32 PROCEEDINGS OF THE CALIFORNIA 



almost obsolete; 2d, (E), long and low; 3d, (N), 4th, (T) and 5th, (S), 

 pyramidal and pointed; cardiac region faintly outlined. 1st pair of feet, sub- 

 equal, smooth; hands without crests or tubercles; fingers, black. The mov- 

 able finger of the right hand with a large tubercle at base; 3d, 4th and 5th 

 joints of lour posterior pairs of feet compressed, fingers villous. 



A single male specimen found at Monterey. Length, 0.82; width, 1.10. 



Xanthodes leucomanus. 



This species appears to be very nearly allied to X. HemphHlii, having the 

 front antero-lateral teeth, and areolatiou of that species. If there is any value 

 in the subdivision Xanthodes, both should be included in it, as both have the- 

 first antennal joint connected with the front by a process. The principal 

 difference between the two forms, size excepted, will be found in the net- 

 work of raised lines upon the upper portions of the hand and carpus of the 

 chelipeds iu the present form; and the almost entire absence of the tomen- 

 tosity upon the four hinder pair, which characterizes X. HemphHlii. The 

 dactyli of the chelipeds are of a shining, leucous tint when recent. Several 

 specimens, from Santa Rosa Island (W. G. W. Harford); Monterey (J. 

 G. Cooper); and San Diego (Mr. Henry Hemphill). The carapax of the 

 largest specimen measures half an inch in width, and 0.34 in length. 



Xanthodes ? novem-dentatus. 



Front rather narrow, prominent in centre, and produced forwards; teeth 

 of antero-lateral margin, nine in number; carapace transverse; chelipeds 

 long, the right considerably the larger; manus long and rather narrow, with 

 a slight double crest on the superior margin; corpus with several blunt 

 spines; posterior feet somewhat compressed, with a few scattered hairs on 

 the margins. 



A single male specimen, from San Diego. Total length, 0.94; breadth, 1.25. 



Acanthus. Nov. gen. 



This genus is proposed for the reception of a singular species found at San 

 Diego by Mr. Henry Hemphill. Its characters are: front, two-lobed, with a 

 deep central emargination; antero-lateral margin, front, and whole circum- 

 ference of orbit surrounded by long spines; carapax, narrow; antero-lateral 

 and postero-lateral margins about equal in length; body, thick; abdomen of 

 male, seven jointed. This genus appears to be near Pilumnus, but I can 

 detect no trace of a praelabial ridge. 



Acanthus spino-hirsutus. 



Besides the generic characters given above, this species may be distin- 

 guished by ten spines upon the front, pointing straight forward; a group of 

 four on each side the central emargination, and a single spine close to the 

 outer antenna, the second joint of which reaches nearly to its extremity; 

 six or seven spines on lower margin of orbit, and four larger spines on 

 antero-lateral margin of carapax, besides those on upper margin of orbit. 

 Front portion of carapace and upper parts of all the feet thickly covered with 



