Māg'ī-lis, n.

n. (Zool.) A genus of gasteropodous mollusks, embracing but a single species (M. antiquus), found in the substance of masses of coral. It has a thin, spiral shell, consisting of four whorls, the last and largest of which terminates in a tube reaching to the surface of the mass of coral in the interior of which it lives. Baird.