ACADEMY OF SCIENCES. 99 



in the larger cheliped; fingers with numerous tubercles on inner surface. 

 Hinder limbs rounded; the two last joints tomentose. 



Color reddish-brown; fingers slaty. 



Locality, La Paz, L. C. 



The dimensions of a large specimen of each sex are as follows: 



M. M. M. M. 



Greatest width of carapax . 71 60 



Greatest length of carapax 50 41 



Length of larger hand 65 50 



Length of smaller hand . . . . . . 47 39 



Greatest width of larger hand 27 22 



No. 31. Male and female and young. Identity of donor unknown. 



Xantho muttidentatus. Lockington. Proc. Cal. Acad. Sci., Feb. 7, 1876. 

 No. 38. Male, dried. Mazatlan. Hy. Edwards. 



PARAXANTHUS. 



Xantho novem-dentatus. Lockington. Proc. Cal. Acad. Sci., Feb. 7, 1876. 

 San Diego; San Jose Island, Amortiguado Bay. 



Four or five specimens only. Color of carapax in spirits, whitish, with a 

 tinge of red, and with red markings. The front is much more produced than 

 usual in this species. 



No. 32. Male, dried. San Diego. Hy. Hemphill. 



All but one of the specimens from Lower California are smaller than the 

 type specimen which was procured at San Diego, and the carapax is propor- 

 tionally narrower, yet I believe them to be younger individuals of the same 

 species, founding my belief on the prominent, narrow, entire part, curved 

 outline of the antero-lateral margin, without perceptible angle at its junction 

 with tne postero-lateral; and on the character of the left cheliped. the fingers 

 of which are sulcate, and devoid of prominent tubercles on their palmar 

 surlace. 



Xantho spini-tuberculatus. Lockington. Santa Rosa Island, Monterey, San 

 Diego, Magdalena Bay, San Jose Island. 



This species appears to be of common occurrence along the coast from 

 Monterey southward to Magdalena, but to disappear, or at least become rare, 

 in localities further south. 



Dimensions of the largest specimen : 



M. M. 



Greatest length of carapax 30 



Greatest width of carapax 40 



The right hand in this large specimen (a male) is very much larger than 

 the left, but this is not universally the case. 



Color, in spirits: carapax greenish, with maroon cloudings; tubercles of 

 first pair and front of carapax bright red; hinder limbs crossed by maroon 

 bands; fingers black. 



