_Description._--Above hoary grey, with lineiform blackish shaft-stripes; wings black, with large chestnut-brown patch occupying the outer webs of the inner primaries; tail of twelve much graduated feathers, black; outer web of external rectrices white; beneath same as above, but rather paler; throat and crissum white; patch on each side of the neck, and collar across the neck dark chestnut-brown; under wing-coverts and inner webs of wing-feathers white; bill pale brown; feet black: whole length 16·0 inches, wing 5·0; tail, extreme rectrix 12·5, middle 2·6. _Female_ similar, but less bright. _Hab._ S.E. Brazil, Paraguay, Bolivia, and Northern Argentina. Azara found this singular species not uncommon in Paraguay, and since his brief notice of it in the 'Apuntamientos' nothing concerning its habits has been recorded. It has a somewhat laboured flight, he says; lives in pairs or families, frequenting low or marshy grounds, where it perches on the summit of the reeds or bushes, and flies down to the ground to capture insects. It also occasionally dashes after passing insects, taking them on the wing. It has a loud whistle, which it utters frequently without any variation. 125. SISOPYGIS ICTEROPHRYS (Vieill.). (YELLOW-BROWED TYRANT.) +Sisopygis icterophrys+, _Hudson, P. Z. S._ 1868, p. 141; _Scl. et Salv. Nomencl._ p. 43; _Durnford, Ibis_, 1877, p. 176 (Buenos Ayres); _Gibson, Ibis_, 1880, p. 29 (Buenos Ayres): _White, P. Z. S._ 1882, p. 604 (Buenos Ayres); _Barrows, Bull. Nutt. Orn. Cl._ viii. p. 141 (Entrerios). +Tænioptera icterophrys+, _Burm. La-Plata Reise_, ii. p. 460 (Paraná). _Description._--Above bright olive-green, head rather greyish, lores and superciliary stripes yellow; wings blackish, broad ends of coverts and outer edges of secondaries dirty white; tail blackish; beneath bright yellow, sides of breast and flanks olivaceous; under wing-coverts whitish; bill dark horn-colour; feet black: whole length 6·1 inches, wing 3·5, tail 2·7. _Female_ similar, but less bright. _Hab._ S.E. Brazil, Paraguay, Uruguay, Northern La Plata, and highlands of Bolivia and Peru. This small and pretty Tyrant-bird is quite common in the woods along the Plata, and is also seen a great deal in orchards and groves in the cultivated districts. In Buenos Ayres it is a summer visitor, appearing there in October, and is a shy, solitary bird, which catches insects on the wing, and rarely visits the ground. The nest is placed in a tree, ill-concealed, and very shallow: it is built of fine sticks, and lined with fine grass, horse-hair, and feathers. The eggs are four, pointed, pale cream-colour, with large dark red spots, chiefly at the larger end. The only language of this species is a very low plaintive whistle, uttered as a faint protest when the nest is approached.