Ostracoin quadricorne

from The Collaborative International Dictionary of English v.0.48

Cowfish \Cow"fish`\ (kou"f[i^]sh`), n. (Zool.)
   (a) The grampus.
   (b) A California dolphin ({Tursiops Gillii}).
   (c) A marine plectognath fish ({Ostracoin quadricorne}, and
       allied species), having two projections, like horns, in
       front; -- called also {cuckold}, {coffer fish},
       {trunkfish}.
       [1913 Webster]