| Urocentrum Nitzsch, 1827 (syn. Calceolus). Single species. |
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| Contents | Classes | Subclasses | Orders | Suborders | Families |
Family UROCENTRIDAE Claparéde & Lachmann, 1858
| Syn. | Calceolidae |
Body short, cylindrical, with two broad encircling bands of closely set cilia plus an eccentric posterior tuft; no depressed prebuccal area, and buccal cavity subequatorial in location; contractile vacuole single, with multiple collecting canals; common planktonic or polysaprobic organisms in fresh-water habitats.
| Urocentrum Nitzsch, 1827 (syn. Calceolus). Single species. |
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