holmes'" 



ABORIGINAL AMERICAN ANTIQUITIES PART I 



211 



of this wall are seen rounded or elliptical concretions of fine-grained 

 chert, many taking the form of chalcedony and agate, materials 

 highly prized by the tribes for the manufacture of projectile points, 

 scrapers, and other small chipped implements (figs. 89, 90). 



In the more open spaces between the pits, especially on the south- 

 ern slope of the eminence, are many round tipi circles manifestly 



Fig. 88. Sketch map of the Wyoming quartzite quarry area, by R. F. (jilder. 



representing recent occupancy of the site. Xo quarry implements 

 except hammerstones were found, and these were merely rough, ir- 

 regular masses of quartzite or nodules of other materials which, on 

 account of their hardness and toughness, were suitable for the pur- 

 pose. Their identification as implements was made possible by the 

 presence of abrasions which could only have come from usage in 



