556 Scientific Proceedings, Royal Dublin Society. 
substituted, the conclusion is probably in the main correct, and 
borne out by the most recent researches. But these researches 
have demonstrated that the principal diamond-bearing strata of 
the northern and southern areas respectively occupy distinct 
horizons, in those cases where the beds are not merely recent or 
sub-recent accumulations of debris. 
It is due to Captain Newbold to say that he disagreed with 
the conclusions of many of the previous authorities, and he 
appears to have been inclined to regard the ‘sandstones’ as being 
of Devonian age—a supposition probably not very far from the 
truth. 
The Vindhyan rocks of Northern India are separated into two 
formations or sets of groups, distinguished as Upper and Lower. 
In Southern India, and possibly also in the Central Mahanadi- 
Godaveri tract, it is considered that the lower set of groups is 
alone represented, and the two have been correlated, as follows :— 
On the southern rocks the local title of Karnul forma- 
tion has been conferred. 
Norruern Inpra. Mapras. 
Vindhyan Formation. Karnul Formation. 
Bhanrer Group. 
Upper. <~ Rewah » (diamonds). 
Kaimur _,, 
( Tirhowan Limestone 
| Palkoa Shales 
Lower. { Dalchipur Sandstones 
| Semri Shales and Limestone 
{ Semri Sandstone 
Khundair Shales and Limestones. 
Paneum Quartzites. 
Jamalmadgu Shales and Limestone. 
Banaganpili Sandstones (diamonds). 
At Panna, in Bandelkhand, diamonds are only known certainly 
to occur 77 sitwin a conglomerate which is referred to tne Rewah 
group. There are, however, as elsewhere, numerous workings in 
alluvial or superficial deposits; but the greatest amount of labour 
is Spent in mining in this the bottom bed of the group, which, 
though it has a wide extension, has only as yet been ascertained 
to be diamond-bearing in the neighbourhood of Panna. Although 
diamonds have not been obtained directly from any lower group, 
it would appear that this conglomerate is largely made up of 
pebbles derived from the lowest or Semri sandstone group, and since 
it is stated* that diamonds are sometimes found in these pebbles 
* Mr. Medlicott, from whom I quote, states that this needs confirmation. The state- 
ment was made to him by a native miner.-—JJanual, p. 92. 
