II 



maintain the right to rent out the local chank fishery at the present day ; while we have 

 direct and overwhelming evidence that both the Portuguese and the Dutch, over a 

 period of nearly three centuries, exercised the sole sovereignty over the whole of the 

 pearl fisheries on both sides of the Gulf of Mannar. 



The more probable explanation is that these shells represent the remains of a 

 Portuguese pearl fishery camp located here circa 1500-1570, during the period when 

 the Portuguese, at war with the Nayak, blockaded the Madura Coast and removed the 

 Parawas from Tuticorin and Pinnacoil to settlements in the islands at the head of the 

 Gulf of Mannar. This particular island of Nalla Tanni Tivu would be the natural loca- 

 tion of a camp to serve a fishery off the Indian Coast under such circumstances, as it is 

 the nearest one affording a satisfactory and sufficient fresh-water supply. 



Nalla Tanni Tivu and Uppo Tanni Tivu Pars. — Early on the morning of May 

 13th we left our anchorage off Nalla Tanni Tivu and steamed south 2\ miles to the south- 

 west end of Uppu Tanni Tivu Par, where we cast off the four inspection boats with 

 instructions to row B.N.E. over this bank. Several dives from the ship in five fathoms 

 at this place showed the bottom to be flat rock with a considerable amount of sponge 

 growing upon it. Prom this place we steamed to the eastern edge of Nalla Tanni Tivu 

 Par and there awaited the arrival of the inspection boats. 



The results showechthat the interval of sandy bottom between these Pars as shown 

 in the inspection chart is largely absent ; that the extent of hard bottom is more 

 extensive than is charted, and that special attention should be given to this region at 

 inspections, especially in view of the remains of old shells on the neighbouring 

 island of Nalla Tanni Tivu. The depth of water on TJppu Tanni Tivu Par varies from 

 4J to 6 fathoms, while that on Nalla Tanni Tivu Par ranges from 5i to 7 fathoms, 

 depths rather greater than those recorded on the inspection chart. 



The rock on both Pars varies from an almost pure limestone to a calcareous sand- 

 stone, in the former case brownish yellow in colouring and ringing like iron under a 

 blow ; this I consider the bed rock of the plateau and not a recent calcrete. It is 

 apparently identical with the hard limestone of the Jaffna Peninsula of Ceylon. 



Pew specimens were obtained as the water was too clouded with mud to permit of 

 objects being seen upon the bottom. The divers complained bitterly of the discomfort 

 of these conditions under which they had to examine the bottom by touch alone. 



This excessive turbidity is in itself quite sufficient to entail upon pearl oysters 

 starvation, weakness and eventual death, especially in the case of young and immature 

 ones. A similar condition entailing fatal results I noticed among the younger oysters 

 which I kept in aquarium tanks at Gaile during the south-west monsoon when 

 discoloured turbid water is the prevailing condition in Galle Harbour. 



My coxswains, who have been connected with Ceylon inspections for a very long 

 period, 12 to 19 years, state that while the water becomes discoloured on the Ceylon 

 side after a continuance of heavy weather the extent of turbidity is slight compared 

 with what they have seen on this side during the last two days. 



On the rocky ground of this region the tubes of Eunice tubifex were plentiful 

 together with many sponges and gorgonoids, 



Siplionochalina communis, Axinella donnani, A. tuoulata % Isodictya sp., Sulerites 

 inconsians, &c,, were met with, also Juncella juncea (in quantity) and Gorgonia miniacea, 



Neither chank s nor Pinna were found. 



The sand met with was, as usual on this coast, fine grained and largely calcareous, 

 made up in the main of minutely comminuted shells. The quartz grains present were 

 all extremely minute ; foraminifera w'ere fairly abundant. 



In the afternoon as wind and sea increased rapidly we ran for shelter to the north- 

 east side of Uppu Tanni Tivu. By 4 p.m. a very nasty cross sea got up and with the 

 wind blowing half a gale the ship rolled unpleasantly at her anchorage. Towards sunset 

 a strong land wind set in, the sky over the land murky -red and threatening. 



In the morning (May 14th) the landward side of the vessel, and of the awnings, 

 funnel, stanchions, &c, was covered with a thick coating of impalpable red dust ; the 

 murkiness over the land of the preceding night had been due to dust clouds, which, as 

 they prevail throughout the south-west monsoon on this coast, must therefore form no 

 inconsiderable factor in the production of muddy deposits in the sea. 



