Sentence:  The pretty little <WSD>coquinas</WSD> (genus "Donax", family "Donacidae"), often called butterfly shells or wedge shells, are distributed throughout the world. Perhaps the most noted species is the small "Donax variabilis" Say, so commonly found on the beaches of Florida. <WSD>Coquinas</WSD> live in droves just beneath the surface of the sand. Collecting <WSD>coquinas</WSD> is both a fascinating and tantalizing experience. 
Meaning of the word marked with <WSD> tags:  Any of several small marine clams, of the species (noshow=1), common in United States coastal waters. (from mid 19th c.)