Carapace uncalcified, flexible and elongate. Dorsal margin straight. Ventral margin convex but fairly straight at midlength.
Sexual dimorphism is present.
Posterodorsal gland of right valve on protuberance. Adult furca with 7 claws on each lamella. Eight, all from anchialine caves. Oven Rock Cave, Great Guana Cay, Exuma Cays, and Norman's Pond Cay, Exuma Cays, all on the Great Bahama Bank, Bahamas. Resembles S. sagax from Grand Bahama Island on the Little Bahama Bank.