150 CRETACEOUS ROCKS OF S. INDIA. [PaRT II. § 2. 



decrease of sediment) from South to North, This decrease continues 

 rapidly as we follow the group still farther in the same direction, until 

 at length we find, in the Pondicherry area, no further distinction between 

 the three zones so clearly defined in Trichinopoly, but fossils characteris- 

 tic of the highest and lowest of these zones, apparently intermingled in 

 the same bed at the very base of the group. 



