Source : Webster's Revised Unabridged Dictionary (1913)

Phragmocone \Phrag"mo*cone\, n. [Gr. ?, ?, a fence, an inclosure
   + ? a cone.] (Zo["o]l.)
   The thin chambered shell attached to the anterior end of a
   belemnite. [Written also {phragmacone}.]

Source : WordNet®

phragmocone
     n : the thin conical chambered internal shell (either straight
         or curved) of a belemnite [syn: {phragmacone}]