304 BUREAU OF AMERICAN ETHNOLOGY [Bull 177 
Ficure 120.—Stone choppers from habitation sites of the Rupununi Phase. 
Manos.—Five pebbles, 4 of quartzite and 1 of quartz, have one 
surface worn from grinding. All appear to have been circular or 
slightly ovoid, 8.0 to 9.5 em. in maximum diameter and 3.1 to 4.5 
em. thick. Three have wear on only one face, the other two on both. 
Metates—Fragments of 3 metates, one each of syenite, granite, and 
quartzite, are identified by a slightly concave, worn surface on one 
side. They are broken from larger slabs 3.5 to 4.7 cm, thick. One 
fragment from near the edge shows a marked indention where the 
concave surface is set off from the border. The small’ size of the 
pieces makes reconstruction of the original dimensions impossible. 
Shaft polisher (pl. 68, ¢)—A considerable number of potsherds 
were found with grooves on one or both surfaces, worn by abrasion. 
One quartzite pebble bears similar grooves. The pebble is 5.3 by 4.5 
cm., and 2 em. thick. A straight groove has been worn across each 
surface, one 10 mm. wide and 7 to 10 mm. deep, the other 8 to 9 mm. 
wide and 7 to8 mm. deep. The latter surface also has a short depres- 
sion 6 mm. wide and 1 mm. deep with a pointed end, running at right 
angles to the main groove. : 
Cores and flakes——Two small cores and a number of percussion 
flakes were collected at various sites. They show little or no evidence 
of use and are probably either byproducts of the manufacture of 
