206 I^otes on North American Crustacea. 



the carapax is at this shoulder, and between it and the orbit, the margin 

 is thick, obtuse, perfectly straight and smooth. Behind the shoulder- 

 tooth there are two small teeth on the antero-lateral margin, rather 

 sharp and crested. Front deflexed, with a reticulated surface. Sub- 

 hepatic regions also reticulated, that is, covered with minute cavities the 

 parietes of which form a fine network. Chelipeds angular, with reticu- 

 lated surface ; upper side of carpus somewhat dilated, with a strong 

 outer, inner, and posterior tooth or angle. Ambulatory feet very much 

 compressed, almost laminiform, with sharp, smooth, lamelliform crests 

 above. In the penult and antepenult joints of the first two pairs of 

 ambulatory feet, there is also a longitudinal crest on the side of the 

 feet, the spaces between the crests being deep cavities. Sternum and 

 inferior side of feet pubescent. 



It is slate-colored, with the antero-lateral margins and chelipeds red- 

 dish-white. Length of the carapax in a male, 0.25 ; breadth, 0.34 inch. 



Cape St. Lucas. J. Xantus. 



* 



Xaiitho vittata, nov. sp. 



Carapax depressed, rather narrow, anteriorly rather convex, and with 

 a produced front. Dorsal surface distinctly divided into regions by 

 sufiiciently deep furrows ; the gastric region subdivided into three lobules ; 

 and the branchial into two by the transverse sulcus arising at the lateral 

 angle. Surface naked, somewhat punctate, and transversely rugulose 

 anteriorly. Lateral and posterior margins ciliated beneath. Antero- 

 lateral margin eight-toothed ; teeth small, sharp, narrower than their 

 interspaces at the base. Anterior tooth situated at a double interval 

 from the angle of the orbit. External marginal lobes of the orbit pro- 

 minent. Front horizontal, much projecting ; margin slightly convex, 

 not toothed, but sparsely ciliated. Chelipeds somewhat rugose above. 

 Ambulatory feet ciliated. Abdomen in the male narrow ; terminal 

 joint scarcely longer than broad, with rounded extremity. Color yel- 

 lowish-grey ; carapax with eleven longitudinal stripes of red. Leng-th 

 of carapax in a male, 0.5 ; breadth, 0.6V inch. 



It is allied to X. sexdecem-dentatus^ but the dorsal surface is 

 distinctly areolated, and the antero-lateral teeth do not touch 



