Shrimp - Body transparent except where pigmented. Rostrum very small/spinelike or absent. Eyes covered by carapace, hands chelate, one chela powerfully developed. One chela usually and about equal; inverted so dactyls are below. Dactyls of ambulatory legs slender and bifid. Chelae with fingers not longer than palm. Length to about 30mm.

Under low intertidal rocks, logs, and debris on protected shores, and sometimes in tunnels of blue mud shrimp, Upogebia pugettensis and the bay ghost shrimp Callianassa californiensis, on mud flats in bays.

Sitka (Alaska) to Dana Point (Orange County).