pentremites

from The Collaborative International Dictionary of English v.0.48

Pentremites \Pen`tre*mi"tes\, n. [NL., from Gr. ? five + L.
   remus an oar.] (Zool.)
   A genus of crinoids belonging to the Blastoidea. They have
   five petal-like ambulacra.
   [1913 Webster]