Can any reader identify this protozoa from the rough sketch? It was plentiful in a sample sent to me from Scotland by Alastair Bruce.

It is colourless with a very flexible pellicle, it has a flagellum (I could only see one) which I estimate to be about half the length of the body and which it waves vigorously all the time so impossible to measure. No eye spot was seen. The body is about 60 µm long.

Many were very active, a bulb formed at one end full of granules (fig. a), this changed shape (fig. b) and this shape moved smoothly up to the other end (the mouth?) when a small protrusion formed at the lower end (fig. c). Then the upper shape collapsed and all the granules flowed swiftly down the tube without altering its shape until it reached the lower end when a bulb formed (fig. a). The cycle was then repeated. A few were swimming as at (fig. d) not showing the activity described.

      William (Bill) Ells.

      All comments to the author Bill Ells are welcomed.