anodon

from The Collaborative International Dictionary of English v.0.48

Anodon \An"o*don\, n. [NL., fr. Gr. ? toothless; 'an priv. + ?,
   ?, a tooth.] (Zool.)
   A genus of fresh-water bivalves, having no teeth at the
   hinge. [Written also {{Anodonta}}.]
   [1913 Webster]