150 BULLETIN dl, UNITED STATES NATIONAL MUSEUM. 



Chelipeds large; chelae rhomboidal, increasing greatly toward fin- 

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

 tal, a little curved or convex beneath, of nearly equal Avidth 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, 

 nearl}"" 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, Avidth 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 (4558G). 



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 (5712, M. C. Z.). 



PINNIXA MINUTA Rathbnn. 



Pinnixa minuta Rathbun, Bull. U. S. Fish Conim., vol. 20, for 1900, pt. 

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

 holotype, Cat. No. 2376S, 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 Avould run behind 

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

 Eegions 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 coarselj^ granulate. Front truncate, non-projecting. An- 

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



