Source : Webster's Revised Unabridged Dictionary (1913)

Sertularian \Ser`tu*la"ri*an\, n. (Zo["o]l.)
   Any species of Sertularia, or of {Sertularid[ae]}, a family
   of hydroids having branched chitinous stems and simple
   sessile hydrothec[ae]. Also used adjectively.

Source : WordNet®

sertularian
     n : feathery colony of long-branched stems bearing stalkless
         paired polyps