Periostracum
As periostracum is called an outer organic layer on the shell in molluscs ( mollusks ) and brachiopods ( brachiopods ). This consists of Conchiolin, a tanned and sclerotized by quinones protein mixture. On the periostracum follow 2-4 limestone. The periostracum serves as a protective layer for the underlying layers of the shell, as against acid or drilling predators.
See also: cuticle
Swell
- Dictionary of Biology. Volume 6, page 330 Publisher Herder, Freiburg, 1985, ISBN 3-451-19646-8
- Http://www.lebensmittellexikon.de/sch00440.php
- Anatomy (eddy lots)