50 BULLETIN 166, UNITED STATES NATIONAL ftlUSEUM 



Description. — Allied to H. arcuata. Carapace in the old hairy 

 above and below, concealing the granules; in the young the surface is 

 nearly bare. Anterior margin broadly rounded, edge broken by a 

 marked median incision and by distinct notches at insertion of the 

 antennae. Four or five white subspiniform teeth on each frontal 

 lobe; and 8 or 10 on each margin of the carapace behind these lobes. 

 Some obtuse denticles irregularly disposed and little prominent on the 

 supero-external border of the orbit, as on the inferior lobe. Lower 

 surface of facial region sparsely granulated, granules separated by 

 smooth spaces. Merus of outer maxilliped more plainly squarish than 

 in //. sabulosa; its anterior border is much shorter than the lateral 

 borders and scarcely longer than half the total length of the two pre- 

 ceding articles. The endostome has two broad, obtuse, longitudinal 

 prominences. The large granules on the outer surface of the manus 

 are concentrated on the middle half; they are numerous on the supe- 

 rior face of the dactyl and the inferior face of the fixed finger; the car- 

 pus, beside the prominent border, has a spinule at the distal corners. 



Color. — Uniformly reddish (Bouvier). 



Measurements. — Male (66790), length 12.7, width 13.3 mm. 

 Female (40474), length 18, width 19.5 mm. 



Range. — Mexico to Peru; 3 to 60 fathoms. 



Material examined. — See table 13, page 52. 



HYPOCONCHA LOWEI Eathbun 



Plate 8, Figures 5, 6 



Hypoconcha lowei Rathbun, Proc. Biol. Soc. Washington, vol. 46, p. 149, 1933 

 (type locality, San Felipe, Gulf of California; type female, U.S.N.M. no. 

 67575). 



Diagnosis. —Carapace not produced laterally in a narrow lobe. A 

 strong, conical spine on lower border of orbit. Two spines in a longi- 

 tudinal row on carpus of cheliped. 



Description. — Surface hairy above and below. Anterior margin of 

 carapace arcuate, very slightly sinuous. Lateral angle bluntly rounded, 

 not forming a distinct lobe as in H. sabulosa and kindred species; 

 posterolateral borders rapidly converging. A marginal row of four 

 distant spines on either side of the front, the anterior spine over the 

 orbit. Lower surface of carapace mottled with acute granules but 

 not sculptured. A short spine at angle of buccal cavity. Ischium of 

 outer maxilliped coarsely granulate. Carpus of cheliped with two 

 long spines inclined distad in a median row. About 10 or 12 pointed 

 tubercles scattered through middle of outer surface of manus; fingers 

 finely granulate. 



Measurements. — Male, length of carapace 16.4, width 17 mm. 

 Female holotype, length 20, width 22.3 mm. 



Range. — Mexico to Ecuador; to a depth of 55 fathoms. 



Material examined. — See table 14, page 53. 



