Chrysaora, Durgan, Cornwall, UK

Single small compass jellyfish, tentacles missing, at private beach below Glendurgan Gardens on the Helford "River" (actually drowned valley). G. Peterken quote from preface to "The Ancient Woodlands of the Helford River" by O. Rackham (late of Corpus Christi College, Cambridge): "... it is possible to watch jellyfish pulsing away below the overhanging oaks of ancient woodland." So it is.