"This species frequently persecutes smaller birds in a way which seems to imply pure love of mischief. One afternoon in July, when the river had fallen some feet after an unusual rise, I was walking along the lines of drift left by the falling water, and watching the different birds which were picking up insects or other food from the wind-rows. A score or two of the little chestnut-backed _Centrites_ were running about, and here and there a _Tænioptera_ was looking quietly on. Suddenly I heard a chirp of distress, and looking up saw one of these small birds apparently making every effort to escape from a _Tænioptera_, which was following in full chase. The two birds were hardly a length apart and both going at full speed, doubling and dodging in a way that would have done credit to a bat. The chase lasted perhaps for half a minute, when the smaller bird alighted, and at once the other also alighted and began running about unconcernedly and picking up food. But the instant the smaller one made a start his enemy was at his heels (or more properly his tail) again, and he was forced to alight. This was repeated so often that I was on the point of shooting the pursuer, when, without any notice, he flew quietly off, and resumed his usual demeanour. It looked like a case of simple spite, for even if there were twenty other birds about, one seemed to be followed without regard to the rest." I have often watched _Tæniopteræ_ of different species, also _Myiotheretes rufiventris_ behaving in a similar way, and agree with Mr. Barrows that it is "an _amusement_ in which the larger bird indulges simply for the pleasure derived from the exercise of his power." 114. TÆNIOPTERA DOMINICANA (Vieill.). (DOMINICAN TYRANT.) +Tænioptera dominicana+, _Burm. La-Plata Reise_, ii. p. 460 (Entrerios); _Scl. et Salv. Nomencl._ p. 42; _Durnford, Ibis_, 1877, p. 176 (Buenos Ayres); _White, P. Z. S._ 1883, p. 38 (Buenos Ayres); _Döring, Exp. al Rio Negro, Zool._ p. 42 (Azul, Currumalan); _Barrows, Bull. Nutt. Orn. Cl._ vol. viii. p. 139 (Entrerios, Pigué, Pampas). _Description._--Above pure white; wings black, with a broad whitish subapical band across the first six primaries, beyond which the tips are blackish; tail black; beneath pure white: whole length 8·0 inches, wing 4·6, tail 4·2. _Female_ similar, but head above and back cinereous. _Hab._ S.E. Brazil, Paraguay, Uruguay, and Argentine Republic. This bird ranges from South Brazil and Paraguay to the southernmost pampas of Buenos Ayres. Its total length is eight inches. The wings and tail are black, the former barred with white; all the rest of the plumage in the male is pure white; in the female the upper parts are grey.