The Many-coloured Tyrant is, apparently, a very feeble flier, rising reluctantly when frightened from the rushes, and fluttering away to a distance of a few yards, when it again drops down. Yet it is strictly migratory. Darwin met with it at Maldonado in the month of June, and therefore concluded that it does not migrate; but he mentions that it was very rare. I have also occasionally seen one in winter on the pampas, but many migratory species leave a few stragglers behind in the same way. At the end of September they suddenly appear all over the pampas, in every swamp and stream where there are beds of rushes; for in such situations only is the bird found: and this migration extends far into Patagonia. They are always seen in pairs amongst the dense rushes, where they perch on the smooth stems, not near the summit, but close down to the surface of the water, and perpetually hop from stem to stem, deftly picking up small insects from the surface of the water. They also occasionally leave the rushes and search for insects in the grass and herbage along the border. They are very inquisitive, and if a person approach the rush-bed, they immediately come out of their concealment, both birds uttering their singular notes--a silvery, modulated sound, not meant for a song apparently, and yet I do not know any sweeter, purer sound in nature than this. All through the close-growing dark rushes the pretty little melodists may be heard calling to each other in their delicate, gurgling notes. The nest is a marvel of skill and beauty. As a rule it is attached to a single polished rush, two or three feet above the water and about the middle of the stem. It is cup-shaped inside, and about four inches long, circular at the top, but compressed at the lower extremity, and ending in a sharp point. It is composed entirely of soft bits of dry yellow rush, cemented together with gum so smoothly that it looks as if made in a mould. The eggs are two in number, oval, and dull creamy white, sometimes with a ring of colour at the large end. 151. LEPTOPOGON TRISTIS, Scl. et Salv. (SORRY TYRANT.) +Leptopogon tristis+, _Scl. et Salv. P. Z. S._ 1876, p. 254; _White, P. Z. S._ 1882, p. 606 (Misiones). _Description._--Above olive; cap rather darker; wings and tail blackish, margined with olive, the two rows of wing-coverts and three or four outer secondaries with clear yellowish-white apical spots; beneath pale sulphur-yellow; under wing-coverts yellow; inner margins of wing-feathers whitish: bill horn-colour; feet brown: whole length 4·4 inches, wing 2·1, tail 2·1. _Hab._ Northern La Plata and Bolivia. This bird was obtained by White near San Javier, Misiones, "amongst the lofty trees on the river-banks." White believed that he also met with it in the Sierra de Totoral. 152. ELAINEA ALBICEPS (d'Orb. et Lafr.). (WHITE-CRESTED TYRANT.)