﻿428 PROCEEDINGS OF THE NATIONAL MUSEUM vol. loo 



eastern idoneus is without a name. Our Cantaura birds do not lend 

 themselves readily to a third possibility, that eastern "idoneus" and 

 erythropus are all one variable form. Under the circumstances, how- 

 ever, it seems better not to name the Cantaura idoneus but merely to 

 present the data, inasmuch as the differences in treatment in the 

 literature are less divergent factually than their nomenclatorial results 

 might seem to indicate. 



In size the Cantaura birds agree with northern Colombian idoneus. 

 Aside from the noticeably grayer hind neck the Venezuelan birds differ 

 from the Colombian ones in having the abdomen paler. 



It is always a cause for wonder when two apparently very similar 

 forms mth similar habits occur together. The junior author is of the 

 opinion that the woods at Caicara are sufficiently isolated (for a 

 sedentary bird like a tinamou) from the forests at Cantaura by the 

 intervening savanna to allow the two species to be separated in reality 

 although geographically near each other. The Caicara forest where 

 Crypfurellus noctivagus erythropus was collected was somewhat heavier 

 than the deciduous seasonal woods, as described in the introduction, 

 and was not quite the same as the lowland seasonal forest there 

 described. 



Family COLYMBIDAE: Grebes 



COLYMBUS DOMINICUS SPECIOSUS (Lynch Arribalzaga) 



Podiceps speciosus Felix Lynch Arribalzaga, La Ley, Buenos Aires, July 2, 

 1877, p. 1 (Baradero, Buenos Aires, Argentina). 



SPECIMEN COLLECTED 



1 cf, Caicara, June 12, 1948; gonads somewhat enlarged; iris yellow, bill 

 blackish, feet dark blue-gray; gizzard contained remains of what seemed to be 

 tadpoles; plumage shghtly worn. 



This specimen agrees with others from Venezuela and from farther 

 south. 



This small grebe was recorded on many of the savanna ponds during 

 the months of May through September, up to 10 individuals being 

 seen at one time. It was commoner around Caicara, where the 

 semipermanent ponds are larger and more numerous than at Cantaura. 



A floating nest of this bird was found on one of these ponds during 

 the third week of June. It contained three white eggs, two stained 

 brown by the decaying vegetation, the other apparently freshly laid. 



Local name, "patico zambullidor," little diving duck. 



PODILYMBUS PODICEPS ANTARCTICUS (Lesson) 



Podiceps antarcticus Lesson, Rev. Zool., 1842, p. 209 (Valparaiso, Chile). 



SPECIMEN collected 



1 cT, Caicara, June 20, 1948; gonads enlarged; iris brown, bill gray with black 

 bar; gizzard contained dragonfly larvae and a large beetle. 



