92 STALK-EYED CRUSTACEA 



7. Mithrax (Mithrax) pleuracanthus. 



JMitJirax plcuracanthus . . . Stimpson, A. Milne 



Edwards. 



These crabs are very small. 



The carapace is less curved than in MitJirax hispidiis. 

 The regions are clearly delineated, and have also very 

 plain tubercular nodosities upon the branchial and cardiac 

 regions. The teeth and spines of the orbit are more pro- 

 nounced, and those of the lateral edges are wider and 

 more tuberculous. In young specimens the three first 

 lateral projections are completely blunt. 



Range. — Martinique, Guadaloupe. 



8. Mithrax (Mithrax) laevimanus. 



Mithrax IcEvimamis . . Desbonne and Schramm, A, 



Milne Edwards. 



The carapace is smooth, and has only a few round 

 projections resembling M. Jiispidns, only it is not so wide, 

 and the front is much more advanced. The prreocular 

 spines are represented by a round projection of the 

 superior orbital border. The orbital border has three 

 tubercles. The lateral edges have five almost cylindrical 

 spines, simple and directed forwards ; the first and the 

 fifth are the smallest. There are three strong projections 

 on the branchial regions. The basal joint of the external 

 antennas has three blunt spines ; the one, which does not 

 exist in M. Jiispidus, is placed below the insertion of the 

 second joint ; another, stronger, forms the antero-external 

 angle ; the third, of the same size, is placed on the antero- 

 internal angle. 



The sternal plastron, in the male, is deeply notched in 



