Long. tot. 4 unc.; 11 lin.; rost. 5 lin.; alæ, 2¾; caudæ, 2¼; tarsi, 7 lin.
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).