To this species Azara gives the name of _Pepoazá_, 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 _Tænioptera_, comprising eight known species. Most of these birds have some conspicuous wing-mark. They inhabit the southern portion of the South-American continent, 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 manner; but they also occasionally pursue and capture insects on the wing, like the typical Tyrant-birds that seldom or never alight on the ground. They have likewise another and unique preying-habit, intermediate between the Plover-like habits of _Agriornis_, _Myiotheretes_, and _Muscisaxicola_, and the Swallow- or Flycatcher-like habits of the true Tyrants. The bird perches itself on an elevation--the summit of a stalk, or bush, or even of a low tree--to watch like a Flycatcher for its insect prey; only instead of looking about for passing insects, it gazes intently down at the ground, just as a Kingfisher does at the water, and when it spies a beetle or grasshopper, darts down upon it, not, however, to snatch it up with the bill as other Tyrants do, but it first grasps it with its feet, then proceeds to despatch it, swaying about and opening its wings to keep its own balance, just as an Owl is seen to do when it grasps a mouse or other small animal in its claws. After devouring the insect on the spot, it flies back to its perch to resume the watch. They are very restless, active, playful birds, and seldom remain long on one spot, apparently finding it irksome to do so; but I have seen the _T. irupero_ occupy the same perch for hours every day while looking out for insects. As an English generic name for this small interesting group might be useful, I would suggest _Ground-gazers_ or _Ground-watchers_, which describes the peculiar preying-habit of these birds. The Pepoazá is a swift, active, graceful bird, with a strong, straight beak, hooked at the point, and a broad tail four inches long, the total length of the bird being nine inches. The throat and space between the beak and eye are white; all the rest of the body, also the wing- and tail-coverts, light grey; tail and wing-quills black, with a pure white band across the base of the primaries. The tertiaries and rectrices are tipped with pale rufous grey.