This Flycatcher is by no means common in Catamarca. It is seen about the houses in pairs, but not more than one pair at a time at one dwelling, perched upon some projection, whence it darts off into the air at passing insects. "The snap of its beak, as it dashes at the flies, can be heard a long way off. Its cry is peculiar and piteous. There is no perceptible difference in plumage between the male and female."--_White, l. s. c._ 161. MYIOBIUS NÆVIUS (Bodd.). (LITTLE BROWN TYRANT.) +Myiobius nævius+, _Scl. et Salv. Nomencl._ p. 51; _White, P. Z. S._ 1882, p. 607 (Buenos Ayres); _Barrows, Bull. Nutt. Orn. Cl._ vol. viii. p. 201 (Entrerios). _Description._--Above brown; lores whitish; concealed vertical crest red or yellow; wings blackish, two bands across the coverts and outer margins of external secondaries pale rufous or fulvous, sometimes whitish; tail dark brown: beneath fulvous white; sides of throat, breast, and flanks more or less distinctly flammulated with brown; under wing-coverts pale fulvous; bill brown; lower mandible whitish; feet blackish: whole length 4·7 inches, wing 2·5, tail 2·3. _Female_ similar, but crest yellow or absent. _Hab._ Veragua and Cisandean South America down to Argentine Republic. This small Tyrant-bird is a summer visitor in the Plata district; it is shy and solitary; frequents woods and plantations, and perpetually utters, like the English Redstart, its sorrowful monotonous plaint, as it flits about in the upper foliage of the trees. The nest is placed in a bush or low tree, and built of various soft materials compactly woven together, and the inside lined with feathers or vegetable down. The eggs are four, pale cream-colour, with large, well-defined spots of dark red. The total length of this species is less than five inches. The prevailing colour of the plumage is rufous brown on the upper, and whitish brown on the under surface. Beneath the loose feathers of the crown there is a concealed spot of orange-red. 162. PYROCEPHALUS RUBINEUS (Bodd.). (SCARLET TYRANT.) +Pyrocephalus rubineus+, _Scl. et Salv. Nomencl._ p. 51; _Hudson, P. Z. S._ 1872, p. 808; _Durnford, Ibis_, 1877, p. 178 (Buenos Ayres); _Gibson, Ibis_, 1880, p. 27 (Buenos Ayres); _Barrows, Bull. Nutt. Orn. Cl._ vol. viii. p. 201 (Entrerios). +Pyrocephalus parvirostris+, _Burm. La-Plata Reise_, ii. p. 456 (Entrerios). _Description._--Above very dark cinereous, crested head and body below scarlet; bill and feet black: whole length 5·2 inches, wing 2·9, tail 2·3. _Female_ above paler cinereous, below white; breast striated with cinereous; belly more or less rosy red. _Hab._ S. America, from Colombia down to Buenos Ayres. It is in vain, I think, to attempt to make more than one species out of this widely-spread bird, though specimens from the west coast are usually smaller.