In-dū'si-al, a.

(or in-dū'zhī-al), a. [See infra.] Composed of, or containing, the petrified cases of the larves of certain insects.

Indusial limestone (Geol.), a fresh-water limestone, supposed to be composed of the agglomerated cases of the larves of insects of the genus Phryganea. It is found in Auvergne, France, and belongs to the upper Eocene. Lyell.