DECAPOD A. CANCERIDM. 



BRACHYURA. 



GENUS XANTHO, LEACH. 



CANCER, Montagu, Herbst. 

 XANTHO, Leach, Edwards. 



Generic Character. External antennae, very short, the basal 

 joint longer than it is broad, in contact with the front only at its 

 anterior internal angle ; the moveable portion inserted at the inner 

 canthus of the orbit ; the second joint considerably larger than the 

 succeeding ones. Internal antenna placed obliquely immediately 

 under the front. External pedipalps with the third joint quad- 

 rate, the inner anterior angle truncate and slightly emarginate. 

 Carapace very broad, slightly convex from before backwards ; the 

 latero-anterior margins with the front forming a semi-ellipsis ; the 

 latero-posterior margin nearly straight ; front projecting, divided by 

 a slight fissure ; orbits, with a fissure beneath, at the external 

 angle. Anterior legs very large, nearly equal, the fingers pointed. 

 The posterior pairs short, compressed ; the terminal joint very 

 short. Abdomen, in the male, five-jointed ; in the female, seven-- 

 jointed. 



