Recent Literature. 



[Augu 



our author, that the eye-stalks represent limbs, is not apparently 

 well founded. We should therefore regard the number of pairs 

 of appendages as nineteen instead of twenty, though there are 

 twenty segments, the telson representing the twentieth. It is a 



question whether the presence of an "ophthalmic segment can 

 be demonstrated. While treating of the nervous system, an op- 

 portunity of describing the brain after the researches of Dietl in 

 1876, is not taken, although Krieger's more elaborate account ot 

 the brain of the crayfish was not published until the present 

 work appeared. 



