Illustrated plate depicting rotifera, microscopic multi-celled organisms living in water. While microscopic in size, rotifera have digestive and vascular systems and are commonly classified according to three features: the ciliary wreath, the mastax, and the foot. Figures A through E are diagrams depicting various forms of the trochal disc at the anterior end of a rotifer's body that serves to draw in food or to propel the animal. Figures F through I diagram the structure of the foot. Figures J through P are diagrams depicting various forms of trophi, also known as the mouth parts or masticating organs.

Figures 1 through 5 depict rotifera in various forms. Figure 1 is magnified at 100 diameters. Figures 2 is magnified at 200 diameters. Figures 3 through 5 are magnified at 150 diameters.