Elasmobranchii n. pl. : A subclass of fishes, comprising the sharks, the rays, and the Chimaera. The skeleton is mainly cartilaginous.

Example:


Taxonomy
Elasmobranchii, rays, sharks, subclass, free encyclopedia, fish, skates, Fossil range, cartilaginous fish, underwent, the sharks, search, Late Silurian, Carcharodon carcharias, Kingdom, Phylum, Evolution, Fossilised.

Defination from the web:
Elasmobranchii (pronounced /ɛˌlæzmɵˈbræŋki.aɪ/) is the subclass of cartilaginous fish that includes skates, rays (batoidea), and sharks (selachii) ... Members of the elasmobranchii subclass have no swim bladders, five to seven pairs of gill clefts opening individually to the exterior, rigid ...