GEOLOGICAL SURVEY OF INDIA. 261 



the region appears in the " Memoirs," Vol. XX., Part 1 . The districts 

 both form part of the tract lying between the water-parting along 

 the axis of the Southern Chats and the Bay of Bengal. Along the 

 sea-board there runs a belt of sedimentary rocks, and westward a 

 great band of crystalline rocks, whil9 the greater part of the low 

 country occupied by gneissic rocks in South Madura and North 

 Tinnevelly is covered with a widespread deposit of regur or black 

 cotton soil. Along the coast from Cape Comorin to the Paumben 

 channel a series of marine rocks, generally calcareous grits, forms a 

 narrow and broken fringe. This formation was once widely 

 extended, but has been removed by denudation, while the outliers 

 and patches of beds which have been left testify to the fact that 

 since their formation under the sea the country must have under- 

 gone an elevation of close upon 200 feet, if not more. There is 

 evidence of a somewhat similar phenomenon in an upheaved coral 

 reef on the northern coast of Rameswaram island, between India and 

 Ceylon ; and the same cause, in Mr. Foote's opinion, upraised both 

 the island and the mainland. It is difficult to resist the inference 

 that the same upheaval led to the formation of what is known to 

 the Hindus as Rama's bridge, and to Mussulmans and Christians as 

 Adam's bridge, the long narrow isthmus which once united Ceylon 

 to India ; while to the same action again may be attributed the 

 formation of the long line of islets running parallel with the south 

 coast of Madura. Local history claims that Rameswaram island 

 was once completely joined to the terra firma on both sides, and 

 that both the Paumben strait and the other passages to the eastward 

 were breached by a tremendous storm about 1480 A.D. The action 

 of the waves has broken the barrier into large flat blocks, which so 

 strongly resemble a series of gigantic stepping stones that it is easy 

 to fall in with the imagination of the author of the Ramayana, 

 which ascribed artificial construction to the bridge.* 



The two great groups into which the soils of Tinnevelly and 

 Madura are divisible are the red and the black, the former being 



* According to the famous old Hindu epic, the construction of the bridge was due 

 to the industry of the great army of monkeys and bears led by Rama and his long-tailed 

 friends, Sugriva and Hanuman, when they proceeded to invade Lanka (Ceyion), during 

 the war with Kama, the king of demons and the abductor of Sitn, Rama's wife. 

 The engineering part of the undertaking was specially entrusted to the monkey Nr.la, 

 a sou of Viwakarma, the famous architect. Perhaps the upheaval of Rama's bridge 

 may have occurred within the semi-mythical time preceding some invasion of the 

 heretical Buddhist kingdom of Lanka (Ceylon) by tho Brahmanical Aryans of the 

 mainland and their LVavidian allies. 



