The simple squamous epithelium is made of a single layer of flat (squamous) cells. The stratified squamous epithelium is made of the same type of flat cells placed in several superimposed layers. The simple squamous epithelium is found in the pulmonary alveoli. The stratified squamous epithelium can be found in the moist mucosae, like the mucosae of the mouth, esophagus and vagina, and it is the epithelium of the skin.