_The Nacar._--What species of shell-fish is the _Nacar_, said to be found
in some of the islands of the Mediterranean, and off the east coast of
{537} Spain. Is it not the same fish from which what is called
mother-of-pearl is taken? Has not some part of it, the beard or otherwise,
been spun and wove? Is the _Nacar_ the true name, or only local; and, if
so, what is the scientific appellation?