_Description._--Above olive-green; head more or less rufescent; front and superciliaries chestnut-red; sides of head grey, beneath pale ochraceous; breast and sides yellow; throat greyish; bill short and thick, pale reddish, with a black blotch at the base of the lower mandible; feet reddish: total length 6·5 inches, wing 3·3, tail 3·0. _Female_ similar. _Hab._ Paraguay and Northern Argentina. This species was met with by Durnford near Salta in June 1878. He describes the iris as "light rufous; upper mandible dark slate, under mandible, legs, and feet pale slate." Mr. Salvin founded his _C. altirostris_ upon Durnford's specimens, but Graf v. Berlepsch is of opinion that this species is the "_Habia verde_" of Azara, and should consequently bear the name "_viridis_" of Vieillot. This is perhaps correct, but at the same time it would only make fresh confusion to transfer to this species the name hitherto usually applied to the preceding bird. We prefer, consequently, to let it stand under Mr. Salvin's name "_altirostris_." Fam. VIII. HIRUNDINIDÆ, or SWALLOWS. The cosmopolitan family of Swallows, of which about eighty species are known, is well developed in the New World, where some thirty representatives occur in various parts. In Argentina the occurrence of eight Swallows has been recorded. Three of them belong to the group of Purple Martins (_Progne_), which is restricted to the New World, and of the remainder four are members of genera entirely restricted to the Neotropical Region. The genus _Petrochelidon_, of which one species is met with in La Plata, has alone representatives in the Eastern Hemisphere. 25. PROGNE FURCATA, Baird[3]. (PURPLE MARTIN.) +Progne purpurea+, _Hudson, P. Z. S._ 1872, p. 548 (Patagonia); _Scl. P. Z. S._ 1872, p. 605; _Scl. et Salv. Nomencl._ p. 14; _Durnford, Ibis_, 1877, p. 32 (Chupat), 1878, p. 392 (Central Patagonia); _White, P. Z. S._ 1882, p. 595 (Buenos Ayres). +Progne elegans+, _Barrows, Bull. Nutt. Orn. Cl._ viii. p. 89 (Bahia Blanca). +Progne furcata+, _Baird, Rev. A. B._ p. 278; _Sharpe, Cat. A. B._ x. p. 175. _Description._--Uniform deep purple-blue; on each side of the back a small concealed tuft of white feathers; tail-feathers black, washed with blue: total length 7·7 inches, wing 5·55, tail 3·3. _Female_: upper parts dull purple; head, neck, and lower parts blackish brown. _Hab._ Argentina and Patagonia.