bubble shell ? ID

I wasn't impressed when Matt (jugglematt) came back from a "nothing" dive at Hyams Beach with this ... I mean, to find such a great critter when I wasn't there to see it!

Still, I am wondering if someone can ID it for us. I have tentatively filed it under bubble shell ...

cheers

Leander

Isn't it a baby or small species of Aplysia?

now that would be too obvious ... a baby sea hare !

If not a baby Aplysia, something closely related.

Guido