No interactions present.
You would be better revising this to appear in 'Invertebrates'.
recording wildlife with The Recorder's Year on www.hbrg.org.uk/TRY.html.
Those 'strap-like' markings & the mass of brownish tentacles couldnt be anything else, as other pictures show.
On suject of misID's thought it worth mentioning a mauve stinger (misID'd as moon jelly)at http://www.ispot.org.uk/node/290168 , as it's the only one so far on Ispot. It's battered but comparing it fullscale with the netlinks I think proves it.
Lat/Lng: 56.7616, -2.416
OS grid ref: NO746634