Mot ker-of -Pearl and its Uses. 387 



according to the state of the sea. The finest are met with 

 on sandy bottoms and in the currents. The fishery is 

 extensively prosecuted in the archipelago of the islands of 

 Pomotou and Gambier, and the shells are chiefly taken to 

 Tahiti, where they form a principal article of export, 

 averaging about 1000 tons a year. The shells from the 

 Pacific are fine, thick, and of a silvery white. The fishery 

 about the Gambier Islands is carried on from January to 

 April. One of the neighbouring islands — Crescent Island — 

 furnishes a smaller oyster of straw-coloured hue. 



The export of mother-of-pearl shells from Tahiti varies 

 greatly. In 1845 324 tons were shipped. It then dropped 

 to an average of about 200 tons up to 1852. In 1853 as 

 much as 600 tons were shipped. The exports then fell off 

 to almost none, but in 1868, owing to an increased demand, 

 rose to 420 tons. In 1873 the shipments were 328 tons, 

 and in 1874 410 tons, valued at 20,530. An export duty 

 of \2s. per ton has been imposed since January i, 

 1875, in order to check the taking of undersized shells of 

 comparatively small value from the pearl oyster banks. 



Besides the above shells, 296 tons of what are called 

 Maara shells {Tiu'bo 7nargaritaceiis), valued at ^1480, were 

 shipped from Tahiti in 1874. 



Mother-of-pearl shell to the value of ^600, and pearls 

 valued at 1600, were shipped from the Navigator's Islands 

 in 1858. 



In the Paomotus Islands, mother-of-pearl shell was in 

 1873 only worth twopence to threepence per pound ; in 

 the following year the price advanced to sixpence per 

 pound. 



The pearl oyster of the Pacific is an inhabitant of 

 the interior lagoons of certain of the great coral atolls. 

 The necessities of its existence appear to be clean, grow- 



