176 BIRDS OF LA PLATA 
long, circular at the top, but compressed at the lower 
extremity, and ending in a sharp point. It is com- 
posed entirely of soft bits of dry yellow sedge, ce- 
mented together with gum so smoothly that it looks 
as if made in a mould. The eggs are two, oval, and 
dull creamy white, sometimes with a ring of colour 
at the large end. 
BIENTEVEO TYRANT 
Pitangus bolivianus 
Above brown; head black; front, superciliaries, and line round 
the nape white ; large vertical crest yellow, tipped with black; wings 
and tail brown with rufous margins; beneath sulphur-yellow, inner 
margins of wing- and tail-feathers pale rufous; bill and feet black; 
length 9 inches. 
THE Bienteveo is in its habits the most interesting 
member of the Tyrannine family. It would be 
difficult to find two species more dissimilar in dis- 
position than are the Silverbill, already described, 
and the Bienteveo; the former being like an auto- 
maton, having only a few set motions, gestures, and 
instincts, while the other is versatile in an extra- 
ordinary degree, and seems to have studied to 
advantage the various habits of the Kestrel, Fly- 
catcher, Kingfisher, Vulture, and fruit-eating Thrush ; 
and when its weapons prove weak it supplements 
them with its cunning. How strange it is that these 
two species, mentally as widely separated as the 
