_Description._--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: whole length 8·0 inches, wing 4·2, tail 3·3. _Female_ similar, but yellow crest not so much developed. _Hab._ Bolivia, S. Brazil, Uruguay, and Argentina. 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 disposition than are the Silver-bill, already described, and the Bienteveo; the former being like an automaton, having only a few set motions, gestures, and instincts, while the other is versatile in an extraordinary degree, and seems to have studied to advantage the various habits of the Kestrel, Flycatcher, Kingfisher, Vulture, and fruit-eating Thrush; and when its weapons prove weak it supplements them with its running. How strange it is that these two species, mentally as widely separated as the Humming-bird and Crow, should be members of the same family! The Bienteveo has a wide range in South America, and inhabits the whole of the Argentine country down to Buenos Ayres, where it is very common. It is resident and lives in pairs, the sexes being always faithful. The body is stout, somewhat large for a Tyrant-bird; the length being nine and a half inches, including the beak, which is a little over an inch in length. The wings are blunt and comparatively short, measuring, when spread, fourteen inches. The head is large, and a broad, black band extends from the beak its entire length, and above this is a pure white stripe; the crown is black, concealing in its loose, abundant feathers a brilliant yellow crest, which shows only when the bird is excited. The upper plumage, including wings and tail, is pale brown; the entire under surface sulphur-yellow. In both sexes the plumage is alike.