The Collaborative International Dictionary of English v.0.48:

Cestraciont \Ces*tra"ci*ont\, n. [Gr. ? a kind of fish.] (Zool.)
   A shark of the genus Cestracion, and of related genera. The
   posterior teeth form a pavement of bony plates for crushing
   shellfish. Most of the species are extinct. The Port Jackson
   shark and a similar one found in California are living
   examples.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Cestraciont \Ces*tra"ci*ont\, a. (Zool.)
   Pertaining to, or characteristic of, the genus Cestracion.
   [1913 Webster]