GRAPSOIDEA. 339 



carapax arcuate, anterolateral bi-emarginate. Epistome very 

 short. Third joint of outer maxillipeds as long as broad. Ante- 

 rior feet rather stout ; hand above small pustulate, externally and 

 below smooth ; arm with five or six teeth at anterior apex. Eight 

 posterior feet much compressed, third joint of posterior pair entire 

 at inferior apex; penult joint scabrous above. 



Plate 21, fig. 3 a, animal, natural size ; b, abdomen and sternum of 

 male; c, outer maxillipeds, natural size; d, hand, natural size; e, 

 spine of tarsus. 



Valparaiso, Chili; Callao, Peru. 



Length of carapax, seventeen and one-third lines; breadth, nineteen 

 lines; length of front, six and three-fourths lines; breadth of front to 

 front of praemedial areolets (which but slightly project), two and one- 

 fourth lines. Colour, finely lined and spotted irregularly with brown- 

 ish black or black, with intervening spaces a little yellowish. 



Sides of carapax much arcuate. The species is near O. variegatus; 

 but according to Edwards's description of that species, and the figure 

 in Guerin's " Iconographie," it has the third joint of the outer maxilli- 

 peds much oblong, while in this species, the joint is not longer than 

 broad. 



The figure in the Voy. de l'Uranie, under Freycinet, pi. 76, f. 2, 

 may be this species. 



G. planifrons, Dana, Proc. Acad. Nat. Sci. Pkilad., 1851, v. 249. 



Grapstjs longitarsis. 



Carapax nudus, regione medland granulatus, f route abrupto, perangusto, 

 lateribus parce arcuatls, margine antero-laterali 1-emarginato. Arti- 

 culus rnaxiUipedis externi Stius vix oblongus. Epistoma breve, utrin- 

 que acut& cristatum. Pedes antici sat parvi, manu carpoque supra 

 parce gramdatis, manu extus fere Iwvi, infra leviter costatd. Ikdes 

 postici 7iudi; tar so elongato, spinulis dorsi multo brevioribus. 



Carapax naked, median region granulate, front abrupt, very narrow, 



