From a recent trip to Norway there were loads of these jellyfish. They are obviously a very common variety but I'm having trouble putting a name to them other than the 'cross jellyfish'.
They are about 4 to 5 inch across and occur in the UK too, although I do not think I've seen them in the UK
Any information?
Appears to be a hydrozoan... looks like a super huge Eutonina species. But I'm sure its a completely different genus, will check my books at work...
Here... found an online reference. Looks identical to what you have there...