Phyllopharyngea

The mouths of Phyllopharyngea are characteristically surrounded by microtubular ribbons, called phyllae. Nematodesmata, rods found in several other classes of ciliates, occur among the subclass Phyllopharyngia, most of which are free-living. In others, the mouth is often modified to form an extensible tentacle, with toxic extrusomes at the tip. These are especially characteristic of the suctoria, which feed upon other ciliates, and are unique among them in having multiple mouths on each cell. They are also found in many rhynchodids which are mostly parasites of bivalves.