BY FRITZ NOETLIN(;, 31. A., PH.D., ETC 13 



of succession. The last two representing planes of frac- 

 ture, the first the original surface of the parent block. 



It must, however, be understood that these features 

 ai'e generally not as simple as here described ; frequently 

 the external (Indieal) face is considerably changed by strik- 

 ing off small Hakes in order to reduce the thickness of the 

 implement. Equally often the Percussion face has en- 

 tirely disappeared, or is greatly reduced in size by mar- 

 ginal chipping along its external (indieal j edge. This is 

 particularly the case in tero-watta that are carefully worked 

 all round by marginal chipping. It is, however, always 

 possible to locate from the marks of nercussion exhibited on 

 the internal (Pollical) face the position of the Percussion 

 face, and it is very seldom, even in the most highly finished 

 tero'-watta, that net a trace of the Percussion face can be 

 discovered. 



It is, of course, quite feasible to strike cff several ex- 

 ternal flakes of the second ordei from one and the samo 

 parent block, after a good working jolane of percussion had 

 been produced by the detachment of the external flake of 

 the first order. No doubt this has been frequently done, 

 but it is also probable that internal flakes were struck off. 

 Such internal flakes should show a portion of the original 

 crust at the distal end (unless it was removed by subse- 

 'cjuent chipping), besides a percussion plane, which may, 

 however, also have been removed by marginal chipping, ^^is 

 fine knife-like tero-watta figured in my paper, "Notes on 

 1113 Tasmanian Amorpholithes ' (Fig 23, 23a, 23b), most 

 probably represents a flake of this type. 



It will be easily seen how these flakes, which we may 

 call Internal flakes of the second order (Fiir. -^-a), differ from 

 these of the first order. In the latter there is no real 

 Percussion face, the plane ci' percussicn being formed by 

 the original surface of the parent block. Unless removed 

 bv chipping the internal flake of the first order should 

 have a fragment of the original crust adhering at the 

 proximal end, and there may also be some of it at the 

 distal end. The last flake struck off the nucleus from 

 KeniDton is a typical example of an internal flake, of the 

 second order. 



The above characters, distinguishing the different kind 

 of flakes, are summarised in the following table: — 



External (Indieal) 

 Face foniierl Ijy 

 the orim'nal 

 crust of the 

 paient Mock : 

 t. ]'3xternal 

 Flakes. 



'1. External and Internal Face onlj^l External Flakes 

 (>rip;inal crust forms plane of - of 1st order, 

 Percussion. J Fig. 2. 



2. E.xternal, Internal, and Percus-^ External Flakes 

 sion FacH, plane of Percussion |_ of 2nd order, 

 represents a former plane of I Fig. 2a. 



{ fi-aoture. J 



