AND, ANIMAL, AQUATIC, BRANCH, CILIATE, CILIOPHORA, DARK, DARKFIELD, FIELD, HETEROTRICHEA, LARGEST, LIGHT, LM, MICROBE, MICROBIOLOGY, MICROGRAPH, MICROORGANISM, MICROSCOPIC, MICROSCOPY, ONE-CELLED, ORGANISM, PROTIST, PROTISTA, PROTOZOA, PROTOZOAN, SINGLE-CELLED, SP, SPIROSTOMIDAE, SPIROSTOMUM, THE, TOM, UNICELLULAR,