42 PRINCIPLES OF PALAZZONTOLOGY. 
rarely find many of the primary formations following one 
another consecutively and in their regular order. 
In no case, however, do we ever find the Devonian resting 
upon the Carboniferous, or the Silurian rocks reposing on the 
Devonian. We have therefore, by a comparison of many 
different areas, an established order of succession of the strati- 
fied formations, as shown in the subjoined ideal section of the 
crust of the earth (fig. 17). 
The main subdivisions of the stratified rocks are known by 
the following names :— 
1. Laurentian. 
2. Cambrian (with Huronian ?). 
3. Silurian. 
4. Devonian or Old Red Sandstone. 
5. Carboniferous. 
Oats ae LN ew Red Sandstone. 
7. Triassic 
8. Jurassic or Oolitic. 
g. Cretaceous. 
1o. Eocene. 
11. Miocene. 
2. Phocene: 
13. Post-tertiary. 
