As a rule, small seed-eating birds are beneficially affected by the presence of man; thus our common _Zonotrichia_ and other sparrows and finches have become excessively numerous in the most thickly-settled districts. With the Red-billed Finch, however, just the contrary has happened; and since I have known this species it has disappeared from many localities where it was once quite common. Azara's name for this species, _Habia de bañado_, signifies that it is a marsh bird; but though now found chiefly in marshy situations, it was once common enough over the entire pampas region, before the great plains were settled on by Europeans. The bird is very badly protected by nature against raptorial species, owing to its very conspicuous red beak, its habit of perching on the summit of tall plants and other elevated positions, its loud impetuous voice, which invites attention, and the weak eccentric flight, which challenges pursuit. It is essential to its safety that it should have, in the open country it frequents, a dense grass cover into which it can plunge on the slightest alarm. Where cattle are introduced, the original pampas-grass, which afforded the suitable conditions, disappears, giving place to the soft, perishable grasses, clovers, and thistles of Europe. Where these changes take place, the bird cannot escape from its enemies and quickly disappears; while many Dendrocolaptine species inhabiting the same situations are saved by their inconspicuous protective colouring, sharp wedge-like bodies, and swift mouse-like motions on the ground. In marshy places on the pampas, abounding with long aquatic grasses and reed-beds, the Red-bill still maintains its existence, but from its old habitat on the open grassy plains, where it was once the dominant Finch, it has utterly vanished. 84. EMBERNAGRA OLIVASCENS (d'Orb. et Lafr.). (OLIVE GROUND-FINCH.) +Embernagra olivascens+, _d'Orb. Voy., Ois._ p. 285; _Burm. La-Plata Reise_, ii. p. 485 (Mendoza); _Scl. et Salv. Nomencl._ p. 32; _Salvin, Ibis_, 1880, p. 355; _Döring, Exp. al Rio Negro, Zool._ p. 40 (R. Colorado). _Description._--Similar to _Embernagra platensis_, but the back unstriped, and the olive hue somewhat purer; also the abdomen of a paler buff: total length 8·1 inches, wing 3·7, tail 4·0. _Female_ similar. _Hab._ Bolivia, Western Argentina, and Patagonia. This species, which was met with by Dr. Burmeister near Mendoza, was found by Dr. Döring as far south as the Rio Colorado, on the pampas. 85. EMBERIZOIDES SPHENURUS (Vieill.). (WEDGE-TAILED GROUND-FINCH.) +Embernagra macroura+, _d'Orb. Voy., Ois._ p. 285. +Emberizoides macrurus+, _Burm. La-Plata Reise_, ii. p. 485 (Paraná). +Emberizoides sphenurus+, _Scl. et Salv. Nomencl._ p. 33.