172 S. T. Smith on American Crustacea. 



than in the female, the chelipeds are stouter in proportion, and the 

 ambulatory legs are somewhat less hairy. The carapax is of the 

 same weak consistency, and the external maxillipeds of the same 

 form, as in the female. The abdomen is quite narrow and all the seg- 

 ments are distinct. The margins are very straight to the sixth seg- 

 ment, which is slightly contracted, and the extremity is broadly 

 rounded. 



A number of specimens give the following measurements, which are 

 only approximately correct, on account of the soft and flexible nature 

 of the carapax. 



The genus Plnnaxodes is quite distinct from the typical species of 

 Fabia Dana, in the form of the external maxillipeds, which are nearly 

 longitudinal and much as in Pinnixa, with which, in fact, Heller com- 

 pares them, while in Fabia suhquadrata, they are oblique and resem- 

 ble those of Pinnotheres. The carapax also is quite difierent in form, 

 and in Fahia^ the sulci which extend back from the orbits are very 

 deep and there is no median sulcus on the front, while in Plnnaxodes, 

 the sulci from the orbits are very slight, not more distinct than the 

 median. 



Family, Dissodactylid.^. 



This family, which is here established for the following genus, 

 appears to be most nearly allied to the Pinnotheridm, but diifers from 

 that family, and in fact from all other Ocypodoidea, in the structure 

 of the palate, or endostome, which is not divided by a median ridge 

 separating the efferent passages. 



Dissodactylus,* gen. nov. 



The carapax is depressed, the dorsal surface is smooth and not areo- 

 lated, and the front is narrow and horizontal. 



The eyes are very minute, being much smaller even than in the 

 Plnnotheridae. 



The epistome is very short, so that the labial border approaches 

 very near to the front, leaving only a narrow space which is nearly 

 filled by the antennulse. The labial border is regularly concave, as 

 seen in a front view, is not interrupted in the middle by any projec- 



* AfCCTof, duplex; (Jd/crf/lof, digitus. 



