Fresh-ivater Pearls. 8 1 



greatly inferior to the marine Pearls in value and 

 lustre, yet they have realized prices varying from 

 £l to £ioo. 



It may be mentioned that in Japan, small 

 Pearls are obtained from the fresh-water mussels, 

 known to conchologists under the names o'i Aiiadonta 

 japonica and Cristaria spatiosa; while in China the 

 shell which yields many of the river Pearls has 

 been termed Dipsas plicata. Nacreous concretions, 

 more or less resembling true Pearls, are also 

 occasionally secreted by other fluviatile mollusca. 

 These facts are mentioned to shew that Pearls so 

 far from being obtained from only one or two 

 species, are really of wide occurrence. At the same 

 time, the fact remains, that the finest Pearls, 

 whether fresh-water or marine, are of very limited 

 distribution, being confined to a narrow range of 

 species ; and that the pearly concretions occasionally 

 procured from other sources are fitted not so much 

 for use as personal ornaments as to grace the 

 cabinet of the conchologist. 



The subject of river Pearls will be more fully 

 discussed in a later chapter, where descriptions will 

 be given of the Pearls of Great Britain, Europe 

 and North America. 



