114 MADRAS FISHERIES BULLETIN [VOL. XVI, 



extremity of the Manappad group of pars. No information is given 

 in the inspection summary of the character of the bottom. It would 

 be advisable if the Inspector be instructed to pay special attention to 

 this group during the next few inspections in order to obtain data 

 for comparison of these banks with the better-known ones of the 

 Central division. 



Historical evidence as already quoted points to some at least of 

 these banks being occasionally productive. I know of no physical 

 reason why such conditions should cease. 



Northern or Kilakarai Division. 



The limits of the banks comprized in this category lie between 

 Vaippar on the south and the island of Ramesvaram on the north, a 

 distance of 60 miles. In the past considerable attention has been 

 devoted to their examination, very much more indeed than that 

 given to those of the Southern division which are more deserving 

 of such care. 



All these northern pars suffer from the excessive turbidity of 

 the sea which prevails during stormy weather. The proportion of 

 mud present in their sand is much greater than in the case of 

 either the Central or the Southern division, and as a consequence 

 pearl oysters exist in a condition of chronic starvation, are stunted 

 from an early period and never survive to a fishable age, if we may 

 judge by the records of the past 100 years and from the effects 

 I have noticed in those experiments where I have kept oysters 

 under circumstances simulating a like condition of silt-laden water. 



Much of this mud is derived from the rivers entering the sea 

 between Vaippar and Pamban, mud which moves north-east up the 

 coast during the south-west monsoon period. In several places 

 eddies caused by the deflection of the current by the presence of 

 the chain of islands lying parallel with this part of the coast 

 conduce to the formation of mud deposits at definite localities, one 

 of which we found between Nallatanni Tivu and Upputanni Tivu 

 Pars ; other mud deposits are marked on the Admiralty chart. 



Between Nallatanni Tivu and Pamban the banks have all the 

 characteristics of the useless Ceylon banks immediately south of 

 Mannar island and are distinguished by an inordinate luxuriance 

 in growth and variety of Algae, such as Laurencia, Polysiphonia, 

 Corallina, Chrysymenia uvaria, tialimida tuna, and Kallymenia 

 perforata. 



