I50 BROOKLYN IXSTITUTE MUSEUM. SCIENCE BULLETIN 2. 6. 
Mr. Hellmayr, who has made a careful study of the South Ameri- 
can members of the genus Polioptila, has, in his last word on the 
subject', concluded that there are six recognizable races of P. livida. 
Only one of this number has been recorded from the Orinoco 
region but as there are two others whose geographical distribution 
when better known may be found to extend to the territory under 
consideration, 1 have included them in the following key. 
Key to Subspecies of Polioptil.a livida. 
a. Outer tail-feathers black at base of both inner and outer webs Polioptila livida plumhiceps. 
a'. Outer tail-feathers entirely white. 
b. Upper wing-coverts edged with whitish and broad white edgings of the 
tertials reaching almost to the shaft. (Cayenne. Surinam , Lo%ver Ama- 
zonia from Para to Santarem) Polioptila livida livida. 
b'. LTpper wing-coverts edged with pale bluish grey and white edges to 
tertials much narrower. (British Guiana. Rio Branco in North Brazil) Polioptila livida innotata. 
Polioptila livida plumbiceps (Lawrence). 
PoUot^tila phnnhiccps Lawrence, Proc. Acad. N. Sc. Phila. XVIL 1865. 
p. 37 ( \'enezuela). 
Polioptila nigriccps Berlepsch & Hartert ( non Baird) p. 9. 
P[olioptila] livida plumbiceps Hellmayr, Novit. Zool. XIV, 1907. p. 4. 
This species is common along the Middle Orinoco from Ciudad 
Bolivar to the Falls of Atures, and less abundant above the falls 
where specimens were collected at Maipures. 
A nest of this species, wdiich the young were just leaving, was 
found at Caicara June 20, 1907. It closely resembled nests of the 
Blue-grey Gnatcatcher of Eastern North America, being a neat, trim, 
lichen-covered cup, saddled on to a horizontal branch. The nest 
measures outside : depth 45, diameter at middle of nest, 53 : inside: depth 
31; diameter at rim 35; diameter half way down 41 mm. It was about 
5 m. from the ground on one of the branches of a Chaparo oak 
that stood near the edge of the open savanna. It is by merest chance 
that such a nest is discovered as it is so small, so inconspicuous and 
its lichen covered walls match so exactly the color of the branch on 
which it rests.2 
'Novitates Zoologicae XIV. 1907. pp. 4-5- 
-\t seems somewhat doubtful to the writer if the nest described as that of Lawrence's Gnatcatchei 
by Clark (Auk XIX. 1902. p. 266.) from Margarita Island could have belonged to that species. Gnat- 
catcher nests certainly do not resemble those of the yellow Warbler. 
