greatly inferior to the marine Pearls in value and lustre, yet they have realized prices varying from £3 to £100.
It
may be "mentioned that in Japan, small Pearls are obtained from the
fresh-water mussels, known to conchologists under the names of Αnadonta 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.
