138 BIRDS OF LA PLATA 
all 
thistle-top or low bush, but never on trees. Their 
only language is a long, low, plaintive whistle, heard 
usually on warm, still days in winter. 
PEPOAZA TYRANT 
Tenioptera nengeta 
Above cinereous; lores white; wings black, coverts cinereous; a 
well-marked speculum at the base of the primaries and the edgings of 
the outer secondaries white ; tail black, tipped with whitish cinereous, 
basal one-third of tail white ; below pale cinereous, middle of throat 
white, with blackish stripe on each side; middle of belly, flanks, 
crissum, and under tail-coverts white; bill horn-colour ; feet black ; 
length 9 inches. Female smaller. 
To this species Azara gives the name of Pepoaza, 
the Guarani for Barred-wing ; and Pepoaza was used 
by him as a generic name for the small, well-defined 
group now placed in the genus Tenioptera, com- 
prising eight known species. Most of these birds 
have some conspicuous wing-mark. They inhabit 
the southern portion of the South American con- 
tinent, from South Brazil and Bolivia to the Straits 
of Magellan, and are most numerous on the open 
pampas and in Patagonia. In size they do not vary 
greatly, the largest being about nine inches long, 
the smallest about seven. In colour they are grey, or, 
more frequently, white relieved with black or grey, 
one species (T. rubetra) being rufous. Their legs 
are long, and they run on the ground like Myiotheretes 
rufiventris, feeding to some extent in the same 
