[1] : The Collaborative International Dictionary of English v.0.48

elasmobranchii \elas`mobran"chii\, n. pl. nl., fr. gr. ? a
   metal plate + l. branchia a gill. zo"ol.
   a subclass of fishes, comprising the sharks, the rays, and
   the chimaera. the skeleton is mainly cartilaginous.
   1913 webster

[2] : WordNet (r) 2.0

elasmobranchii
     n : sharks; rays; dogfishes; skates syn: subclass
         elasmobranchii, selachii, subclass selachii
see also:
subclass elasmobranchii selachii subclass selachii 

Elasmobranchii >> E Words
Elasmobranchii, definition of term: Elasmobranchii
elasmobranchii_pag1.html