periostracum 的定义
plural per·i·os·tra·ca [per-ee-os-truh-kuh]. /ˌpɛr iˈɒs trə kə/.
- the external, chitinlike covering of the shell of certain mollusks that protects the limy portion from acids.
更多periostracum例句
- Gray calls it the Periostracum, from the membranous skin covering the bones of quadrupeds.
- The periostracum, or epidermis, is heavy and often velvety or even hairy.