216 



Notes on Geological Specimens from 



[July 



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 burst*. 



The country to Naugri continues to be composed of basalt, which is 

 in some places tabular, with green earth between the laminae ; and the 

 soil is covered with calcedonies, ribbon and pudding stone, jaspers 5 

 resembling those found in the Nirmul hills, to which the whole cha- 

 racter of the formation remarkably assimilates, and leaves no doubt of 

 their belonging to one great period of protrusive violence. 



At Naugri, fossils like those of Chiknee are formed ; and with the 

 conical masses of calcedony, having a smooth flat base of cachelong, the 

 centre being filled with quartz crystals and calc spar ; which were 

 afterwards seen in situ at Hingan ghat, inserted between the globular 

 basalt with the apex downwards, the peculiar appearance of the base 

 being perhaps caused by slow cooling. 



At Hingan ghat, a number of blocks, loose, of a black and red chert, 

 containing silicified branches of dicotolydonous trees, and a very perfect 

 portion of a palm (date ?) tree were discovered : and the same kind of 

 rock, but without fossils, protruded from the basalt a little below 

 Colonel Lambton's tomb. The basalt was globular, but seems to have 

 had a tendency to form five or six-sided prisms. The rest of the 

 route to Nagpur is over a level counhy, from which a few insulated 

 trap hills rise abruptly, on whose summits basaltic columns are occa- 

 sionally met with. On the south side of the small range of hills near 

 the city, these columns are very regular, and inclined to the south, at 

 an angle of 45° , in consequence of which many of them have fallen. 

 The fiat top of the hill forms a pavement of the ends of similar co- 

 lumns perpendicular to the horizon. The round flat topped hill of 

 Sitabuldee, which is accurately described by VoYSEYin the 18th volume 

 of the As. Rs. is separated a few hundred yards from the extremity of 



* Shells were first found here by Mr. \Y. Gbdbbs, late of the Madras Medical Establish- 

 ment. 



