Bible Dictionaries
Frustule

Webster's Dictionary

(n.) The siliceous shell of a diatom. It is composed of two valves, one overlapping the other, like a pill box and its cover.

Bibliography Information
Webster, Noah. Entry for 'Frustule'. Noah Webster's American Dictionary. https://www.studylight.org/​dictionaries/​eng/​web/​f/frustule.html. 1828.