404 Mr. W. N. Lockington on the Porcellanidea 



The larger of the two specimens measures barely three 

 centimetres in length. 



Exact locality unknown. Lower California. 

 This pretty little species is a typical Pisosoma. 



Pacliycheles rudis^ Stimpson. 

 Pachycheles rudis, Stimpson, Ann. Lye. Nat. Hist, N. Y. 1862, vii. p. 76. 



Stimpson states that this species was found " near San Fran- 

 cisco." I have not succeeded in finding it within the bay ; but 

 it may probably inhabit the rocky ocean-beach at no great 

 distance from the Golden Gate. 



The most southern locality I have on record for this species 

 is Santa-Rosa Island ( W. G. W. Harford) ; but among 

 numerous bottles of material from Lower California I find 

 one without a label which contains several young specimens. 



In young individuals the tubercles or large granules of the 

 manus and carpus are less prominent than in the adult. 



The frontal region is densely pubescent, and the surface 

 of the carapax striated toward the margins. 



Pachycheles tuherculipeSj nov. sp. 



Carapax and limbs covered witli dense and long pubescence, 

 except in the central portions of the former ; under surface 

 smooth. 



Front depressed ; central portion triangular, deeply fur- 

 rowed along the median line ; preorbitals acute, deflected ; cara- 

 pax nearly smooth in the centre, tuberculate near and along 

 the margin, somewhat convex. 



Eye-peduncle fitting closely between the pre- and post- 

 orbital teeth. 



Antennae distant from orbit ; peduncles rough. 



Chelipeds and ambulatory feet a mass of tubercles above ; 

 tubercles covered with granules, especially upon the manus. 

 Chelipeds subequal. 



Carpus with a tubercular tooth on the anterior margin at 

 its superior proximal extremity j shorter than the meros when 

 viewed from below. 



Manus more than twice the length of the carpus ; dactyli 

 parallel, hooked at tip, with a smooth rounded ridge along the 

 upperside. 



Length of carapax about 3"5 millims., width about 3*5 

 millims. 



Locality. La Paz, Gulf of California. 



Five specimens of this singular form were found mixed 

 with other species, in one case from La Paz, in others from 

 other ports on the Gulf. 



