The outer surface of a piece of flint.
The tissue of a stem or root that lies inward from the epidermis, but exterior to the vascular tissue.
The outer layer of an internal organ or body structure, such as the kidney or the brain.
A thin skin formed on the surface of a liquid.
A noncellular protective covering outside the epidermis of many invertebrates and plants.
The strip of hardened skin at the base and sides of a fingernail or toenail.
The outermost layer of the skin of vertebrates; the epidermis.
Dead or cornified epidermis.