506 BULLETIN 152, UNITED STATES NATIONAL MUSEUM 



Diagnosis. — Short-hairy over all its dorsal surface. Carapace 

 largely flat; five lateral spines, first two small. Infero-distal half 

 of outer surface of major palm naked, but mostly rough with tubercles 

 and granules. 



Description. — A much flattened species, carapace deflexed in ante- 

 rior third, covered with a short, dense, tough pubescence, each hair 

 straight, regularly tapering. When the hairs are removed, the out- 

 lines of the mesogastric region are distinct, and three or four spinules 

 near antero-lateral margin. Front with margin hairy and spinulous 

 with 10 or 12 spinules, median sinus V-shaped, lateral lobes scarcely 

 separated from median and less advanced. Margin of orbit armed 

 with about 11 conical spines. Five antero-lateral spines, the first 

 two very small, equal, close together at base, and shorter than the 

 remaining spines; third spine with a small one on its posterior slope; 

 all have one or more accessory spinules. Pubescence of ventral 

 surface shorter than that of dorsal; subhepatic region spinulous and 

 subbranchial region granulous. Ridge on endostome distinct. 



Chelipeds very unequal, upper surface covered with hair and 

 short conical spines which become acute tubercles and then granules 

 lower down on the outer surface of the palms, there forming irregular 

 longitudinal lines; major palm naked toward fingers and lower edge, 

 punctate and finely granulous; fingers short, stout, gaping; dactyls 

 tuberculate above near base. Legs broad, hairy, spinulous above. 



Color. — In alcohol, hairs yellow, carapace red mottled with pale 

 yellowish, spines and fingers brown. 



Measurements. — Male (17415), length including spine 13, width 

 including spines 18, excluding spines 16.4, fronto-orbital width 11.4, 

 width of front 5.5 mm. 



Range. — Gulf of California, Mexico. 



Material examined. — La Paz; L. Belding; 5 males, 2 females (4628). 



San Francisquito Bay; April 9, 1911; Albatross; 1 female (60033), 

 1 female (Amer. Mus.). 



San Luis Gonzales Bay; March 27, 1889; Albatross; 8 males, 13 

 females (17415); 1 male is holotype. 



Tepoca Bay; April 25, 1921; Fred Baker, Exped. California Acad- 

 emy of Sciences; 2 young females (Cal. Acad. Sci.). 



Gulf of California; 1921; Exped. California Academy of Sciences; 

 1 male (Cal. Acad. Sci.). 



PILUMNUS DEPRESSUS Stimpson 



Pilumnus depressus Stimpson, Ann. Lye. Nat. Hist. New York, vol. 10, 1871, 

 p. 109 [19] (type-locality. Cape St. Lucas; type not extant). 



Diagnosis. — Carapace and outer surface of major cheliped mostly 

 naked. Lateral and orbital margins dentate. 



Description. — "Body depressed; carapax for the most part flattened 

 and naked, but slightly curved, pilose and roughened toward the 



