Caura Valley) south to the north bank of the lower Amazon, 
Brazil (Obidos, Manaos),’”’ while he records brevipes from the upper 
stretches of the Rio Negro to eastern Peru. In other words, Hellmayr 
suggests that brevipes occurs on the Upper Rio Negro while surinamus 
is the bird to the north of it in the Caura Valley and also to the 
south of it at Mandos. I have seen no birds from either locality, 
but the present series agree with topotypical ‘‘Bogota”’ brevipes and 
differs from typical Guianan examples of surinamensis. Hither 
Caura Valley birds are more or less intermediate or the line of demar- 
cation between the races in southern Venezuela must be between the 
valleys of the Caura and the Upper Orinoco, an area which does not 
seem to function as a limiting boundary for races of many other birds. 
Immature females are not different in coloration from adults. 
Two additional birds from Sao Gabriel were preserved in alcohol. 
HEMITHRAUPIS FLAVICOLLIS AURIGULARIS Cherrie: Golden-throated Tanager 
Hemithraupis flavicollis aurigularis CHERRIE, Bull. Amer. Mus. Nat. Hist., vol. 
35, 1916, p. 389 (Suapuré, Caura River, Venezuela). 
SPECIMENS COLLECTED 
lad. 9, Salto do Hud, Venezuelan berder, Brazil, November 16, 1930. 
2 ad. 9, Sao Gabriel, Rio Negro, Amazonas, Brazil, December 31, 1930 and 
January 1, 1931. 
1 ad. 9, Chapazon, Brazo Casiquiare, Venezuela, January 30, 1931. 
lad. @,3im. o&, Cerro Yapacana, Upper Orinoco, Venezuela, April 8-17, 1931. 
The three supposedly immature males from Cerro Yapacana are 
very different inter se, and suggest, if correctly sexed, that the male, 
at least, of this form goes through a very complicated plumage cycle. 
One of them (U.S.N.M. No. 329389) resembles the adult females but 
has the crown and occiput slightly darker; another (U.S.N.M. No. 
329388) is similar to the first one but has the lower back, rump, and 
upper tail coverts yellow, not dark green; has the chin and throat 
brighter, more golden, yellow; and has some black remiges, upper 
wing coverts, and auriculars coming in; the third one is like the adult 
male, but has the yellow of the back, rump, and upper tail coverts a 
little paler, less tinged with orange. It may be that the first of these 
is the true juvenal plumage, the second merely a stage of the post- 
juvenal molt, and the third the first adult plumage, differing from 
subsequent ones only in the shade of the yellow on the back and 
rump. ‘The females show less variability, the chief variable being the 
extent of yellowish suffusion on the abdomen. 
THLYPOPSIS SORDIDA ORINOCENSIS Friedmann: Orinoco Orange-headed Tanager 
Thlypopsis sordida crinocensis FRIEDMANN, Proc. Biol. Soc. Washington, vol. 55, 
1942, p. 85 (Isla Orocopiche, near Scledad, Orinoco River, Venezuela). 
