]!fotes on North American Crustacea. 185 



Herbstia parvlfrons. 



Herhstia parvifrons Randall, Jour. Acad. Nat. Sci. Philad. viii. 107. 



Our specimen is an adult male, in which the carapax is 

 0.67 inch in length, the chelipecls I.IY, and the first pair of 

 ambulatory feet 0.93 inch. It agrees pretty well with Ran- 

 dall's description, except that the carapax is naked, and the 

 hands entirely destitute of spines, with a strong tooth on the 

 dactylus in the gape of the fingers. All the spines are blunt 

 at the tip. 



It was taken at Cape St. Lucas by Mr. Xantus. 



An attentive consideration of the characters of the rostrum, 

 orbits, and antennas, as well as of the excavated fingers, leads us 

 to refer the genus Herhstia to the vicinity of Mithrax., rather 

 than to that of Pisa and Tlijas^ where it has hitherto been 

 placed. 



Herbstia depressa, nov. sp. 



Carapax much depressed, generally covered with scrdes adhering to 

 a slight pubescence easily detached, beneath which the surface is glabrous, 

 and less tuberculose than in H. coiidyliata. A median pi'otuberance on 

 the gastric, and one on the cardiac region ; two tubercles on the intes- 

 tinal region in a transverse row. Lateral and posterior margins armed 

 with small subspiniforra tubercles. A stout spine on the hepatic region. 

 Rostrum rather short and broad, cleft for one half its length ; horns 

 triangular, acute. Frontal region and surface of the rostrum with a 

 median longitudinal sulcus between two short prominent ridges. 

 Praeorbital teeth, orbits, and antennae, nearly as in H. condyliata. Basal 

 spine of external antenna? long, projecting almost as far as the horns of 

 the rostrum. Exognath of external maxillipeds broad, fusiform, almost 

 angular at middle of the external margin. Chelipeds shorter than 

 the first pair of ambulatory feet ; meros armed with one row of spines, 

 and elsewhere smooth ; carpus with numerous ver}^ short spines on the 

 upper surface ; hand glabrous. Ambulatory feet slender, hairy above; — 

 those of the second pair two-thirds longer than the carapax; meros-joint 



