DECAPODA . CANCERIDM. 



BRACHYURA. 



GENUS PILUMNUS 



Cancer, Linn., Pennant, Herbst, 



PiLUMNUs, Leach, Edwards. 



Generic Character. — External antennce long and setaceous ; the 

 basal joint not continuous with the surrounding parts, but sepa- 

 rated by a distinct line, and filling the inner canthus of the orbit ; 

 second joint nearly as broad as it is long, and moveable with the 

 remaining portion ; third joint longer than the second. Internal 

 antennce with the last point of the peduncle club-shaped. Exter- 

 nal pedipalps with the third joint transversely quadrate, tlie 

 antero-internal angle emarginate. Anterior pair o? feet unequal, 

 robust, rounded ; the remaining pairs rounded above, flattened 

 beneath ; the second pair not longer than the third or fourth. 

 Carapace convex, the anterior part much curved from before 

 backwards ; the surface even ; the latero-anterior margin extend- 

 ing backwards as far as the posterior part of the gastric region ; 

 front slightly prominent ; orbits elliptical, the inferior margin 

 spinulose. Abdomen, in each sex, seven-jointed ; in the male, 

 the third joint the broadest, the succeeding ones diminishing regu- 

 larly to the apex ; in the female, all the joints sub-equal. 



