+Rhynchotus rufescens+, _Burm. La-Plata Reise_, ii. p. 498 (Paraná, Rosario, Tucuman); _Scl. et Salv. Nomencl._ p. 153; _Hudson, P. Z. S._ 1872, p. 546 (Buenos Ayres); _Durnford, Ibis_, 1877, p. 263 (Buenos Ayres); _Barrows, Auk_, 1884, p. 317 (Entrerios); _Withington, Ibis_, 1888, p. 473 (Lomas de Zamora). _Description._--Above cinereous; head, wings, and back crossed by black bars with pale ochraceous edgings; neck reddish; primaries chestnut: beneath pale cinereous, strongly tinged with rufous on the neck and breast; chin white; bill ashy, beneath at base yellowish; feet dark flesh-colour: whole length 14·0 inches, wing 9·5, tail 3·0. _Female_ similar, but larger. _Hab._ South Brazil, Paraguay, and Argentina. This large Tinamou, known to the Argentines as the _Perdiz grande_, or "Great Partridge," is found on the pampas wherever long grasses abound, and extends as far south as the Colorado river, its place being taken in Patagonia by _Calodromas elegans_. It is never met with in woods or thickets, and requires no shelter but the giant grasses, through which it pushes like a Rail. Wherever the country becomes settled and the coarse indigenous grasses are replaced by those of Europe, it quickly disappears, so that it is already extinct over a great portion of the Buenos Ayrean pampas. This species is solitary in its habits, conceals itself very closely in the grass, and flies with the greatest reluctance. I doubt if there is anywhere a bird with such a sounding flight as the Tinamou; the whir of its wings can only be compared to the rattling of a vehicle driven at great speed over a stony road. From the moment it rises until it alights again there is no cessation in the rapid vibration of the wings; but, like a ball thrown by the hand, the bird flies straight away with extraordinary violence until the impelling force is spent, when it slopes gradually towards the earth, the distance it is able to accomplish at a flight being from 800 to 1500 yards. This flight it can repeat when driven up again as many as three times, after which the bird can rise no more. The call of the Large Partridge is heard, in fine weather, at all seasons of the year, especially near sunset, and is uttered while the bird sits concealed in the grass, many individuals answering each other; for although I call it a solitary bird, it being a rare thing to see even two together, many birds are usually found living near each other. The song or call is composed of five or six notes of various length, with a mellow flute-like sound, and so expressive that it is, perhaps, the sweetest bird-music heard on the pampas.