This is the Common Buzzard of the Plata region. It differs from the species previously described in its greater length of wing, and in the habit of flying near the ground when in search of prey; resembling in this respect a Harrier, only its flight is slower and more loitering. It prefers an open country, but on the pampas, like all large Hawks, it meets with great persecution from the ever-vigilant, fierce-tempered Spur-winged Lapwing. I once saw one of these Buzzards, while being so persecuted, make a conquest which greatly surprised me. It was sailing over the plain, about twenty feet from the surface, harried by several Lapwings, when suddenly, just as one Lapwing swept downwards past it in the usual way, apparently missing the head of the Hawk with its sharp wing-spurs by a hair's breadth, the Buzzard struck at and seized it in its claws and bore it to the ground. The screams of the captive and its fellows quickly brought to the spot a cloud of two or three hundred Lapwings, all hovering and screaming their loudest. I ran to the spot to aid in the rescue, when seeing me coming the Buzzard rose heavily from the ground, still carrying the Plover, and flew away beyond reach. 299. HETEROSPIZIAS MERIDIONALIS (Lath.). (BROWN BUZZARD.) +Urubitinga meridionalis+, _Scl. et Salv. Nomencl._ p. 119; _iid. P. Z. S._ 1869, p. 634 (Buenos Ayres); _Salvin, Ibis_, 1880, p. 362 (Salta). +Heterospizias meridionalis+, _Sharpe, Cat. B._ i. p. 160; _Barrows, Auk_, 1884, p. 109 (Entrerios). +Asturina rutilans+, _Burm. La-Plata Reise_, ii. p. 436 (Tucuman). _Description._--Above slaty grey, passing into ferruginous rufous on the head, and blackish on the lower tail-coverts; wing-feathers chestnut, with narrow transverse black bars and long black ends; tail black, with a broad median white band and white tip: beneath clear ferruginous red, with narrow transverse black bars; bill black, yellow at the base; feet yellowish brown: whole length 20·0 inches, wing 16·5, tail 8·3. _Female_ similar, but larger. _Hab._ South America. This Buzzard inhabits the northern portion of the Argentine Republic, and is also found in the woods and marshes along the Plata basin, ranging south to Buenos Ayres. The wings are larger and the flight slower than in the last species. The plumage is nearly of a uniform dark brown. At Concepcion, in Entrerios, Mr. Barrows tells us it is not unfrequently seen in cold weather. In July 1880, during an almost unprecedented rise of the river, it was quite abundant. The stomach of a gorged female examined contained only young grasshoppers. 300. GERANOAËTUS MELANOLEUCUS (Vieill.). (CHILIAN EAGLE.)