balanoglossus

from The Collaborative International Dictionary of English v.0.48

Balanoglossus \Bal`a*no*glos"sus\, n. [NL., fr. Gr. ba`lanos
   acorn + glw^ssa tongue.] (Zool.)
   A peculiar marine worm. See {Enteropneusta}, and {Tornaria}.
   [1913 Webster]