Carapace width to 88 mm in males and 68mm in females. Different from L. grandis by a smaller size, a carapace with fewer tubercles and only one anterior marginal tubercle, a rostrum not strongly deflexed and a plush-like coat of short, thick hairs. Chelipeds are much longer in males than in females. Walking legs are short for a spider crab.

Generally found so thickly coveredwith growth that they are hardly recognizable.

Low intertidal zone to 183 m; Redding Rock, Humboldt County, California to Isla Natividad, Baja California, Mexico.