||Li*thod"o*mus (?), n. [NL. See Lithodome.] (Zoöl.) A genus of elongated bivalve shells, allied to the mussels, and remarkable for their ability to bore holes for shelter, in solid limestone, shells, etc. Called also Lithophagus.

&fist; These holes are at first very small and shallow, but are enlarged with the growth of the shell, sometimes becoming two or three inches deep and nearly an inch diameter.