90 REMARKS ON THE 



a portion of a considerable formation which occupied the elevated plain 

 under consideration, and which might extend in a northerly and southerly 

 direction for a considerable distance. In Captain Dangerfield's map, a 

 " granular course limestone" formation is laid down, as running from 

 north to south the whole extent of his map, and passing in the neigh- 

 bourhood of the plain in question. I have not seen any thing of this for- 

 mation, it is not improbable, however, that the rocks just described, may 

 be associated with it. 



From Captain Dangerfield's map, it will be seen, that the communi- 

 cation now sent differs in many respects. In some instances, too, I suspect 

 that we have called the same rock by different names. His sandstones 

 and sandstone slates which he describes as skirting the western boundary 

 of the great formation, may be the same as the rock here described as ferru- 

 ginous quartzose sandstone, and his hornstone may be the stratified quartz 

 so often mentioned in this paper. In some situations in Mewar, which I 

 have visited, he has described as hornstone the same rock which I here 

 call quartz — the very remarkable ravine which he mentions, as occurring 

 at the bund of the Udayasdgar, I have often seen, and the rock which is 

 found there, and which he calls hornstone, is exactly similar to a rock of 

 this part of the district, which I have classed with the stratified quartzes. 

 That it is not hornstone, commonly so called, I have no hesitation in 

 Stating, and I cannot help thinking, that the adoption of such a name 

 might give an incorrect idea of the formation in question, and might lead 

 us to confound it with other formations. Where the quartz rock passes 

 into clay slate, it might, perhaps, be named flinty slate. I prefer, how- 

 ever, retaining the general name of quartz, mentioning when it shall hap- 

 pen to pass into any other of the rocks, as for instance, into gneiss or 

 granite, or mica or clay slates, into all of which in different situations it 

 may be seen to graduate. Indeed, it appears to me, that the very large 



proportion 



