278 



ALPHEAD^. 



DEC A POD A. 



MACROURA. 



ALPHEAD/E. 



Nika Couchii. Mihi. 



Specific Character. — Didactyle hand shorter than the wrist ; the former slightly, 

 the latter more considerably curved. Middle plate of the tail attenuated towards 

 the extremity, not furrowed. 



The distinctive characters of this new and interesting 

 species are, with the exception of those given above, 

 mostly comparative. The whole animal is longer in \)V0- 

 portion to its other dimensions. The carapace, which 

 extends a little further backwards over the posterior 

 thoracic segment at its junction with the abdomen, is 

 longer and more slender ; the plates of the external an- 

 tenna) are longer, and rather tapering towards the extre- 

 mity. The legs generally are altogether longer and more 

 slender ; the didactyle hand and wrist of the first pair are, 

 however, shorter, and both, but particularly the wrist, 



