Paramecium (bursaria) (par-a-mee-see-um) is a very familiar genus of ciliates. They eat bacteria and have the mouth recessed in a buccal cavity which lies to the right of the macronucleus. There are cilia all over the body with a caudal tuft of longer cilia at the back of the body. Usually with a layer of extrusomes (trichocysts) under the cell surface and a large oval macronucleus. Contractile vacuoles star-shaped. This species is P. bursaria, a species with symbiotic green algae living inside. The macronucleus has a single spindle-shaped micronucleus located just above it. Phase contrast.