Reckon Planes minutus, found wedged among stalks of a huge goose barnacle clump after stormy weather. I still have the shell etc.
No interactions present.
It certainly looks like this species. If you still have the shell,the NHM (Paul Clark) or the National Museum of Wales (Andy Mackie) may be interested in checking it over and (perhaps) adding it to their collections.
Thanks for the advice Mike. I phoned Andie Mackie & he reckoned it likely & emailed species notes (but also said they've now been seen in quite a no.of places). Anyway I've added p's of the (now discoloured)shell in case that might help identification.
Obviously I cannot be certain enough to add an agreement. But an excellent, well documented, record.
Tales minutus floored me ('stories' perhaps?)
Lat/Lng: 51.6029, -4.3023
OS grid ref: SS406918