Hi - we came upon this large jellyfish on Newborough beach, Anglesey 19th June. I've just read in the local paper that there have been sightings of a large jellyfish thought to be a lion's mane jellyfish (i think that's what it said) - could that be what this is? It was about 1.2m in diameter.
This certainly has the look of a Lion's Mane Jellyfish, although the characters that help distinguish it are more difficult to see when out of their 'natural environment'!
The bell (or central domed part) of this species of jellyfish is distinctly lobed (divided into 8) and brightly coloured, ranging from red, to orange, to yellow. Lion's Mane Jellyfish have brown or red coloured ‘arms’ and eight separate clusters of long tentacles.
For further 'jellyfish facts' have a look here:http://www.jellyfishfacts.net/lions-mane-jellyfish.html
It's incredible that such an obvious case as this, is still rated unanswered,after over 5 months, after 3 have identified it & when it's quite clear there's no other possibility.
It's Cyanea capillata.
you'll find plenty of beached lion's manes looking like this if you go to ispot.org.uk & in the search slot enter Cyanea capillata. Uk has only 6 sizeable jellyfish & only 2 are similar,lion's mane & the related C. lamarckii, or "blue jellyfish",& the latter's usually blue or purplish & anyway only reaches 30cm (about 1 foot!), so much smaller