A new species of the hermit crab genus Paguristes, P. haigae n. sp., is described and illustrated from material collected in the Gulf of California, Mexico. Paguristes haigae n. sp. closely resembles P. tortugae Schmitt, 1933, from the western Atlantic and P. aztatlanensis Glassell, 1937 and P. oculiviolaceous Glassell, 1937, both previously known from the eastern tropical Pacific. Paguristes aztatlanensis features a proportionally much longer shield than P. haigae n. sp., an acute rostrum, longer than in P. haigae n. sp, and its ocular peduncle is proportionally shorter than in the new species; pereopods 2 and 3 are proportionally longer in P. aztatlanensis than in P. haigae n. sp. and third maxilliped of P. haigae n. sp. is armed while it is unarmed in P. aztatlanensis. P. oculiviolaceous posseses a relatively much longer antennule than P. haigae and the armature of the carpus of chelipeds varies in these two species. Paguristes haigae n. sp also shows somewhat resemblance to P. bakeri Holmes, 1900 and P. holmesi Glassell, 1937, but these two species have the anterior lobules of the telson unarmed while it is armed with 2–4 spines in P. haigae n. sp.
