The Collaborative International Dictionary of English v.0.48:

Elasmobranch \E*las"mo*branch\, a. (Zo["o]l.)
   Of or pertaining to the Elasmobranchii. -- n. One of the
   Elasmobranchii.
   [1913 Webster]

WordNet (r) 3.0 (2006):

elasmobranch
    n 1: any of numerous fishes of the class Chondrichthyes
         characterized by a cartilaginous skeleton and placoid
         scales: sharks; rays; skates [syn: elasmobranch,
         selachian]