Pavement or Squamous epithelium.

 Pavement epithelial cells are fine thin placed edge to edge like the particles in a mosaic pattern or the stone of pavement. These cells from the alveoli of the lungs. They are found whenever a very smooth surface is essential as in the lining of the heart (serous membrane), lining of blood vessels and lymphatic. When lining these structures the epithelial covering or lining is called endothelium.