Figure 3. Scraper Types
One specimen appears to have served a dual function as a tool. A portion of one edge is concave and the remainder convex, as on a typical side scraper. Both working margins display considerable wear.
Examples illustrated by Rogers (1939, pl. 8, h, k) for the desert Playa industry differ in that they are consistently subrectangular, elongated, and have a broader concave scraping edge along each of two sides.
Thumbnail scrapers (fig. 3, b).—Only a single specimen falls in this category. It is roughly circular in outline, thin, lenticular in cross section, and flaked on both surfaces. The example made of a dark-brown chert is 2 cm. in diameter and 4 mm. thick. The lone occurrence of this type of tool would seem to indicate a lack of emphasis on light delicate work. Implements of this nature are usually best associated with cultures of later origin.
Choppers
Unifaced choppers or heavy duty scrapers.—These are produced from large cores of basalt or from a split cobble and exhibit flaking only on one face. (Treganza and Malamud, 1950, pl. 20, d-e).
Bifaced choppers.—These are large cores bifacially flaked along an edge to effect a sharp, sinuous margin that may extend around the entire periphery or only a portion of it (ibid., pl. 20, a-b).
Crescentic Stone or “Amulet”
This class is represented by but a half of a single specimen obtained during the second season (pl. 21, m). Though this specimen varies somewhat from illustrated examples there seems to be little doubt as to its general classification. The function of these implements remains open to question, and varient forms appear to have considerable latitude in time and areal distribution in western United States. Similar forms may be noted for the Lake Mohave Culture and the San Dieguito-Playa industry (Campbell et al., 1937. pl. XXXVIII, a-c; M. J. Rogers, 1939, pl. 8, a-c).
Drill or Reamer