A small flatworm (Phylum Platyhelminthes). It is sometimes hard to make a distinction between the single celled Ciliates and the multicellular flatworms because these also bear cilia. Flatworms are generally much larger and have eyespots. Their cilia (the little hairs it uses for locomotion) are so tiny they are hardly visible. Many flatworms have their mouth opening not in front but in the centre of their ventral (belly) side (just visible as a round shape in the centre of the portrayed flatworm).