ID needed for SoCal invert

[Reeveseye]

My wife and I were diving off Scorpion Anchorage at Santa Cruz island on Thursday. We saw a lot of these critters wedged into cracks in the rocks. They were an inch or two wide, but it was difficult to tell how long they were since they were in the rocks. Many had open star-shaped "mouths" that had dark leafy extensions coming out of them. The entire dive was in the 20' - 40' depth range. Any ideas?

 

[MarkH]

Looks like a burrowing cucumber (slipper?).

 

[drbill]

Possibly a crevice cucumber, John.

 

[archman]

Could someone drop a genus or Family name? I like learning about west coast invertebrates.