2 OEOLOOY OF TRTCHINOPOLY, &C. [ClfAP. I. 



and includes also a part of the southern end of the Baramahal 

 terrace.* 



Politically, the area under consideration includes parts of the fol- 

 lowing districts, Salem, Coimbatore, Trichinopoly, Tanjore, and South 

 Arcot, with a few villages belonging to the Madura Collectorate, and 

 the whole of the French territories of Pondicherry and Carical. 



The Hydrology of this part of South India is very simple, all 



the surface being drained into the Bay of Ben- 

 Drainage systems. 



gal, and chiefly through four principal rivers ; 1st, 



the Cauvery, the lower and middle portions of whose course receive 



affluents from this area, all the southern and western parts of which 



it drains; 2ndly, the Vellaur (the White River), which rises in the 



Tainandamullay range north-east of Salem, and receives the drainage 



of the northern end of the KolymuUays, the northern and eastern 



sides of the Patchamullay range, and of the southern and eastern 



sides of the Kalroyenmullay ; 3rdly, the Punniar, which receives the 



drainage of the northern part, including the northern ends of the 



Shevaroy, Tainandamullay, and Kalroyen mountain ranges ; and 4thly, 



the Ariankup river, which falls into the sea at Pondicherry, and is 



known also as the Gingee river. 



The principal mountain ranges, several of 

 Orography. 



which have already been mentioned, are six in 

 number. 

 1st. — The Darmahpoor Mountains, which lie in the extreme north- 

 east corner of the area to be described. 



2ndly, — The ShervaroyenmiiUay , (anglicised into Shevaroys,) lying 

 south-east of the former range and north of the town of Salem. 



* The descent from the Mysore table-land to the true low country of the Payen 

 Ghat is no where quite sudden, being broken by the presence of an intermediate ter- 

 race of high ground, which either falls away regularly to the seaward, or else, as in 

 great part of the Baramahal, is closed in by ranges of lofty hills or mountains, enclosing 

 thus an elevated area of great dimensions. 



! 224 ) 



