150 BULLETIN 97, UNITED STATES NATIONAL MUSEUM. 



Chelipeds large; chelae rhomboidal, increasing greatly toward fin- 

 gers, a sinus in lower margin near base of thumb; thumb subhorizon- 

 tal, a little curved or convex beneath, of nearly equal width through- 

 out, tip obliquely truncate, lower corner armed with a short, sharp 

 tooth which is crossed by the sharp tip of the dactylus; dactylus 

 oblique, making a large triangular gape with the thumb; a strong 

 tooth at middle of dactylus, a fringe of hair above; a patch of long 

 hair in the gape. 



Merus of cheliped and legs hairy above; merus and propodus of 

 last 2 legs hairy below, carpus and propodus of last leg hairy above. 

 Legs thick, first nearly as long as second, but narrower, second reach- 

 ing to dactylus of third, fourth to middle of carpus of third; merus 

 of last 3 legs convex above, propodus of all tapering, dactylus short, 

 nearty straight, broad at base, acuminate. 



Variations. Chela of male very like that of female except palm a 

 little shorter; in small but mature female, palm still shorter. 



Color. The carapace in alcohol is largely a bluish-purple; a few 

 patches of same color on chelipeds and first three legs. 



Measurements. Female holotype, length of carapace 10.7, width 

 of same 16.2 mm. Male (M. C. Z.), length of carapace 10.2, width of 

 same 15 mm. 



Habitat. Commensal with holothurians. 



Range. Venice, California, to Ballenas Bay, Lower California. 



Material examined. 



Under pier at Venice, California; from cloaca of a sea-cucumber; 

 Venice Marine Biological Station; 1 female ovig., holotype (45586). 



San Pedro, California ; 1901; T. D. A. Cockerell; 1 female (31510). 



San Diego, California; from cloaca of Liosoma arenata [arenicola] 

 Stimpson (now Molpadia arenicola) ; H. Hemphill; received March 

 15, 1874; 1 male, 1 female (5742, M. C. Z.). 



PINNIXA MINUTA Rathbun. 



Pinnixa minuta RATHBUN, Bull. U. S. Fish Comm., vol. 20, for 1900, pt. 

 2 (1901), p. 21, text-fig. 4 (type-locality, Mayaguez Harbor, Porto Rico; 

 holotype, Cat. No. 23768, U.S.N.M.). 



Diagnosis. Carapace narrow, areolated. Dactyli of legs straight. 

 Last 2 segments of outer maxilliped short and stout. Terminal seg- 

 ment of abdomen oblong. 



Description of male. Carapace less than twice as wide as long; 

 an imaginary line connecting the lateral angles would run behind 

 gastro-cardiac suture ; middle portion of lateral margins subparallel. 

 Regions separated by deep furrows; gastric, cardiac and branchial 

 regions separately convex; cardiac region less than twice as wide as 

 long, without crest; upper surface finely granulate, antero-lateral 

 margins coarsely granulate. Front truncate, non-projecting. An- 

 tennae longer than width of front. Merus of maxilliped longitudinal. 



