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DESCRIPTION OF THE PEARL-OYSTER BANKS 

 OF THE GULF OF MANAAR. 



The following account of the physical and biological characteristics of the various 

 "paars" on the Ceylon side of the Gulf of Manaar is drawn up partly from the 

 information obtained by dredging over the ground from the ss. "Lady Havelock," 

 partly from our lines of dives from the " Serendib " during the inspection of March, 

 1902, and partly from the additional information which Mr. Hornell obtained during 

 the fishery of 1903. On this last occasion a European diving dress was available for 

 use which we had not had in 1902 and consequently Mr. Hornell was enabled to 

 descend himself, and so corroborate, correct, and supplement the information derived 

 from the natives* by many further details. The lists of animals found on the 

 " paars " given here are not intended to be exhaustive, or even full. The object is 

 merely to mention a few of the more characteristic organisms in each case. 



The paars may be arranged in two groups, the Northern from Adam's Bridge down 

 to Kodramallai, and the Southern from that point onwards ; we give a chart (tig. 28 

 and fig. 37) of each group. The Northern is by far the more important; it contains 

 more paars, they are of larger extent, and have produced most of the recorded 

 fisheries. The pearl-bank plateau, bounded for the most part by the 10 or 12-fathom 

 line, widens greatly in the northern part of the Gulf of Manaar as it approaches 

 Adam's Bridge (see fig. 1, p. 19); for whereas off Negombo and Chilaw it is only 

 3 to 6 miles from shore, off Aripu and Kondatchi it is from 16 to 20 miles. 



This widening of the plateau north of Kodramallai allows the northern paars to 

 form several series, one outside another, and roughly parallel with the coast, the inner 

 series being about 4 and the outer 18 miles from land. Outside the paars the 

 ground shelves away rapidly to 20 or 30 fathoms, which marks the top of the steep 

 slope down to the mud-floored abyss forming the central portion of the Gulf. Along 

 the line of this slope soundings in some places jump in very short distances from 

 20 fathoms to anything between 100 and 1000, with, of course, interesting differences 

 in the fauna. Within the 10 or 12-fathom line, on the other hand, the ground is for 

 the most part very level, especially on the wider northern part of the plateau. At 

 the Cheval Paar a distance of 12 miles is run from shore before a depth of 7 fathoms 

 is reached a gradient of 1 in 1700. The surface of this plateau is for the most part 



* Mr. Hornei.l, writing to me of the results of his inspection, says that he finds the diagrams compiled 

 from the divers' reports erroneous, and adds, " On the other hand, the results obtained by dredging 

 which sometimes clashed with the divers' reports were proved to be reliable, and indeed wholly 

 accurate. The conclusions based upon this source of information require no emendation merely 

 amplification." 



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