Is this a Nudibranch?

This one has me stumped, not sure if it is a Haminoea of some sort.

Was it moving?It almost looks like a tunicate, but with the debris, it is difficult to make out details. Where was it taken?

I initially thought it was a juv crab of some sort due to the hairy appearance. I took 3 photos and it didn't appear to move. Found at the Gold Coast Seaway SW Wall, Australia which is a very silty shallow muck dive.

There were a lot of Bullina lineata, Bullina nobilis, Bulla angasi about and they normally bury quickly when the light hits them (night dive), this one was not on a sandy patch and was amongst the algae and other muck on a rock.

It does look like a tunicate, doesn't it? But it's an clam in the oddball family Galeommatidae. The foot wraps completely around the 2 shells, and they crawl about like snails. Look for images under the family name, under Amphilepida, Scintilla, and Chlamydonconcha for examples.

Thanks Leslie

Here's a good link:

http://taxondiversity.fieldofscience.com/2011/02/galeommatidae.html