BRAZILIAN ROCK INSCRIPTIONS. ` 141 
About half a mile above the locality where the figures occur, I 
found on the upper surfaces of several masses of sandstone, places 
worn by grinding. Some of these were circular, about a foot in 
diameter, quite shallow, and with a convex prominence in the mid- 
dle showing that a tool, probably a stone axe, had been ground 
with a circular motion. One of these hollows is represented in Pl. 
2, fig. 6. Others were shallow, oval hollows, a foot or more in 
length, made by rubbing the tool backward and forward. I saw 
also a long, narrow, and rather deep groove worn in the same way, 
perhaps in the grinding of arrowheads. These grinding surfaces 
looked to me totally unlike those made in sharpening metal tools. 
It is important to note that on the Tocantins, this is almost the 
only place where sandstones occur. There is a great want of 
sharp sandstones suitable for whetstones or grindstones, not only 
on the Amazonas, but in Brazil generally, as I have already else- 
where remarked. This locality would be likely to be frequented 
by savages for the purpose of grinding and manufacturing stone 
implements. I saw no chips on the spot. It will be borne in mind 
that the locality is swept annually by floods. 
At Jequerapud, a few miles farther down on the same side of 
the river, I found on the rocks the spiral represented on PI. 2, fig. 
3, near which was a conical hole. 
Engraved figures occur elsewhere in Brazil, on the lower part of 
the Rio de Sao Francisco (Williams and Burton), in the Province 
Parahyba (Koster), on the Rio Negro, etc. 
The Serra do Ereré is situated on the northern side of the valley 
of the Amazonas at a distance of fifteen or more miles from the 
main river, but a short distance from the Rio Gurupatuba, a few 
miles west of the Villa de Monte Alegre. It is a narrow, very 1r- 
regular ridge, about 800 feet high, running approximately east 
west, and about four to five miles long. The rock is sandstone m 
very heavy beds inclined to the southeastward. These sandstones 
form a broken line of cliffs running along the western side near the 
top, below which is a very irregular rocky slope. On these walls 
of rock, at and near the western end of the Serra, sometimes near 
their base, sometimes high up in conspicuous situations difficult of 
access, are great numbers of rude characters and figures, for the 
most part in red paint, some isolated, others in groups- Some 
rock surfaces are thickly covered with them, many being s° washed 
by rains and defaced by fires as not to be traced out, others being 
