chap. xi. of Recent Origin. 359 



small rocky islets, — as must have been the case, if the 

 high tosca-plain round the Ventana and adjoining 

 Sierras, had not been already uplifted and converted 

 into land, supporting mammiferous animals. At Punta 

 Alta we have good evidence that the gravel-strata, 

 which certainly belong to the true Pampean period, 

 were accumulated after the elevation in that neighbour- 

 hood of the main part of the Pampean deposit, whence 

 the rounded masses of tosca-rock were derived, and 

 that rolled fragment of black bone in the same peculiar 

 condition with the remains at Monte Hermoso. 



The number of the mammiferous remains embedded 

 in the Pampas is, as I have remarked, wonderful; it 

 should be borne in mind that they have almost exclu- 

 sively been found in the cliffs and steep banks of rivers, 

 and that, until lately, they excited no attention amongst 

 the inhabitants ; I am firmly convinced that a deep 

 trench could not be cut in any line across the Pampas, 

 without intersecting the remains of some quadruped. 

 It is difficult to form an opinion in what part of the 

 Pampas they are most numerous ; in a limited spot 

 they could not well have been more numerous than 

 they were at P. Alta ; the number, however, lately found 

 by Seiior F. Muniz, near Luzan, in a central spot in 

 the Pampas, is extraordinarily great : at the end of 

 this chapter I will give a list of all the localities at 

 which I have heard of remains having been discovered. 

 Very frequently the remains consist of almost perfect 

 skeletons; but there are, also, numerous single bones, 

 as for instance at St. Fe. Their state of preservation 

 varies much, even when embedded near each other : I 

 saw none others so perfectly preserved as the heads of 

 the Toxodon aud Mylodon from the white soft earthy 

 bed on the Sarandis in Banda Oriental. It is remarkable 



