I think this layer is Stratum lucidum. This is a thin, clear layer of dead skin cells in the epidermis named for its translucent appearance when viewed using a microscope. It is also readily visible under the light microscope only in areas of thick skin, which are found on the palms of the hands and the soles of the feet.
It is located just above the stratum granulosum and below the stratum corneum.
