Image 4 (different animal to first 3 pics) to give idea of size - approx 10-15mm. Many of these found under the rocks here at Epple/West Bay.
No interactions present.
There's a good chance you are right Graham. Picture 3 is the best.
I have been revisiting my own Post http://www.ispotnature.org/node/364533 and that of Joyce Scott's here http://www.ispotnature.org/node/453665.
I am beginning to feel that all posts like this, no agreements, no comments, consigned to history deserve some attention.
Andy Cowley's site has a good reference - but no text http://www.joc123.webspace.virginmedia.com/Leptoplana-tremellaris.html
I may well come back again to agree, even though I cannot see its genitals.
THREE MARINE PROJECTS
Lat/Lng: 51.3837, 1.3211
OS grid ref: TR311701