Howard, G. S. (1979). Atlas of epidermal plant fragments ingested by grazing animals. [Washington]: Dept. of Agriculture, Science and Education Administration : for sale by the Supt. of Docs., U.S. Govt. Print. Off. Four pictures each of epidermal tissue fragments of 2 species of sedges, 30 species of grasses, and 38 species of forbs are shown in an atlas. All the species are used as forages in the Great Plains region of the United States. The atlas is used as a pictorial key for the microhistological identification of plant species in animal diets. The microphotographs are taken at the same scale to facilitate relative size comparisons. A discussion of the identification technique and use of the key is given. KEYWORDS: microhistological technique; diet identification; pictorial key; atlas key; and forage species.