I've recently been looking at the slender roots that hang down from duckweed. There are quite a few creatures that seem to like this location and call it home. I've seen quite a few of these Platycola. They are a "sessiline peritrich ciliate" that live in a lorica that is attached to the root by it's long axis.
63X objective, 2.5X photo-eyepiece. Canon 10D. Brightfield with electronic flash.