This fine Grebe is said by Buffon to be from Cayenne, but we have never seen specimens from anywhere so far north. It was not obtained in Brazil by Natterer or Burmeister, but Azara met with it in Paraguay. This Grebe is called in the vernacular _Macás cornudo_--the first word being the Indian generic name for the Grebes, while _cornudo_ signifies horned, from the bird's habit of erecting, when excited, the feathers of the nape in the form of a horn. The species is found throughout Eastern Argentina, from its northern limits to Central Patagonia, where Durnford found it common and resident. On the Rio Negro I found it abundant, and it was formerly just as common along the Plata river, but owing to its large size and the great beauty of its lustrous under plumage it is very much sought after and is becoming rare. It is impossible to make this Grebe leave the water, and when discovered in a small pool it may be pursued until exhausted and caught with the hand; yet it must occasionally perform long journeys on the wing when passing from one isolated lake to another. Probably its journeys are performed by night. There is little diversity in the habits of Grebes, and only once have I seen one of these birds acting in a manner which seemed very unusual. This Grebe was swimming about and disporting itself in a deep narrow pool, and showed no alarm at my presence, though I sat on the margin within twenty-five yards of it. I saw it dive and come up with a small fish about three inches long in its beak; after sitting motionless for a little while, it tossed the fish away to a considerable distance with a sudden jerk of its beak, and then at the instant the fish touched the water it dived again. Presently it emerged with the same fish, but only to fling it away and dive as before; and in this way it released and recaptured it about fifteen times, and then, tired of play, dropped it and let it escape. Mr. Gibson has the following note on the breeding-habits of the Great Grebe, as observed at Ajo, near the mouth of Rio de La Plata:--"_P. major_ breeds about the end of August, placing its nest in the thickest rushes of the swamp. The nest, built of wet water-weeds, is raised just above the level of the water; and I have twice seen the sitting bird hastily draw some weeds over the eggs before leaving them, on my approach. The clutch consists of three; and these are of the usual Grebe colour, generally much soiled and stained. They average 2-6/40 × 1-7/40, the length sometimes presenting a variation of 9/40, even in eggs of the same nest." 420. PODICEPS CALIPARÆUS, Less. (BRIGHT-CHEEKED GREBE.) +Podiceps caliparæus+, _Darwin, Zool. Voy. 'Beagle,'_ iii. p. 136; _Scl. et Salv. Nomencl._ p. 150; _iid. Ex. Orn._ p. 190; _Durnford, Ibis_, 1877, p. 45 (Chupat), et 1878, p. 405 (Centr. Patagonia); _White, P. Z. S._ 1883, p. 43 (Cordova).