Paramecium

noun

(Gr. paramekęs: long, oblong) A genus of microscopic single-celled organisms (protozoa), sometimes called slipper animalcules, found in fresh water. They are slipper-shaped, 0.1 to 0.3 mm long, and covered with cilia, which are used for swimming and to waft bacteria and small protozoans into the gullet. They reproduce asexually by binary fission and sexually by conjugation. Phylum: Ciliophora.