430 



BULLETIN 129, UNITED STATES NATIONAL MUSEUM 



small, acute, postero-lateral tooth. Carapace along the posterior and 

 postero-lateral borders granular and eroded. Oblique grooves on 

 the branchial region shallower than in coryphe. 



A low tubercle on the basal antennal segment directly behind the 

 insertion of the next segment. The merus of the outer maxilliped 

 appears very short, being overlaid by a prolongation of the inner 

 two-thirds of the ischium. 



Inner margin of arm of cheliped very thin and sharp, unilobate; 

 outer margin bilobate, the lobes coarse, like those of the carapace; 

 a tubercle on upper surface. Wrist rough with tubercles, its inner 

 edge produced, thin, truncate and entire. Hand 

 high, upper edge proximally sharp; immovable 

 finger horizontal; gape in the adult male moderate; 

 a single tooth at the basal two-fifths of the dactylus ; 

 crenulation of finger tips feeble. 



Legs coarsely spinose; from each spine proceeds 

 a tuft of coarse setae; tufts of slenderer setae 

 elsewhere. 



Color. — Brown above; hands dark plumbeous; it 

 is paler beneath (Bell) . 



Measurements. — Male (25673), entire length of 

 carapace 23.2, width 29.4 mm. 



Habitat. — Under stones at low water (Bell). 

 Range. — Galapagos Islands; Chile (Miers). 

 Material examined. — 



James Island, Galapagos Islands; Hassler; 5 males, 4 females 

 (1983, M. C. Z.). 



Albemarle Island, Galapagos Islands; 1898-1899; Hopkins Stan- 

 ford Galapagos Expedition : Black Bight ; January 9 ; 2 males (Stanford 

 Univ.). Tagus Cove, on reef north of Tagus Hill; March 16; 1 male^ 

 1 female, 1 young (25673), 2 males, 1 female, 1 young (Stanford 

 Univ.). 



Chatham Island, Galapagos Islands; Dr. W. H. Jones, U. S. N.; 

 1 male, cast shell (13873). 



Hood Island, Galapagos Islands; April 7, 1888; Albatross; 1 female 

 (21959). 



Charles Island, Galapagos Islands: April 8, 1888; Albatross; 1 

 female (21958). Hassler; 3 males (1 soft shell), 3 females (1981,. 

 1982, M. C. Z.). 



Duncan Island, Galapagos Islands; April 13, 1888; Albatross; 2 

 females (21960). 



Fig. 127.— Mithrax 



(MiTHKACULUS) NOD- 

 OSUS, MALE (25673), 

 MAXILLIPED, X 5.4 



