frus·tule /ˈfrʌs(ˌ)ʧu(ə)l, (ˌ)t(j)u(ə)l/ 矽藻的細胞膜
Frus·tule n. Bot. The siliceous shell of a diatom. It is composed of two valves, one overlapping the other, like a pill box and its cover. ◄ ►