hkdliCka] stone INDUSTEIES OP THE AEGENTINE COAST 117 



It is also highly probable that in exceptional instances a smaller 

 chip or implement, moved by running water, wind, or gravity, is 

 lodged in a hole or a depression where it eventually becomes covered 

 by alluvial or eolic materials. Examples illustrating this were 

 observed on the slopes of the Campo Peralta and will probably be 

 reported from time to time from other localities. Similar agencies 

 may explain the presence, mentioned by Professor Ameghino, of 

 two black stones buried near the carapace of a glyptodon, on the 

 small rloping denuded Punta Porvenir, which is about a mile 

 distant from the Campo Peralta. (See map, fig. 2.) 



In at least two localities worked stones were found on or in the 

 black vegetal surface soil outside of the playas. One of these was 

 the Campo Peralta, just south of Mar del Plata, and the other the 

 north bank of the Rio Quequen, near the mouth of the stream, in the 

 neighborhood of Necochea. 



On the Campo Peralta the writer found several larger anvil-stones 

 in the grass-covered, undenuded and hitherto undisturbed part of 

 the surface. The stones lay more or less buried in the vegetal soil 

 and, barring one or two exceptions, with the pitted surface upward. 

 Some were near and some distant from the denuded part of the playa, 

 on which were found numerous worked stones of all varieties. The 

 difference in level between the sward-covered and more inland part 

 of the playa and the uppermost portions of its denuded surface, rich 

 in flaked stones, chips, etc., was only slight, not more apparently 

 than a few inches. 



Some of the stones observed in situ on the grass-covered black soil 

 were photographed before removal (see pi. 10). When they were 

 lifted, it was seen that the lighter ones were undergrown with grass 

 roots and blanched grass, which made it appear at first sight as if the 

 stones had been placed there recently; but on examination of other, 

 unworked stones on the same surface, and also elsewhere, it was 

 found that grass invariably forms such roots and etiolated stems 

 under stones that are not very heavy or very large or deeply buried. 

 On being shown these anvil-stones in the grass. Professor Ameghino 

 surmised that they had been carried there by boys, ranch hands, or 

 excursionists; but on careful consideration of the case this hypothe- 

 sis, as applied to at least the majority of the specimens, seemed quite 

 improbable. The locality is as yet without settlers. A single family 

 lives in a depression half a mile away, but the children of this family 

 knew nothing of the stones, which are not of a nature to attract ordi- 

 nary curiosity. The place is distant from Mar del Plata and is not 

 near the beach or other places where excursionists are likely to roam. 

 Were it visited at all, it is reasonable to assume that the stone imple- 

 ments on the denuded part of the flat would have been taken or 

 scattered. Furthermore, some of the anvil-stones were too heavy 



