138 BUREAU OF AMERICAN ETHNOLOGY [bdll. 52 



tical with those of the corresponding implements of the Argentine 

 collection. 



It is observed that the ancient pebble workers of the Argentine 

 coast rarely aimed to make the ordinary leaf blade from the body 

 of the pebble, as was the usual practice with primitive pebble workers 

 elsewhere in roughing out projectile points and knives. Between 

 Mar del Plata and Bahia Blanca only a single well-finished, pressure- 

 chipped blade of ordinary leaf-shape type, made probably from a 

 large pebble flake (fig. 24, a) was obtained by Doctor Hrdhcka. It 

 may have been designed as an arrowhead, the trimming and notch- 

 ing being incomplete. Another specimen, from Necochea, is slightly 

 worked on both sides apparently by free-hand percussion, but it 

 was probably discarded unfinished on account of the development 

 of a high irregular hump on one face (fig. 24, h). 



A few spikelike forms, closely related to the preceding, made 

 from black pebble flakes, and specialized by rather irregular chipping 

 on both margins of the convex face and remaining flat on the other, 

 occur in the collection (fig. 25). 



The collection of pebble-derived implements contains also an 

 example of the duck-bill scraper made of a flake of brown jasper. It 

 was picked up by Doctor Hrdhcka, at Necochea (fig. 26, a). A second 

 scraper of olive jasper, of related but less typical form, was found by 

 the expedition, at Monte Hermoso (fig. 26, h). 



It would appear from the foregoing examinations and experiments 

 that the pebble workers employed anvil-stones and plain and pitted 

 hammer-stones as well as pressure implements (probably of bone), in 

 the shaping work and that the forms made include four varieties of 

 implements; the teshoa blade either unmodified or sharpened by 

 flaking on one or both margins; the spikelike form with flat under 

 surface and high back; the duck-bill scraper; and the leaf-shaped 

 blade worked on both faces. According to the evidence as interpreted 

 by HrcUicka and Willis, the same people which shaped and used these 

 implements used also the mortars, pestles, mullers, grooved ham- 

 mers, bolas-stones, and pottery, as well as the quartzite implements 

 yet to be described, found on the same sites. 



The use of the dark shore pebbles and the implements made from 

 them, as exemplified by the Hrdlicka-Willis coUection, extended 

 from Mar del Plata to below Viedma, a distance along the coast, as 

 already mentioned, of approximately 400 miles. It ma}^ be observed 

 here that identical archeologic conditions continue along the Argentine 

 coast to the north of Mar del Plata and along the coast of Uruguay. 

 Explorations having been confined in the main to coast localities, 

 the coUection throws but little light on the distribution inland of these 

 artifacts. Plowever, one of the black worked pebbles was collected 

 on the beach of the Laguna de los Padres, about ten miles inland. 



