WEST AMERICAN CRUSTACEA. 5^1 



men of the male wider at base than the exposed sternal 

 area on either side and tapering from the third joint, be- 

 yond which the sides are somewhat concave, to the rounded 

 tip; the first and second segments are short and subequal; 

 the four succeeding segments are subequal in length; 

 the last segment is much broader than long and evenly 

 rounded. 



Length of carapax, 4 mm.; breadth, 10 mm. 



This species is usually found in the leathery tubes of 

 annehds. The legs and portions of the carapax are cov- 

 ered with a short pubescence, but the upper surface of 

 the carapax is usually naked and often marbled with 

 patches of color. There are often two ridges which ex- 

 tend backward from near the middle of the antero-lateral 

 margins to within a short distance of the posterior margin 

 of the carapax. In some specimens these ridges are quite 

 distinct but in others they are scarcely visible. 



Numerous specimens from Trinidad, Cape Mendocino 

 and Bodega Bay. 



This species is closely allied to P. tomcntosa L., but 

 differs from it in the relatively greater width of the car- 

 apax which is naked and furnished with much laro-er 

 punctations, in the much smaller chelipeds, in the more 

 slender ambulatory legs with relatively longer and more 

 slender tarsi. In P. tomcntosa there is a curved line of 

 small pits behind the gastric region, a character which is 

 absent in our species. 



PiNNIXA LITTORALIS Sp. nOV. 



Carapax naked, flattened above; behind the median 

 region is a transverse depression followed by a transverse 

 intumescence behind which the carapax curves strongly 

 downwards to the slightly concave posterior margin. The 

 front is not strongly depressed and projects beyond the 



