fistuliform

from The Collaborative International Dictionary of English v.0.48

Fistuliform \Fis"tu*li*form\ (? or ?), a. [Fistula + -form.]
   Of a fistular form; tubular; pipe-shaped.
   [1913 Webster]

         Stalactite often occurs fistuliform.     --W. Philips.
   [1913 Webster]