Ciliates
The following micrographs have been kindly supplied by Dr Alan Warren, Department of Zoology, Natural History Museum, London, UK.

Amphileptus sp. (possibly A. carchesii), a gymnostome ciliate feeding on the colonial peritrich Carchesium polypinum. Isolated from the mixed liquor of the activated sludge sewage treatment plant at Thames Water's Mogden STW, Middlesex, UK.

Scyphidia physarum (a peritrich ciliate) attached to the freshwater snail Physa fontinalis. Isolated from the River Crane, Middlesex, UK.
A closeup of Scyphidia physarum (a peritrich ciliate) attached to the freshwater snail Physa fontinalis. Isolated from the River Crane, Middlesex, UK.