This hawk was not uncommon on the grassy savannahs and hills in the neighbourhood of the Rio Plata. Mr. Gould remarks “that in size it fully equals the _Circus æruginosus_ of Europe, which it doubtless represents in the countries it inhabits. This species has a remarkable specific character in the lanceolate and conspicuous stripes down its breast.” 2. CIRCUS CINERIUS. _Vieill._ Circus cinerius, _Vieill._ Ency. Meth. Falco histrionicus, _Quoy and Gaim._ Voy. autour du monde, Plate 15. Circus histrionicus, _Vigors_, Zoological Journal, vol. iii. p. 425, note. My specimens were obtained at the Falkland Islands, and at Concepçion in Chile. M. D’Orbigny states that it is a wild bird; but at the Falkland Islands it was, for one of its order, very tame. The same author gives a curious account of its habits: in a different manner from other raptorial birds, when it has killed its prey, it does not fly to a neighbouring tree, but devours it on the spot. It roosts on the ground, either on the top of a sand hillock, or by the bank of a stream: it sometimes walks, instead of hopping, and when doing so, it has some resemblance in general habit to the _Milvago chimango_. It preys on small quadrupeds, molluscous animals, and even insects; and I find in my notes, that I saw one in the Falkland Islands, feeding on the carrion of a dead cow. Although in these respects this _Circus_ manifests some relation in its habits with the _Polyborinæ_, yet it has the elegant and soaring flight, peculiar to its family; and in form it does not depart from the typical structure. Mr. Gould remarks that “we see in this elegant bird as perfect an analogue of the _Circus cyaneus_ of Europe, as in the preceding species of the _Circus æruginosus_.” FAMILY.—STRIGIDÆ. SUB-FAM.—SURNINIÆ. ATHENE CUNICULARIA. _Bonap._ Strix cunicularia, _Mol. Bonap._ Am. Orni. I. 68. pl. 7. f. 2.