"The <em>U. elongata</em> is found in Great Britain, and formerly produced numerous pearly; these were famous even in the time of Julius Caeser. In Ireland and Scotland this species has produced pearly, in modern times, valued at between twenty to four hundred dollars." &mdash; Goodrich, 1859

Unio elongata

"The U. elongata is found in Great Britain, and formerly produced numerous pearly; these were…