[Summary]. Periclimenes colemani, a new species of pontoniinid shrimp, is described and illustrated. This species was found at Heron Island on the Australian Great Barrier Reef. It lives in pairs on the test of the sea urchin Asthenosoma intermedium H. L. Clark. The new species is considered to occupy a rather isolated systematic position, most closely related to another echinoid associate, P. hirsutus Bruce. It is also remarkable for its cryptic white, red spotted colour pattern. The associations between Indo-West Pacific Periclimenes spp. and echinoids are briefly reviewed.