Polyborus chimango, _Vieill._ Haliaëtus chimango, _Less._ Chimango, _Azar._ Voyage, vol. iii. p. 35. My specimen was obtained at Maldonado, on the banks of the Plata. In the following short account of the habits of this bird, it must be understood that I have confounded together, the _M. chimango_ and the _M. pezoporus_; but I am certain that almost every remark is applicable to both species. From what has been said under the last head, it may be inferred, that both of these allied birds have comparatively limited ranges, compared with that of the _P. Brasiliensis_. Azara says the Chimango (and he first distinguished this species from the _M. ochrocephalus_, or _M. chimachima_) is rarely found so far north as Paraguay. D’Orbigny saw the Chimango (_M. pezoporus ?_) at Arica in lat. 16°, and I killed the _M. pezoporus_ in the extreme southern point of America, in lat. 55° 30′ south. The Chimango, in La Plata, lives chiefly on carrion, and generally is the last bird of its tribe which leaves the skeleton, and hence it may frequently be seen standing within the ribs of a cow or horse, like a bird in a cage. The Chimango often frequents the sea-coast and the borders of lakes and swamps, where it picks up small fish. It is truly omnivorous, and will eat even bread, when thrown out of a house with other offal. I was also assured that in Chiloe, these birds (probably in this district the _M. pezoporus_) materially injure the potato crops, by stocking up the roots when first planted. In the same island, I saw them following by scores the plough, and feeding on worms and larvæ of insects. I do not believe that they kill, under any circumstances, even small birds or animals. They are more active than the Carranchas, but their flight is heavy; I never saw one soar; they are very tame; are not gregarious; commonly perch on stone walls, and not upon trees. They frequently utter a gentle, shrill scream. 3. MILVAGO LEUCURUS. Falco leucurus, _Forster’s_ Drawings, No. 34. MS. —— Novæ Zelandiæe, _Gm._ —— australis, _Lath._ Circaëtus antarcticus, _Less._