554 J. G. Malcolmson, Esq.^ on the Fossils of 



sometimes filled with calcareous concretions. In a few instances, these hollows 

 occur out of the line of fissure, and entirely penetrate the stratum, being con- 

 nected below with horizontal channels of the same kind. On the surface, 

 calc-tufF (Kunkur) is very abundant, often adhering to the strata, or investing 

 fragments of the rock. 



The same appearances are seen near the diamond mines of Chinoor on the Pennar, where the 

 strata are much disturbed, and basaltic pebbles cover the banks. The only explanation which 

 can be offered of the phenomena in both those distant localities is, that the extrication of gaseous 

 fluids and water from below, had taken place in the lines of fissure, and had dissolved a portion of 

 the limestone, which was again deposited in the great accumulation of tuff and conglomerate so 

 remarkable in these places. That they at all indicate the " argillaceous limestone " to be of fresh- 

 water origin, could never be imagined by any who had seen the rock in question, which, wherever 

 it occurs in the south of India, is entirely devoid of fossils*. This supposition is confirmed by the 

 phenomena exhibited at the hot-springs of Urjunah, which rise in the same rock, and where 

 bubbles of carbonic acid are extricated through round holes in the mud covering the bottom of the 

 rivulet, the water of which, being loaded with lime, a calcareous tuff is rapidly deposited. 



A gentle elevation, extending three miles to the east of the village of Zynad, 

 is composed of this limestone, and it rises very gradually towards a small conical 

 summit, composed of coarse vesicular basalt, which has broken through and 

 covered the limestone. A portion of this rock appears to have been displaced 

 in a singular manner. A wall of perfectly vertical stratification, about 3 feet 

 thick, projects nearly as much from the general surface, and consists inter- 

 nally of the same limestone, as that which it appears to cut at right angles, 

 while externally it is singularly irregular and altered, being converted into 

 a beautifully crystalline limestone, with quartz minerals. 



To the north of this place, as far as thePayne-Gunga river, the country is fiat, 

 covered with basaltic soil or rock connected with insulated trap hills, and inter- 

 mixed with jaspers, resembhng those so common near Bangnapilly, and perhaps 

 derived from the argillo-calcareous schists occasionally seen in the water- 

 courses. The pebbles of the Payne-Gunga consist mostly of calcedonies of a 

 reddish colour, and of argillaceous limestone, and they are in many places con- 

 solidated into a conglomerate by the calcareous matter with which all the waters 

 of the district abound. In a layer of this conglomerate, projecting from the 

 alluvial soil of which the bank is composed, numerous recent shells are im- 

 bedded. The limestone, and its incumbent schists, are seen north of the river, 

 and they abound in springs and streams loaded with lime, which is deposited 



* This assertion may, in the progress of knowledge, be found to be erroneous ; but having care- 

 fully looked for fossils during extensive journeys through districts principally composed of this 

 rock, I doubt whether such will be the case. Fossil plants have been reported to be found near 

 Gundycottah ; but these I ascertained to be mere dentritic markings on the surface of the strata. 



