18 CRETACEOUS ROClvS OF S. INDIA. [PaRT I. 



Trichinopoly have suffered some slight faulting, but to such an extent 

 only as could affect but little the general surface of the country, all 

 except these oldest are quite undisturbed ; and the oldest rocks of Pondi- 

 cherry "which, judging from their fossil remains, are of even greater age 

 than the oldest which occur in Trichinopoly, (with the exception possibly 

 of the plant beds) lie undisturbed, and unaltered, and are at a scarcely 

 greater angle of inclination than that of the present sea-bottom of the 

 Bay. 



We shall see further that a great portion of the Pay en Ghat has 

 But frequent changes of s^^^ered repeated depressions and re-elevations, and 

 ^®^®^* that from the hills, or the still unsubmerged area 



at their foot, have been derived the materials, which, during the oft- 

 repeated oscillations of the country, have accumulated in the thick beds 

 of conglomerate, sand, and clay, which now occupy the Eastern portion of 

 our area, and entomb in vast numbers the fossil remains of the faunas 

 and floras of several successive periods. 



That part of the Pay en Ghat, which forms especially the subject of 

 Extent of countiy *^® present memoir, comprises portions of the 

 described. district of Tanjore, Trichinopoly, and South Arcot, 



and is included in Sheet 79 of the Indian Atlas Maps, the North and 

 South limits of which sheet are also those of the present Survey. This 

 area extends from the parallel of latitude 12 miles North of Pondicheny 

 to that 4 miles South of Negapatam in Tanjore, and is bounded on the 

 East by the Sea coast, and on the West by two of the Hill groups already 

 mentioned, called respectively the Kalrymullays and the Pucha-mullays ; 

 the former being situated to the North in the Salem district, the latter 

 to the South in that of Trichinopoly. 



These two groups, together with the Shevaroys andTainandamuUays and 



Chitairy Hills on the North and North-west, and 

 Hill groups. T -r. 1 1 fN 1 



the Collamullays and Pythoormuilays on the South- 

 west may be regarded as but portions of one great group separated 



