254 CEYLON MARINE BIOLOGICAL REPORTS. 



The next landmark north of Vankali is Talaiinannar Point, on whicli the trees grow thickly and 

 iiitl ivbruptly, gi^'ing a well-defined landniarlc and a useful guide for clearing the north-west extremity of 

 ^'aukali reef, where the point is clearly \isiblc, altiiough distant 12 miles. Talaimannar Point 

 is also a useful bearing, coupled with the southern extremity of Mannar island, which latter from 

 tliis point forms a good mark, di.stinguishahle by tlio abiupt ending of the trees, to fix positions on 

 Anaivilundun and Nadukadu Paars. 



It is proposed to replace the palmyra beacons, i.e., Kutrimalle, Karativu, and Dutch Bay, by 

 masonry obehsks, as the palmyra beacons require frequent attention owing to the attack of white 

 ants, and are therefore expensive in upkeep. Masonry obelisks require little attention, and are more 

 conspicuous than beacons built of palmyra trees. 



5. — Paars and other Rocky Areas. 

 The C'heval Paar, noted as being an area on which more oysters have been fished than tlie whole 

 of the remaining paar ground, has always been carefully watched and examined, as here, if nowhere else, 

 oysters may be looked for. Since the last fishery this ground has been most searchingly examined, in the 

 hope that some portion of the late rich harvest of fishable oysters might stiU remain. These hopes, as 

 is well known, were not realized. 



During the course of this close examination of the rocky area, it became apparent that, although 

 the paar ground \vas charted fairly correctly, several rocky areas slio-mi as separate paars were 

 extensions of the main i^aar. We had also reason to beUeve that the paar ground on the north of the 

 Cheval was more extensive than shown. Consequently, a rectangular form of inspection was adopted 

 in i^lace of the old circular method. Tlie latter form left intervening unexamined spaces between 

 the circles, and was open to great distortion owing to the difficulty the boats had of making a true 

 circular course. 



The rectangular method of inspection means that the whole ground is examined, as each square 

 abuts against the next. A greater area is covered daily, and the prevailing north wind can be utihzed to 

 assist the boats, which work across the wind east and west, starting from the ^yindward or north side, 

 where they are towed by the steam tender, which also picks them up on occasions, when the inspection is 

 fiirished, to leeward of the shij»'s position and tows them back. 



This rectangular method of examining the ground (which, as is well known, is done by skin divers) 

 combines inspection work with survey, for it shows the exact lay of the rrfck and the contour very closely, 

 and has revealed considerable differences in the configuration of the Cheval Paar. 



The Periya Paar, and also the true Vankah, reveal similar difierences, the latter being a much 

 greater area than is shown on the old chart. 



The Cheval Paar is formed of two large areas of rock. The one on the west, known as the West 

 Cheval, is a compact, well-defined, oblong stretch of flat rock, only connected with the East Cheval by 

 a narrow run of rocky gromid on the north. A narrow stretch of sand runs north of the Shoal Buoy 

 Position (mentioned before as being the northern extremity of the Karativu shoal). This stretch of sand 

 carries the same depth of water as the paar ground on each side, and is in no way a shoal. The old 

 horseshoe configuration is consequently not correct. The flat rock carries on it heavy calcrete in the 

 centre, living coral on the north, and coral ddbris to the south. 



The East Cheval has been found to have three extensions, wliich have been named northern 

 extension, north-east extension, and south-east extension of tlie East Cheval. The East Cheval is also 

 largely fonned of flat rock, calcrete, and coral debris, the latter predominating, as shown on the chart 

 furnished. 



The northern extension is formed of heavy calcrete on flat rock, and it thins out north to cora 

 debris, then sand. This extension appears to have been knovra as the old Aripu Paar, although it 

 does not quite coincide with the original charted position of this paar, wliich position was found to be 

 all sand. 



