Male; olivaceous, with each feather of the back margined with yellow, especially on the rump; the top of the head, throat, wings and tail, black, the two latter margined more or less with yellow; the sides of the head and beneath the body bright yellow. Habitat, forests of Tierra del Fuego (_February_), Valparaiso (_September_). SUB-FAM.—FRINGILLINÆ. 1. AMMODRAMUS LONGICAUDATUS. _Gould._ PLATE XXIX. _A. vertice humeroque cinereo-fuscis, dorso pallescenti fusco, uropygio rufescenti-fusco tincto, plumis singulis strigâ mediâ fuscâ; tectricibus alarum majoribus, remigibus primariis secundariisque et caudâ nigrescentibus, cinereo albo externe marginatis; fronte, strigâ superciliari corporeque infra flavescentibus._ Long. tot. 5¾ unc.; _alæ_, 2⅜; _caudæ_, 3; _tarsi_, ¾; _rostri_, ⁹⁄₁₆. Crown of the head and shoulder, greyish brown; back, light brown, tinged with reddish brown on the rump, and with a stripe of dark brown down the centre of each feather; greater wing-coverts, primaries, secondaries, and tail blackish, margined externally with greyish white; forehead, stripe over the eye, and all the under surface, buff; bill black; feet brown. Young, or a bird after gaining its new plumage, differs in having the whole of the upper surface rich brown, with a tinge of olive and with a stripe of dark brown down each feather, and in having the wing coverts margined with reddish instead of greyish brown. Habitat, Monte Video (_November_), Maldonado (_June_). At Maldonado this bird frequented, in small flocks, reeds and other aquatic plants bordering lakes. In general habits, as well as in place of resort, it resembles those species of Synallaxis and Limnornis, with which it is often associated. It appears to live entirely on insects, and I found in the stomach of one which I opened various minute Coleoptera. Mr. Gould remarks, that the structure of this Ammodramus is very remarkable, for that it has a great general resemblance both in form and colouring to Synallaxis, although the thickness of its bill shows its relation to the Fringillinæ. In its habits it certainly is more allied to the former genus, than to its own family. 2. AMMODRAMUS MANIMBE. _G. R. Gray._ PLATE XXX. Ammodramus xanthornus, in Plate, and in Gould’s MS. Fringilla Manimbè, _Licht._, Cat. No. 253. Emberiza Manimbè, _D’Orb. & Lafr._, Syn. p. 77. Manimbè, _Azara_, No. 141. My specimen was obtained from Maldonado. [Illustration: _Birds. Pl. 29._ _Ammodramus longicaudatus._ ] [Illustration: _Birds. Pl. 30._ _Ammodramus xanthornus._ ] 1. ZONOTRICHIA MATUTINA. _G. R. Gray._