stratum one of several parallel layers of material arranged one on top of another (such as a layer of tissue or cells in an organism or a layer of sedimentary rock)
cutis,
tegument,
skin an outer surface (usually thin); "the skin of an airplane"
stratum lucidum the layer of epidermis immediately under the stratum corneum in the skin of the palms and soles
stratum granulosum the layer of epidermis just under the stratum corneum or (on the palms and soles) just under the stratum lucidum; contains cells (with visible granules) that die and move to the surface