10 



It is often difficult to keep groups C-b and C.c separ- 

 ate from the more lamelliform instruments of group D., 

 and it is almost impossible to distinguish the more elab-or- 

 ately worked implements of Cc/2, and those of group Ea. 

 Likewise the three groups pass into those of group F. 



D. LAMELLIFOKM IMPLEMENTS. 



These are flakes properly speaking, and they are ais- 

 ting'Uished from the former by their small thickness, and 

 being struck off from a large piece of rock, they naturally 

 show a well marked Pollical face. They are distinguished 

 from group B.b. by the natural crust being removed by 

 working. 



a. Specimens of very irregular shape, without any 



traces of use, or chipping- These are evi- 

 dently rejects- 



b. The same as the former, but the edges show 



traces of use. 



c. Like the formei;, but the Indical face is roughly 



flaked, aaid the edges trimmed and used. 



d. Semicircular flakes. The convex edge is gene- 



rally nicely trimmed. 



e. More or less oval or quadrangular flakes, whose 



Indical side is well worked with trimmed 

 edges. 



f. Like the former, but of more discoidal forjn- 



E. CHOPPERS. 



Under these names I include all those implements of 

 considerable thickness in which the length does not much 

 exceed the breadth, with a well-developed Pollical, and a 

 more or less elaborately wrought Indical face- The edges 

 are mostly neatly trimmed. This group comprises the most 

 highly finished Archfeolithes, and, as it is naturally a large 

 one, a number of sub-groups can be distinguished. If the 

 tliickness becomes small, it is often impossible to distin- 

 guish it from the former group, or if the Indical face is 

 not much wrought from group Cd. 



a. Specimens of somewhat iiTegular shape. 



b. Specimens of circular shape ; when these speci- 



mens are rather thin it is impossible to keep 

 them separate from D.f. 



c. Specimens of oval shape. According to thickness 



this group passes either into De., Eg., or Fg. 



d. Specimens of more or less quadrangular shape. 



