Source : Webster's Revised Unabridged Dictionary (1913)

Indusial \In*du"sial\, a. [See {Indusium}.]
   Of, pertaining to, or containing, the petrified cases of the
   larv[ae] of certain insects.

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