*indusial*

a. [ See Indusium. ] Of, pertaining to, or containing, the petrified cases of the larvæ of certain insects. [ 1913 Webster ]

Indusial limestone (Geol.), a fresh-water limestone, largely composed of the agglomerated cases of caddice worms, or larvæ of caddice flies (Phryganea). It is found in Miocene strata of Auvergne, France, and some other localities.