1835.1 Geological Sketch of the Neilgherries. 435 



gularly applied to the different points of the area, or the mass itself, 

 yielding irregularly in the different situations, gave rise to the inequa- 

 lity of the whole surface of these hills. 



To conclude, therefore, it seems that the granitic rocks, which 

 occupy the highest hills of this group, forced their way, and were 

 heaved up through the hornblende slate, which was in consequence 

 distorted and lifted up, as it is seen in the outskirts of the plateau, 

 and in some of the low situations among the hills themselves, (the 

 valley S. and close to Kotagherry ;) we must also conclude, that the 

 decomposition of the rock forming the red earth, and the detritus, 

 must have happened at a period anterior to the existence of organic 

 bodies; no remains of which have hitherto been found in them. 



Specimens from the Northern Circars. 



The specimens (from No. II. to No. IX,) are from the hillock near 

 Puddapungali ; a place not far from Yornagorium, and about five 

 miles from, and south of, Rajahmundry. 



After traversing the alluvial plains of Ellore, the road passes near 

 a knoll, the rocks of which are very interesting in a geological point 

 of view. 



Before reaching the foot of the little knoll in the plain, and in the 

 nullahs, are seen numerous pieces and blocks of a hard whitish lime- 

 stone, spotted in many places with numerous small black specks. 

 This limestone is compact, the fracture glimmering on account of the 

 many grains of calcspar which enter into its composition. 



In the deep nullahs, in the plain, and at the foot of the hillock 

 along the road, we see a conglomerate sandstone, which appears to be 

 the lowest visible rock in this place. Ascending the gentle slope 

 of the knoll, we come upon many masses of wacke, which is decom- 

 posing in thick concentric layers. Proceeding a little higher we 

 meet with a thick bed of limestone, similar to the pieces scattered 

 about on the plain. 



This limestone abounds with fossil shells, which are clearly and 

 better defined in the upper than in the lower portion of it, where the 

 rock assumes a tufaceous consistence, friable, and almost approach- 

 ing the appearance of tertiary limestone. The shells are very numer- 

 ous in this upper stratum ; almost the whole rock results from their 

 assemblage ; they appear to be chiefly bivalves, with a few univalves. 

 Many of the shells have disappeared, their impressions only remaining ; 

 but the oysters which abound in this stratum are in excellent pre- 

 servation, and easily characterized. 



This stratum of limestone, the basset of which is only visible in 



