138 



THE STRATIFIED BOCKS. 



points, we should meet with coral reefs and isles, corre- 

 sponding with the analogous phenomena of the medial and 

 lower formations of the secondary strata. Beds of gre- 

 garious mollusca would offer a resemblance to similar accu- 

 mulations in the ancient deposits ; while the various tribes 

 of zoophytes, Crustacea, and fish, would occupy their respec- 

 tive localities, the sponges and corals inhabiting beds and 

 reefs, the shells frequenting the sands of the shore, and the 

 Crustacea and the fishes strewn over the floor of the ocean ; 

 while the picture would be completed by the exhibition of 

 volcanic agency, exerted both above and below the surface of 

 the waters. Indeed, with the exclusion of the remains and 

 the works of man, we should find a southern ocean of the 

 present day, if changed to dry land, to present a perfect 

 panorama of the most extensive and important formations of 

 the ancient earth, and of the varied phenomena of primeval 

 nature. 



THE STRATIFIED BOCKS. A stratified rock may be de- 

 fined to be one whose upper and lower surfaces are parallel 



FIG. 58. 



to each other ; in other words, which exhibits that division 

 into layers and partings, which is recognised in every aqueous 

 deposit, every quarry of limestone, and every pit of chalk, 

 as in the accompanying illustration (fig. 58). 



