This order includes a series of Infusoria of a very anomalous nature. In Acineta or in Podo-phrya (fig. 34, A), which may be taken as types, the body is provided with a number of radiating filamentous tubes, which are furnished at their extremities with suctorial discs, and are capable both of exsertion and retraction. These retractile tubes both seize the prey and serve as vehicles for the ingestion of food : hence the term "polystome," or many-mouthed, has been proposed for the order by Professor Greene. A nucleus and one or more contractile processes are present, but they possess no cilia in their adult condition, and the body is fixed to some foreign object by a stalk-like extension of the cortical layer.