http://www.youtube.com/watch?v=W6jUWSNbbvw
:o
That's scary!
It's a Deepstaria enigmatica, a jellyfish of the family Ulmaridae first described in 1967 by F.S. Russel. The bell of this jellyfish is very thin and wide (up to approx. 60 cm), and resembles a translucent, folding sheet or lava lamp as the animal moves. They are usually found in Antarctic and near-Antarctic seas but have been spotted in waters near the United Kingdom, at depths of 829 to 1830 meters.
Beautiful! I'm inspired--I love jellyfish! Like to create them in my art. Thanks for posting, Tjalle. Thanks for the identification, Stormcrow!
I believe that was a slime that finally got high seas expansion, and fell overboard.