Simple squamous epithelium
This type of epithelium is found covering surfaces that are not exposed to much irritation. For example, blood vessels are lined by simple squamous epithelium (which is more specifically called endothelium when it lines a blood vessel). The fluid-filled body cavities (or parts of the coelom) are also lined with simple squamous epithelium, here called mesothelium. This slide is a whole mount of sheet of mesothelium and does not contain other tissues. However, remember that it is not a cross section, so you are looking down on cells.
Observe the tissue at low, mid, and high magnification. At mid magnification the purple-stained nuclei are clearly visible. Not all neuclei are labeled in this image, but can you identify some of them?