PEREIONOTUS. 



227 



author in the " Magasin de Zoologie" for 1836. Of this 

 latter genus we have had the opportunity of examining 

 only a single specimen of P. Rissoanus, taken by Mr. J. 

 Gwynn Jeffreys on the shores of Piedmont, but the 

 specimen being small, we were not able to make out 

 the form of the last pair of caudal appendages without 

 dissection, and we felt unwilling to destroy our only 

 specimen. We are therefore led to infer either that 

 Guerin's description of the posterior pair of caudal 

 appendages is incorrect, or that Montagu's specimen 

 belongs to a distinct but closely-allied genus ; and pre- 

 fer to adopt a new generic name, rather than to assume, 

 without further evidence, that so accurate an observer as 

 M. Guerin-Meneville can have been mistaken. 



The accompanying vignette is a scene off Flamborough 

 Head. 



Q 2 



