66 



BUREAU OF AMERICAN ETHNOLOGY 



[Bull. 1S2 



tliere occurs a burin facet indicating that this flake functioned both 

 as a knife and as a burin. The ventral surface is flat and unworked. 



INTERMEDIATE STONE INDUSTRY 



In the intermediary group not only various types of burins, borers, 

 scrapers, cores, perforators, knives, and projectile points have been 

 identified, but also blades of various sorts. 



Borers are merely large flakes, usually of chert and rarely of rhyo- 

 lite, which were shaped by pressure chipping or percussion chipping 

 into the desired forms that were destined for this purpose. They are 

 roughly triangular in shape, square to subconcave based, and lenticu- 

 lar in cross section across the perforating portion of the tool. 



Burins in this class are much larger than in the microlithic indus- 

 try and are characterized by their various shapes. Some appear to 

 have been carefully fashioned while others are roughly made. Among 

 the identifiable types are angle, bec-de-flute, faceted angle, flat, and 

 polyhedric. On the whole, they are more typical of the tool types 

 than are the microblades (pis. 16-17; fig. 3). 



Angle hurins are comparable to types associated with the upper 

 paleolithic varieties of the Old World and display similar methods of 

 construction displaying tranverse or oblique retouch. 



Bec-de-flute hurins may occur with either single or double working 

 edges, viz, single- faceted or double-faceted types. Some have the 

 working edge slightly twisted. 



FiGDRE 3. — Burin types: a. Ordinary bec-de-flulc; b, single faceted; c, polyhedric; d, parrot 

 beak; e, oblique concave angle; /, flat graver; and g, beaked graver with side notch. 



