158 CRUSTACEA. 



For a description of the species and their localities, we refer the 

 reader to the excellent work of this celebrated naturalist, who in his 

 labours upon the fossil Crustacea, properly so called, or universally 

 admitted as such, has availed himself of the talents of one of his 

 most distinguished pupils, M. Desmarest, frequently referred to by 

 us, not only with respect to this particular part of the science, but 

 in relation to his work on the living Crustacea. Different naturalists 

 have proposed various generic sections of these fossils; but being 

 restricted to general considerations, I have adopted those presented 

 to us by the best work hitherto produced on the subject. 



