Unnamed crab?

The only reference I can find for something like this crab is an unnamed Huenia sp.

Does anyone know any more about it, like named or not, Huenia or something else?

Taken during the day at 20m deep at Wickham Island, Morovo Lagoon, Solomon Islands.

Front:

and back:

Thanks!

Looks like the Halimeda Decorator Crab to me. Huenia sp. as you suggested.

This one is Huenia proteus. Very nice pics!