GAWILGERH RANGE OF HILLS. 103 



either to the genus conus or voluta. It is not possible to conceive that so 

 fragile a substance as a thin land shell, should have been so completely 

 flattened without fracture, unless it had been previously softened by 

 some mode, which at the same time produced a sufficient degree of pres- 

 sure to effect its flattening. 



I have attempted, in the annexed sketch, to give a representation of 

 the degree of flattening ; but I fear that it can only be well understood by 

 the specimens themselves. Neither the rock nor its contained shells, 

 effervesce in acids. Westward, the ground is covered by the debris of a 

 shelly conglomerate, much more indurated and impregnated with green 

 earth, exhibiting cavities and shells in relief: from the shape of the 

 former, there can be no doubt of their having once contained shells. 

 Some of the shells are entire, but are rarely flattened. The matrix 

 appears to be siliceous, and, in some cases, approaches to imperfect helio- 

 trope. It is not fusible before the blowpipe. 



I may here mention that, in a report to the Marquis of Hastings, in 

 June, 1819, 1 mentioned the existence of shells in trap rocks at Medconda, 

 at a height of two thousand feet above the sea. The hill was composed 

 of nodular-trap, and lying on its surface, were numerous pieces of siliceous 

 stone, containing shells of the genera turbo and cyclostoma — the specific 

 gravity of the stone varied from 2-0 to 2-5 : the shells did not effer- 

 vesce in acids, although some of them preserved their external polish. 

 Internally, some of the stones appeared to pass into flint, particularly 

 those of small specific gravity, whilst their external surface effer- 

 vesced in acids. Some of the small shells were completely changed 

 INTO cALCEDONY. Spccimeus of tlicse shells are lodged with the Asiatic 

 Society. 



It 



