rotifera

‖n.; pl. [ NL., from L. rota &unr_; wheel + ferre to bear. ] (Zool.) An order of minute worms which usually have one or two groups of vibrating cilia on the head, which, when in motion, often give an appearance of rapidly revolving wheels. The species are very numerous in fresh waters, and are very diversified in form and habits. [ 1913 Webster ]