periostracum

[per-ee-os-truh-kuh m]
noun, plural per·i·os·tra·ca [per-ee-os-truh-kuh] /ˌpɛr iˈɒs trə kə/.
  1. the external, chitinlike covering of the shell of certain mollusks that protects the limy portion from acids.

Origin of periostracum

1830–40; < New Latin, equivalent to peri- peri- + ostracum a shell < Greek óstrakon. See oyster
Related formsper·i·os·tra·cal, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for periostracum

Historical Examples of periostracum

  • The periostracum, or epidermis, is heavy and often velvety or even hairy.

    The Sea-beach at Ebb-tide

    Augusta Foote Arnold

  • Gray calls it the Periostracum, from the membranous skin covering the bones of quadrupeds.

    A Conchological Manual

    George Brettingham Sowerby