1836.] the Country between Hyderabad and Ndgpur. 11 £ 



spar, having a red clay in the interstices. The specimen (No. R. 5) 

 gives an imperfect idea of the singular appearance of this rock. At 

 Dyegham, two miles further north, and about the same distance south 

 from Chiknee, it is seen dipping to the west of south at a consider- 

 able angle, is much fissured, and is reticulated with beautiful veins of 

 calcareous spar, filling up the vertical interstices, which vary from a 

 line to half an inch in breadth ; they intersect each other in all direc- 

 tions without disturbance, and were evidently formed at one time. 



To the east of this, and of the village of Chiknee, there is a very 

 gentle rise of the country, and concentric basalt and great round trap 

 boulders are seen wherever the soil has been removed. On this are 

 found numerous great blocks of indurated clay, of remarkable hard- 

 ness, and exhibiting all the varieties of that mineral, of flinty slate, of 

 compact schist, and of semi-opal*. Many of these masses are also 

 found imbedded in the basalt ; and on a very careful examination, the 

 inference could not be avoided, that they owed their different appear- 

 ances to the greater or less heat to which they had been exposed. 

 Most of them are full of large and small univalve shells, many of 

 which are of fresh-water genera. Many of the shells are changed 

 into opal, others are covered, or their shape taken and preserved by 

 quartz crystals ; while the shells of a few can be separated unaltered, 

 and effervesce with aids. The spines of the small shells are often 

 insulated in cavities in the rock, and their crystalline surface is often 

 very beautiful, when examined with the microscope. Some vertebrae 

 and the head of a fish were met with ; but from the great toughness of 

 the rock, part only could be broken off, and a portion of the same 

 block was converted into a red flint, with shells changed into opal. A 

 large loose block of a slaty structure was found near this, containing 

 fragments of very large bivalve shells of great thickness, along with, 

 wood converted into a black flint, intersected by fine veins of a light 

 purple opal; and other bivalves which had been crushed together, 

 were found in a flinty state on the upper part of the rising ground. I 

 do not think that I go beyond the limits of correct inference, in sup- 

 posing these shells to have lived in a mud formed from the decompo- 

 sition of the clay-slate found in the neighbourhood, and through which 

 the trap is seen to have burstf. 



* Loose specimens of this rock was seen by Mr. W. Geddes, Surgeon of the 

 Madras European Regiment, in 1829, who directed my attention to ascertain 

 their position. 



f Shells were first found here by Mr. W. Geddes, late of the Madras Medi- 

 eal Establishment. 

 R 2 



