JVotes on North American Crustacea. 199 



tips. Praeorbital tooth small but distinct and rather prominent. The 

 rostrum in the outline of its upper side, is oblong, in length about 

 equalling the distance between the tips of the praiorbital teeth, with sides 

 slightly converging to a place near the extremity, where they abruptly 

 run to a triangular point. In its other characters, the rostrum is thick, 

 with its upper and lower surfaces a little concave ; the lower surface is 

 triangular in shape, narrower than the upper, and separated from it by a 

 deep lateral groove. Chelipeds pubescent; carpus acutely carinated 

 externally ; hand broad, compressed, with the upper margin acute or 

 crested, crest laminiform, very prominent above the insertion of the 

 dactylus. Ambulatory feet slender, with no vestige of a thumb-process 

 on the penult joint, excepting in the first pair. Length of the carapax 

 in a male, 0.36 ; breadth, 0.27 ; length of first pair of ambulatory feet, 

 0.5 inch. 



It is allied to E. affinis and E. hituberculatus^ but wants the 

 two gastric tubercles, and also differs in the character of the 

 rostrum. 



Found at Cape St. Lucas, by John Xantus, Esq. 



Epialtus long'irostriis, nov. sp. 



Allied to E. affinis, but distinguished by the length of its ros- 

 trum, which forms more than one-fourth the entire length of 

 the carapax, and is slender with parallel sides and truncate tip. 

 The two gastric tubercles are distinct. Post-gastric and cardiac 

 regions rather prominent. Chelipeds as long as the first ambu- 

 latory feet, and rather slender ; hand much more elongated than 

 in E. affinis. Ambulatory feet slender, with no tooth or process 

 on the penult joint except a very slight one in the first pair. 

 Length of the carapax in the male, 0.34 ; breadth, 0.22 inch. 



St. Thomas. A. H. Kiise. 



inimillllS. nov. gen. 



Carapax planulatus, plus minusve subpentagonus, margine antero- 

 lateral! valdc expansus, laminatus et bilobatus, lobis arete approximatis. 



APKIL, i860. -^^ Ann. Ltc. Nat. Hist. Vol. VII. 



