madreporic tubercule

from The Collaborative International Dictionary of English v.0.48

Madreporian \Mad`re*po"ri*an\, Madreporic \Mad`re*po"ric\, a.
   (Zool.)
   Resembling, or pertaining to, the genus {Madrepora}.
   [1913 Webster]

   {Madreporic plate} (Zool.), a perforated plate in
      echinoderms, through which water is admitted to the
      ambulacral tubes; -- called also {madreporic tubercule}.
      [1913 Webster]