Yep - it's a Scultured Slipper Lobster (Parribacus Antarcticus) my Caribbean fish book states : Slipper lobsters hide in crevices by day and emerge at night to forage out in the open. The flattened, plate-like appendages at the front end of the animal are modified antennae. A small, second pair of antennae protrudes from between them. These animals have no claws and feed mostly on soft-bodied animals. Several species occur in the rgion. P/ antarcticus can usually be identified by the rough texture of the antennae and carapace. It occurs in warm waters throughout both the western atlantic and indo-pacific.

HTH

psss - Found this website a while ago - might be of interest to some
http://www.fishdb.co.uk/