D'Orbigny discovered this small Spine-tail near Buenos Ayres city, but did not record its habits. Like the species just described it is abundant on the pampas, but in its habits resembles a Wren of the genus _Cistothorus_ rather than a Pipit, being partial to moist situations, where there is a rank growth of grass and herbage. The wings are very short, and the flight so feeble that the bird refuses to rise after being pursued a distance of one or two hundred yards. And yet I am not prepared to say that it does not migrate, as I have found that in spring it all at once becomes very abundant, while in the cold season it is rarely seen. It is solitary, and in spring sits on a thistle or stalk, uttering at short intervals its small grasshopper-like song or call. The nest is a slight open structure of grass, lined with a few feathers, placed in a tuft of grass or reeds. The eggs are pure white in colour. 205. CORYPHISTERA ALAUDINA, Burm. (LARK-LIKE CORYPHISTERA.) +Coryphistera alaudina+, _Burm. La-Plata Reise_, ii. p. 470 (Paraná); _Scl. et Salv. Nomencl._ p. 64; _Salv. Ibis_, 1880, p. 359 (Tucuman, Salta); _White, P. Z. S._ 1883, p. 40 (Cordova). _Description._--Above dark greyish brown; elongated crest-feathers blackish; ear-coverts chestnut; on the back, upper tail-coverts, and upper wing-coverts the feathers have white and whity-brown edgings; wing-feathers blackish, the basal part of the inner webs pale brown; rectrices bright chestnut, broadly tipped with blackish; beneath white, thickly striated with fulvous brown; under wing-coverts pale cinnamon; bill and feet light brown: whole length 6·2 inches, wing 2·7, tail 2·3. _Female_ similar. _Hab._ Argentina. This highly interesting little bird, the only known member of its genus, inhabits the dry plains of Paraná and Cordova. The following meagre note from White, which only serves to excite curiosity, comprises all that we know of its habits:-- "These birds are not found in dense woods, but in the open, tenanted only by a few small trees or bushes. Five or six are usually seen running about together with a quick, abrupt movement, meanwhile uttering a sharp cry." 206. ANUMBIUS ACUTICAUDATUS (Less.). (FIREWOOD-GATHERER.) +Anumbius acuticaudatus+, _Burm. La-Plata Reise_, ii. p. 467 (Paraná, Mendoza); _Scl. et Salv. Nomencl._ p. 64; _Hudson, P. Z. S._ 1874, p. 159 (Buenos Ayres); _Durnford, Ibis_, 1877, p. 181 (Buenos Ayres); _White, P. Z. S._ 1882, p. 612 (Buenos Ayres); _Barrows, Bull. Nutt. Orn. Cl._ viii. p. 211 (Entrerios).