Coriocella sp.

Comment from the photographer: Hi Erwin, I just got back from Komodo last month and was wondering what class does this creature in the pics falls into. I tried to refer to nudibranchs encyclopedia by neville coleman, but to no avail - most probably it falls under a different class like sea slugs or sea hares for eg.. do you have any idea what this is? Thanks in advanced. Regards, Shariza