We found the coral-billed tinamou not uncommon in the wooded districts. They are essentially birds of the tree-covered regions and are difficult to secure on account of their terrestrial habits, and also owing to the fact that they adhere closely to the densest cover. I have on a number of occasions seen captive specimens, but they seem to not take kindly to the restricted life of a cage or aviary, and spent most of the time dashing wildly about, injuring themselves so seriously that they did not long survive. A number of the birds of this locality are not included in the avifauna of Rosario de Lerma, but belong to the Chaco type, and I recognized some species which were common near Asuncion, Paraguay; among them a large blue jay and a brown-shouldered oriole. Our next station was at Volcan. About the only attractive thing about this place was a great lake almost entirely surrounded by high hills, and teeming with water-fowl. The Quechua boy we had brought from Bolivia was the first to find the lake. He rushed back to us excitedly with the information that there was a large body of water near by with a huge, white duck on it; he had shot at the queer bird, that had a black neck, a number of times but failed to hit it. Fortunate for all of us that his marksmanship was poor! The “duck” was of course a black-necked swan belonging to the owner of the terrain, and its untimely demise would have cost us dearly. There were, however, hundreds of ducks; teals, ruddies, shovellers, and pintails; also, many coots, grebes, and rails. The body of water had an area of over a square mile, and in its edges a tall fringe of cattails grew. Marsh-wrens and military flycatchers haunted these swaying green thickets, and grebes stole silently in and out of their ragged borders. There were many disused nests of coots and ducks; but while making our way through the high, tangled growth we came suddenly upon the nest of a giant grebe (_Fulica gigantica_); it consisted of a huge mass of reed stems, slightly concave on top, and extending about a foot above the water; in it were four pointed, brown eggs, heavily dotted with deep brown and black. This was apparently a second clutch, the first, perhaps, having been destroyed. There were scores of other nests, but all were empty and falling into decay. We spent a busy day tramping about the borders of the hidden lake, watching the flocks of coming and departing ducks and bagging such as we needed--whenever a duck or cormorant plumped into the water Boyle swam out and got it; this was risky work that I did not encourage, as the water was ice cold and many fathoms deep, and the ensnaring under-water growths of reeds and cattail stems formed dense, slimy masses capable of holding a man who might become entangled in them until he became exhausted and drowned.