278 



DEC APOD A. 



MACROURA. 



ALPHEAD^E. 



ALPHEADM. 



Nika Couchii. Mihi. 



S-pcciJic 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 ahove, 

 mostly comparative. The whole animal is longer in pro- 

 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- 

 tennoe 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, 



