Fresh-water Pearls. 79
Archipelago assert that Pearls of a yellowish colour have been taken from the Pearly Nautilus {Nautilus potnpilius), one
of the group of cephalopodous molluscs ; but that they throw them away
as they are considered unlucky, adding that if a man fought with a ring
on, bearing such a Pearl, he would surely be killed. Taking into
consideration however the habits and organization of this wonderful
animal, and remembering the beautiful nacreous lining of its shell, it
may possibly be accepted as a true statement. Indeed, Mr. Haynes, has a
specimen in his possession which he considers an undoubted " Nautilus
Pearl."
Fresh-water Pearls.
As our principal supply of marine Pearls is derived from the Aviculidœ, so our fresh-water Pearls are mainly supplied by the great family of the Unionidee. The
most important Pearl-bearer of this family, and the one which chiefly
concerns us, as being the most productive, is the true European
Pearl-mussel, the Unto margaritifera. The word unto is
borrowed by conchologists, from Pliny, who uses it to designate the
Pearl, because as he tells us no two Pearls were ever found exactly
alike, so that the task of matching a Pearl became one of great
difficulty. Each Pearl is in fact unique {unto).