Sphaerium
noun
Sphae·ri·um
ˈsfirēəm
: a widely distributed genus (the type of the family Sphaeriidae) of small viviparous freshwater bivalve mollusks that have a thin light-colored shell and the siphons separate see fingernail clam
Word History
Etymology
New Latin, from Greek sphairion, diminutive of sphaira ball, sphere