The Marsh-Wren has a sweet and delicate song, resembling that of the House-Wren (_Troglodytes furvus_), but much less powerful. It does not migrate; and on the pampas I have heard it singing with great animation when the pampas-grass, where it sat perched, was white with frozen dew. Probably its song, like that of _Troglodytes furvus_, varies in different districts; at all events, the pampas bird does not possess so fine a song as Azara ascribes to his "Todo Voz" in Paraguay, which is undoubtedly the same species. Fam. V. MOTACILLIDÆ, or WAGTAILS. The Wagtails and Pipits are closely-allied forms, and are usually referred to the same family of Oscines. The Wagtails are restricted to the Old World, although it has been recently ascertained that some of them occasionally occur as stragglers in the northern latitudes of America. Of the almost cosmopolitan Pipits about eight or nine species are sparingly distributed over the prairies and pampas of the New World. One of these is a common resident in the pampas of Argentina, and another (perhaps somewhat doubtful species) is occasionally met with. 15. ANTHUS CORRENDERA, Vieill. (CACHILA PIPIT.) +Anthus correndera+, _Scl. et Salv. Nomencl._ p. 8; _Hudson, P. Z. S._ 1873, p. 771 (Buenos Ayres); _Durnford, Ibis_, 1877, p. 32 (Chupat), p. 168 (Buenos Ayres), 1878, p. 392 (Central Patagonia); _Sclater, Ibis_, 1878, p. 362; _White, P. Z. S._ 1882, p. 594 (Buenos Ayres); _Döring, Exp. al Rio Negro, Zool._ p. 37 (Azul); _Barrows, Bull. Nutt. Orn. Cl._ viii. p. 87 (Concepcion, Entrerios); _Sharpe, Cat. B._ x. p. 610. +Anthus rufus+, _Burm. La-Plata Reise_, ii. p. 474 (Mendoza, Paraná); _Durnford, Ibis_, 1876, p. 158. _Description._--Above pale sandy buff, mottled with black centres to the feathers; wing- and tail-feathers dark brown, edged with buff, the penultimate tail-feather with a white tip, the outer tail-feather almost entirely white; neck and breast sandy buff, with large triangular black spots; flanks buff, streaked with black; abdomen and under tail-coverts isabelline; bill dusky grey; feet pink: total length 6·0 inches, wing 2·9, tail 2·3. _Female_ similar. _Hab._ Paraguay, Argentina, Patagonia, and Chili.