2S 



At a time when the southern extremity of India extended further to the south, 

 the pearl hanks on both sides of the Gulf of Mannar 'would have, greater protection 

 from the South-West monsoon than they have at present while the extent of suitable 

 ground would be more extensive. At the present day on the coast of Tinnevelly aud 

 Madura a converse process is in operation, the land slowly gaining upon the sea aloug 

 the "coast line facing the central division of the pearl banks. Two factors are at work — 

 the extension of fringing coral reefs along the coast and the distribution upon the sea 

 bottom of considerable quantities of sand and mud brought down by the rivers 

 Tambrapurni, Taipar, and Vembar. There is also a constant movement of sand north- 

 wards during the prevalence of the South- West monsoon, whereby the depth of the 

 water on this pearl bank plateau may possibly be rendered shallower and gain some 

 extension seawards. 





