STALK-EYED CRUSTACEA 235 



being the largest. There is a notch in the centre of the 

 superior border of the buccal margin ; this border is 

 continued to the anterior external angle of the buccal 

 cavity in an S-shaped ridge, which is, over the external 

 angle, cut into six little rounded teeth ; from the centre 

 of these teeth there is a raised narrow margin to the 

 sides of the buccal cavity. 



The abdomen is six-jointed in both sexes ; that of the 

 female is broadest at the junction of the third and fourth 

 joint ; that of the male is broadest at the posterior margin 

 of the third joint. 



The colour of the male is a magenta - red ; of the 

 female, an olive-green. 



Range. — Venezuela, Berbice. 



Family II. Geocarcinidae. 



GeocarciiiidcB .... Miers. 



GecarcinidcE Dana. 



Gecarcmiens H. Milne Edwards. 



Carapace dorsally very convex, and especially dilated 

 over and in front of the branchial regions, with the antero- 

 lateral margins usually entire and very strongly arcuate, the 

 front of moderate width and strongly deflexed. Orbits and 

 eye-peduncles of moderate size. The fifth joint of the ex- 

 ternal maxillipedes is sometimes inserted at the antero- 

 external angle of the fourth joint, sometimes at the apex or 

 near its antero-internal angle, or it maybe inserted behind, 

 on its internal face, and so be completely concealed in a 

 front view. The legs of the first pair in the adult male are 

 very robust, usually of unequal size. The last joint of the 

 walking legs is nearly always granulated, and armed with 

 spines disposed in longitudinal series. 



