Chamydonella alpestris (Foissner,1979), a small hypostome ciliate. The body is strongly curved dorsally and flattened ventrally as shown in this lateral view. The single round macronucleus is located in the mid-body. There are two contractile vacuoles, one anterior and one posterior. This individual has been consuming diatoms. From freshwater pond near Boise, Idaho. Brightfield illumination.