THK NULLA M U L L A Y S . 



diamond-bearing rock (quarfczite) lying unconformably 

 on the low quartzite hills, and it was from the debris of 

 this among the gravels that the diamonds were obtained- 

 In some cases the rock appears to have been worked 

 in situ ; but the gravel washings were evidently the 

 favorites, 



Before concluding this sketch of the geology, it may be as 

 well to notice the occurrence of stone implements in the 

 alluvial deposits lying round the bases of the mountains, 

 I have found only one rude and much-weathered implement, 

 of the oval shape, on the elevated ground ; but they are 

 common enough at some points on the plains immediately 

 below. They generally lie scattered about over the sur- 

 face of the ground, or in ploughed fields, and in such 

 cases must have evidently been in a very superficial al- 

 luvium : or else, as is most likely, they are from a very 

 superficial deposit of gravel, the remains of which may be 

 seen here and there in the small spreads of soil and gravel 

 left standing over the general level. The first locality lies 

 immediately north-east of Bolapilly, 16 miles north-west 

 of Cummum, where I found numbers of undoubted weapons 

 in a freshly-ploughed field ; and it was on the low ridge, 

 north-east of this village that I found the worn-specimen 

 mentioned above. Among those from the field was 

 one which shews very distinctly the " cone of percussion," 

 or peculiar surface of fracture common to many of the 

 British and Continental implements, said to have been pro- 

 duced by the original blows given by the manufacturer to 

 the chipped stone, This specimen is also remarkably like 

 the Danish and Esquimaux " Scrapers," figured in Lubbock's 

 ' Prehistoric Times.' 



Again, about 6 miles south of the last locality, in the 

 Aukiveed valley, I found more traces of weapons, and 15 



miles further south-south-west at a point about west-north- 



