proostracum Meaning, Definition & Usage

Pro*ös"tra*cum noun (Also<

• Proostracum
• Proöstracum

)

Etymology

NL., fr. Gr. before + shell of a testacean.

Wordforms

plural Proöstraca

Definitions

1. (Zoöl.) The anterior prolongation of the guard of the phragmocone of belemnites and allied fossil cephalopods, whether horny or calcareous. See Illust. of Phragmocone.