142

FISH AND GAME.

much more highly if made from calcined pearls. Hence
the Placuna fishery, because it furnished inferior pearls
in great abundance, was so ruthlessly prosecuted during
the past half-century that from. an average yearly rental
of £344 paid for fishery rights during the eighteen years
ending 1857, and which was a small sum compared with
former records, the amount dropped steadily till now the
beds are mnon-productive, = Depletion through overfishing
is complete, and there is no hope for the industry without
restocking from another locality. The illustration on the
previous page shows a great heap of empty shells accumulated
during some of the last fisheries held.

Edible Oysters.—An excellent variety of edible rock
oyster is found in some quantity at Bentota, 38 miles to
the south of Colombo, and also at Batticaloa, Kottiyar, and
olsewhere on the east coast. Bentota sends frequent supplies
to Colombo, but partly from their thin condition and
small size, and from some suspicion as to the sanitary
condition of their surroundings, the demand is trivial to
what it might be if by the adoption of simple eunltural
methods a fat, well-conditioned oyster were put upon the
market under an official certificate of being grown under
conditions ensuring freedom from contamination. No
restrictions are at present in force.
The oysters of the east coast attain a larger size.
Batticaloa produces in its great land-locked backwater
individuals of the size and shape of a small plate, while
I have seen elongated ones from the mouth of Tampalakam
bay of 10 inches in length. and others have been noted
a full inch longer.
As with the majority of other edible oysters, the low
salinity of backwaters and estuaries favours development.
In Ceylon many square miles of such waters are available
and offer splendid culture areas suitable for the raising of immenge
 quantities of oysters if properly cultched and stocked.

Chanks (Turbinella pyrum).—The large and massive
shells of this fine gastropod molluse form an important
article of trade in the north of the Island. being annually
exported by the million to Calcutta.
Divers collect the live shells chiefly in the shallower parts
of Palk Bay, which lie between Mannar on the south and
Delft and Jaffna on the north. Fishing is also occasionally
carried on along the north-eastern coast between Point
Pedro and Mullaittiva. Many subfossil shells, esteemed
much inferior in value to the live ones, are also taken