Source : Webster's Revised Unabridged Dictionary (1913)

Selachian \Se*la"chi*an\, n. (Zo["o]l.)
   One of the Selachii. See Illustration in Appendix.

Source : WordNet®

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