PREFACE. Xi 



modern origin of its present surface ; of the 

 deluge, and the subsequent renewal of human 

 society. 



In order to render this Essay more complete 

 and satisfactory, I have illustrated the whole 

 with an extensive series of observations, and 

 have arranged them in such a manner that they 

 will be readily accessible, not only to the natu- 

 ralist, but also to the general reader. 



Since the publication of the former edition 

 of this Essay, many curious discoveries have 

 been made in regard to fossil organic remains ; 

 some of these are included in the Illustra- 

 tions at the end of the Essay, others \yant of 

 room forces us to omit. But we cannot allow 

 the present opportunity to pass, without briefly 

 describing that remarkable fossil animal alrea- 

 dy noticed in a very cursory manner in page 

 266, as we are now enabled to present the 

 English reader with a representation of it from 

 a drawing of Sommerring, in the Denkschriften 



