DECAPODS I8l 



The characters most useful in determining the species are given below : 



The carapace is roughened antero-laterally, but not conspicuously so. 



The frontal lobes are slightly sinuous and oblique, the outer tooth 

 faintly indicated. 



The anterior margin of the third antero-lateral tooth (or tooth N of 

 Dana) is in line with the truncate margin of the second tooth or the one 

 coalesced with the outer orbital tooth. 



The carpus of the chelipeds is slightly roughened. 



The hand is smooth, without a tooth on the upper margin ; the proxi- 

 mal end of the inner margin of the upper surface is, however, well 

 marked. 



The dark color of the fingers does not run back on the palm. 



The carpal joints of all the ambulatory legs are slightly bilobed on the 

 anterior or upper margin. 



The propodal joints have a convex anterior margin without lobes. 



Dimensions. Male, length 22.5 mm., width 33.8 mm., proportion of 

 length to width 1:1.5, fronto-orbital width 16 mm., proportion of fronto- 

 orbital width to width of carapace i : 2.11. 



LOPHOPANOPEUS FRONTALIS Rathbun. 

 Plate vii, fig. 8. 



Distribution. San Diego, California. The locality ' Monterey ' cited 

 for this species is an error. 



The carapace is almost smooth. 



The frontal lobes are markedly oblique and sinuous, the middle lobes 

 very convex. 



The third antero-lateral tooth is more produced than the second tooth. 



The carpus of the chelipeds is smoother than in L. bellus. 



The hand is smooth, with a large tooth projecting inward on the inner 

 side of the upper margin and extending half the length of the upper 

 margin. 



The dark color of the fingers runs back on the palm ; in this respect 

 differing from all other allied species. 



The carpal joints of all the ambulatory legs are slightly bilobed on 

 the anterior or upper margin. : 



The propodal joints have a convex anterior margin, but are narrower 

 than in L. bellus. 



Dimensions. Male, length 17.2 mm., width 23.7 mm., proportion of 

 length to width i : 1.32, fronto-orbital width 1 2.5 mm., proportion of fronto- 

 orbital width to width of carapace i : 1.9. 



