54 MADRAS FISHERIES BULLETIN [VOL. XVI, 



as in great relative extent, with the Cheval Par, the bank of largest 

 area and greatest productive importance on the Ceylon side. 



General Remarks. 



The great majority of the pars are marshalled roughly in line 

 parallel with and at a distance of from 7 to 8 miles from land. 

 From Kayalpattanam to Vaippar a second and outer series occurs, 

 lying in rather deeper water. The depth of the inner series is in 

 the main 7 to 8 fathoms, that of the outer 8 to II fathoms. 



The surface of these pars consists of a rock which appears in 

 many instances to be of recent origin, rock formed by the consoli- 

 dation of sand and dead corals in situ. The nature of the rock 

 varies considerably, partaking usually largely of the present 

 character of the circumjacent sand and as the latter on this portion 

 of the Indian coast is made up principally of calcareous grains 

 formed from the comminuted remains of shells and corals, so the 

 calcrete is normally a more or less pure limestone. Occasionally 

 the remains of corals are met with, and here and there the calcrete 

 contains a varying amount of quartz sand. The proportion of 

 quartz in no case is so great as that characterizing the typical 

 quartzose calcrete so common on the Ceylon side. In several locali- 

 ties visited during the inspection, I am, however, of opinion that 

 the exposed rock surfaces are not of contemporary origin, being of 

 limestone too hard and compact to be considered a modern 

 calcrete. Further, where such latter calcrete does occur, it appears 

 to me to form but a comparatively thin crust over the underlying 

 more compact bed-rock of the plateau whereof the density and 

 grain appeal to me as significantly identical with the extremely 

 hard, compact rock forming the core of the Jaffna islands and 

 peninsula in the north of Ceylon, and of the rocky ridge that ends 

 in Manappad Point on the Indian side 



In no place did I see any shelly conglomerate, no rock in which 

 the main constituent could be made out as formed from the accumu- 

 lation of shells of pearl oysters, cockles and the like. 



It is impossible to say with any certainty whether the banks 

 which appear at the present day to be the only banks from which 

 we can reasonably expect to reap an occasional pearl harvest, have 

 always had this character or whether the banks which were pro- 

 ductive centuries ago and anterior to the advent of European 

 control were situated further south. Certain facts and inferences 

 incline me to suspect that the latter was, to some extent at least, 



