84 PEARLS [CH. 



Alexander and referred to by Pliny. By some, these 

 fisheries are supposed to be the most valuable in 

 the world and Seurat states that their revenue is 

 estimated to be 10 million francs annually. 



The pearl oysters that are fished are the species 

 Margariti/era vulgaris (the Ceylon Pearl Oyster) 

 and a variety of Margaritifera margariti/era (jyer- 

 sica). The latter is shipped as Bombay shell. The 

 pearl oysters occur all along the coast of Arabia, but 

 the banks (like the i)aars of Ceylon) where the 

 fishing takes place, are situated near the island of 

 Bahrein. The centre of the industry is perhaps 

 Lingali, and the pearls are sometimes known as 

 Lingah pearls, though the term " Bombay pearls " is 

 quite as frequently given to them. The former ap- 

 pellation refers to the place of origin and the latter 

 to the seaport from which they are shipped. Several 

 thousand boats are employed in the fishery but they 

 are usually smaller than the Ceylon boats and the 

 crew averages less than a dozen. The method of 

 fishing is exactly the same as that practised by the 

 Arab divers at Ceylon. 



The diver uses the same small basket of cocoanut 

 fibre, to which one line is attached, for the oysters. 



There is also a line with a heavy stone at the end 

 of it. The diver sinks rapidly by entering the water 

 in a vertical position with one foot in the loop of the 

 rope at its point of attachment to the stone. 



