396 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL.21 



out spines, sometimes with a cluster of granules. Three blunt teeth on 

 basal antennal article ; rostral, antennal, and preorbital spines shortened. 

 Cheliped of adult male greatly enlarged, palm inflated, fingers gaping 

 widely. Male first pleopod with keel evenly rounded and well separated 

 from short, thickened tip, a supplementary lobe visible in the hiatus be- 

 tween them. (Not true of Galapagos specimens; see Remarks below.) 



Description: Carapace little longer than broad, thick and nodulose, 

 the nodules ornamented sparingly with low granules, appearing almost 

 smooth. The largest nodule the anterior branchial ; this nodule oblique, 

 elongate, and overhanging the lateral wall of the carapace. Behind and 

 below this lobe a short blunt spine or lobe at the lateral angle of the 

 carapace. The most prominent granules on the anterior portion of the 

 carapace, namely, two on the summit of each protogastric lobe, a row 

 of three on each epigastric lobe, one or two at base of each preorbital 

 tooth. Two large tubercles on intestinal region, a submarginal line of 

 granules extending outward from each. 



Rostrum short, deeply divided ; horns broad, inner margin straight, 

 outer margin convex, sinus narrow. Preorbital lobe little advanced, 

 blunt, granulate ; postorbital cup also little advanced. Basal antennal 

 segment broad, bearing two broad blunt lobes on the margin, each lobe 

 outwardly arcuate, also a small subacute tooth at the base of the next or 

 movable segment, and a tubercle on the ventral surface near the postero- 

 external angle. 



Chelipeds of male very strong, one and two-thirds times as long as 

 carapace. Arm tuberculate on upper margin and inner and outer surfaces ; 

 wrist nearly smooth; palm unusually high, its upper length about one 

 and two-thirds times its height; immovable finger a little convex below, 

 a large tooth on the dactyl a little behind middle of gape. Merus seg- 

 ments of legs with [two rows of tubercles and occasional irregular tuber- 

 cles] some conical and subacute ; a few of the same on the carpus, from 

 one to three of these being enlarged ; two tubercles on each propodus. 

 (Rathbun, 1925, modified) 



Material examined: 72 specimens from 26 stations. (See Table 82) 

 From off Concepcion Bay, Gulf of California, to Tres Marias Islands, 

 Mexico; Acapulco, Mexico; Bahia Honda, Panama. In addition to the 

 above, 57 specimens from 12 Galapagos Islands stations. (Garth, 1946, 

 p. 404) 



Measurements: Largest specimen, male: length 13.0 mm, width 12.1 

 mm, rostrum 1.2 mm, width 2.1 mm, cheliped 21.0 mm, chela 10.5 mm, 

 dactyl 4.9 mm, height of palm 4.9 mm, ambulatory legs 12.5, 10.0, 9.5, 



