PREFACE. 



Vll 



too partial an estimate, that I should take charge of 

 such works as he was then engaged on. It was in 

 this way that I edited the " Memoir on the Tertiary 

 Fluvio-Marine Formation of the Isle of Wight." 



When, somewhat later, it was proposed that I 

 should undertake the continuation of the " Natural 

 History of the European Seas," I shrank from the 

 difficulty of the task ; but I saw that the com- 

 pleted portion of the work was too slight to be 

 issued by itself, and I was unable to find anything 

 by the author which could be added, and it was 

 solely to promote the publication of what compe- 

 tent judges assured me ought not to be withheld, 

 that I undertook to carry out, to the best of my 

 ability, the plan of the author, as that may be 

 gathered from page 16, and some other passages. 



For a continuation to be successful, the graft 

 must be better than the original stock. The sub- 

 ject of the present volume partakes, necessarily, of 

 the nature of an enumeration, and it was not an 

 encouraging task to carry on my friend's facile style 

 of natural history narrative. Again, though he 

 repeatedly admits that the present is insepa- 

 rably connected with the past, yet in reviewing 

 my portion of this joint volume, I feel that I may 

 be charged with having treated the subject too 

 often from a geological stand-point, and that my 



