+Euscarthmus gularis+, _Scl. et Salv. Nomencl._ p. 45; _White, P. Z. S._ 1882, p. 605 (Corrientes and Oran). _Description._--Olive-brown; wings blackish, wing-coverts tipped and outer secondaries edged with yellowish white, forming two distinct bands; remiges and rectrices narrowly margined with olive; head above dark cinereous; lores and sides of the head surrounding the dark ear-coverts rufous; beneath white, sides of the breast greyish; chin and sides of throat rufous, like the lores; flanks and under wing-coverts tinged with yellowish: whole length 3·5 inches, wing 1·8, tail 1·4. _Female_ similar. _Hab._ S.E. Brazil, Bolivia, and Northern La Plata. This bird was observed by White near Oran, and also in Misiones. 140. PHYLLOSCARTES VENTRALIS (Temm.). (YELLOW-BELLIED TYRANT.) +Phylloscartes ventralis+, _Scl. et Salv. Nomencl._ p. 46; _Barrows, Bull. Nutt. Orn. Cl._ viii. p. 198 (Entrerios). _Description._--Above uniform olive; ill-defined superciliaries whitish; ear-coverts dark; wings and tail blackish with olive margins; well-defined spots on the tips of the two rows of wing-coverts and outer webs of secondaries yellowish; below yellow, rather white on the throat and olivaceous on the sides; under wing-coverts pale yellow; bill and feet blackish: whole length 4·5 inches, wing 2·1, tail 2·3. _Hab._ S.E. Brazil and Northern La Plata. This species is stated to have been met with by Mr. Barrows among the low bushes bordering the streams of Entrerios. Graf v. Berlepsch has recorded its presence in Rio Grande do Sul (Zeitschr. ges. Orn. 1885, p. 131), so that this occurrence is not improbable. 141. HAPALOCERCUS FLAVIVENTRIS (d'Orb. et Lafr.). (REED-TYRANT.) +Arundinicola flaviventris+, _d'Orb. Voy., Ois._ p. 335, pl. xxxi. fig. 1. +Hapalocercus flaviventris+, _Burm. La-Plata Reise_, ii. p. 456 (Mendoza); _Scl. et Salv. Nomencl._ p. 46; _Durnford, Ibis_, 1877, p. 177 (Buenos Ayres), et 1878, p. 395 (Centr. Patagonia); _White, P. Z. S._ 1882, p. 605 (Buenos Ayres); _Barrows, Bull. Nutt. Orn. Cl._ viii. p. 199 (Entrerios). _Description._--Above mouse-brown; wings and tail rather darker, with edgings like the back; vertex more or less tinged with rufous; beneath yellow; under wing-coverts pale yellow; bill and feet black: whole length 4·0 inches, wing 2·0, tail 2·0. _Female_ similar. _Hab._ S. Brazil, Paraguay, Uruguay, La Plata, and Chili.