230 Notes on North American Crustacea. 



Crrapsiis altirrons, nov. sp. 



Orapsus pictus Sauss., Rev. et Mag. de Zoologie, v. 362. (non Latr.) 



A large species intermediate between G. maculatus and O. ornatus, 

 having the projecting front-margin, the narrow cardiac region, the cir- 

 cumscribed yellow spots on the carapax, and the robust feet of the latter, 

 wiUi the short blunt internal suborbital lobe of the former. The sides 

 are more strongly arcuated than in any other species of the genus. The 

 front is perpendicular, very high, with a concave surface, and a very 

 prominent superior margin, the frontal lobules projecting forwards 

 slightly beyond the inferior margin. 



We have no specimens of the Chilian species, G. ornatus, for 

 comparison with ours, but if M. Edwards' short description is 

 correct, that species is quite distinct in its long, acute internal 

 suborbital lobe, projecting beyond the frontal margin. 



G. altifrons is found in great numbers on the rocks of Cape 

 St. Lucas, by Mr, Xautus. 



Geo^rap§us lividus. 



Grapsus lividus M. Edw., Hist. Nat. des Crust, ii. 85 ; Mel. Carcin. 135. 



The meros-joint of the ambulatory feet in this species is 

 somewhat denticulated at the inferior extremity, and not com- 

 pletely unarmed as stated in the descriptions. 



Found at the Tortugas by Dr. Whitehurst. Specimens have 

 also been found at Cape St. Lucas, by Mr. Xantus, which we 

 have referred to this species, although they are darker in color 

 than West Indian examples, being more closely reticulated 

 with purplish. Should they prove distinct, we propose to call 

 the species G. occidentalis. 



The crab under consideration has been found by Mr. Xan- 

 tus and otlier observers at low water, on the rocks of the sea- 



