Help - Please ID what is attached to the Jelly Belly...

Hi All - We found a large jelly fish with another animal growing off the back of it. For the life of us we cant work out what it is, it has all the characteristics of a barnacle but no hard shell, it was completely soft and growing from inside the outer layer of the bell of the jelly!!!!!!!!

Have any of you see anything like it?

The jelly would have been 15cm diam and the thing had a stem of about 4cm and top section of maybe 3cm!!!

Please see pictures to ID here and here.

Thanks

You were right - it's a barnacle, called Alepas pacifica. Here's a bit about them - http://jellieszone.com/hitchhiker4.htm