Notice of Dr. MantelVs Medals of Creation. 115 



YII. The Saliferous, or New Red Sandstone — two prin- 

 cipal and eight inferior divisions. 



VIIL The Carboniferous — three principal and seven inferior 

 divisions. 



IX. The Devonian, or Old Red system — two divisions. 



X. The Silurian system — two principal and five subdivisions. 

 XL The Cambrian, or Schistose system — three subdivisions. 



XII. Hypogene rocks. 

 Metamorphic — two divisions. 



XIII. Plutonic 



XIV. Volcanic rocks — two divisions. 



It will be observed that the peculiar province of this work 

 ceases with division XI, and nearly with X. No rocks below 

 these have been proved to be fossiliferous, and the inferior region 

 is the domain of the rocks of fire, in which had there ever been 

 any fossil bodies embraced, they would have been obliterated. 



In his third chapter, the author cautions collectors against 

 throwing away shells, bones, &c., because they appear little 

 altered — for they may be in that condition even in very ancient 

 strata — shells retaining their pearly lustre, and even their liga- 

 ments ; and on the other hand, in very recent formations they 

 may be completely silicified, or otherwise mineralized. He warns 

 his reader also against mistaking incrustations for petrifactions ; 

 depositions of lime, for example, often take place in mineral 

 springs, which merely enclose the foreign body without altering 

 its nature, and some of these things are prepared by art, as birds' 

 nests, and even the birds themselves. 



Dr. Mantell, after pointing out the peculiarities of fossil bones, 

 gives copious and excellent directions for extracting them, re- 

 uniting their dissevered parts, and preserving them ; and surely 

 no man has a better right to speak on this subject than he, for 

 he has been singularly industrious, persevering, and sagacious, in 

 discovering and bringing into union the fragments of skeletons, 

 especially of the huge Iguanodon, his own fossil wonder. 



The introduction to the history of fossil vegetables is brief, 

 graphic, and lucid, and from it we cite the following passages. 



" The remains of the vegetable kingdom are presented to the 

 notice of the geologist, in various conditions ; in some instances 

 but little changed in their aspect, as in the recent accumulations 

 of mud and silt at the bottom of lakes and rivers, and in mo- 



