The Occurrence and Distribution of Diamonds in India. 557 
when broken up, it would seem that the latter must include an 
earlier if not the original matrix of the gem. ‘This point is of 
great interest, since it brings us to a horizon, the base of the for- 
mation, which is strictly comparable with that of the Banaganpili 
group, which includes the lowest known matrix in Southern 
India. The order of succession of the rocks in the Mahanadi- 
Godaveri tract has not yet been ascertained ; but from the fact of 
the only known localities where the diamond occurs being situated 
on the margin of the area, it may with a considerable degree 
of probability be assumed (notwithstanding possibly faulted 
boundaries) that the matrix is in a bed close to the base of the 
formation. 
With regard to the minor areas, the Badrachelum diamonds 
may perhaps have been derived from some of the Karnul or 
Vindhyan rocks in the neighbourhood of the Godaveri. 
The geology of the Chutia Nagpur localities is not yet known, 
but it is probable that in their vicinity an outlier of the Mahanadi- 
Godaveri rocks may exist. 
The Simla diamonds, if the find be authentic, are of considerable 
interest, for although, as has been shown, diamonds per se do not 
afford evidence sufficient for exact correlation, still when it is 
remembered that according to some authorities the older Paleozoic 
rocks of the Himalayas present many points of resemblance with 
those of the Peninsula, the possibility of the matrix containing 
these diamonds being on a horizon comparable to that in the 
Banaganpili group of the Karnul (L. Silurian?) formation cannot 
fail to suggest itself. 
As particulars regarding the exact locale whence the diamonds 
were brought is not available, it would be useless to enter further 
here into any account of the geology of the neighbourhood of 
Simla. 
Mr. Griesbach, of the Geological Survey of India, has recently 
published some interesting remarks upon the correlation of the 
Vindhyan rocks of India, with certain series occurring in South 
Africa, to one of which the sandstones of the Table Mountain 
belong. The possibility of the Cape diamonds therefore belonging 
to a period or horizon directly comparable to that which includes 
the Indian diamonds does not fail to suggest itself as a subject 
