572 CALIFORNIA ACADEMY OF SCIENCES. 



general outline of the carapax; it is anteriorly truncated 

 and furnished with a median groove but has no transverse 

 groove behind the anterior margin. Antero-lateral mar- 

 o-in marked by a ridge which begins near the orbit and 

 runs outward and slightly backward to the side of the 

 carapax where it curves abruptly backwards, becoming 

 faintly marked towards its distal end. Maxillipeds nearly 

 naked, similar in shape to those of P. tuhicola; the last 

 two joints of the palp are more or less grooved on the 

 outer surface and the penultimate joint extends only a 

 short distance beyond the preceding one. Chelipeds 

 rather large, smooth, carpus much shorter than the meros ; 

 hand large, compressed, oblong, but widening slightly 

 distally, and exceeding in length all the preceding joints 

 combined; thumb short, edentulous, directed obliquely 

 downwards and furnished at the tip with a notch into 

 which the point of the movable finger closes ; the mov- 

 able finger is much longer than the thumb, edentulous, 

 and curved so that when it is closed against the thumb a 

 large rounded space is left between them. Ambulatory 

 legs almost entirely naked, more slender than in P. tuhi- 

 cola; the first pair is considerably shorter than the second 

 which is but little shorter than the third; the fourth pair 

 may extend a little beyond the meros of the third ; the 

 tarsi are in all the legs little, if an}^ over one -half the 

 length of the propodi and are curved at the corneous 

 tips. Abdomen of male tapering evenl}^ from the base to 

 the tip ; the last joint is subtriangular, about as broad as 

 long, the apex rounded; the preceding joint has the sides 

 concave but the sides of the remaining joints are straight; 

 the first and second joints are subequal and together about 

 as long as the third; the remaining segments subequal in 

 length. 



Length of carapax, 4.5 mm. ; breadth, 9.5 mm. ; length 

 of third ambulatory leg, 11 mm. 



