NORTH-CAROLINA GEOLOGICAL SURVEY. 195 



ble to compare and infer with certainty. Observation is the 

 way, but the plan of creation makes it possible to deduce a 

 connected history of the past from the dead races, and thereby 

 see at a glance how any former epoch differed from the pres 

 ent, or from those ancient ones with which it was more inti 

 mately connected. 



My object, however, is not so much to direct the student in 

 this chain of reasoning, or so to apply knowledge as to make 

 him acquainted with the external forms of the fossils of 

 the marl beds. The figures and descriptions will enable him to 

 know the objects from their forms, and thereby to distinguish 

 the marl beds which contain them from each other. It is, 

 therefore, a practical subject, and may be studied as such. 

 But the knowledge thus acquired prepares the way for further 

 advances in science. 



The fossils described in this part of the Report, belong to 

 four or five periods, inasmuch as some of them are found in 

 two or more successive ones. These periods have been dis 

 tinguished by the following names which are expressive of 

 certain ideas. Thus, the oldest is the cretaceous or chalk for 

 mation. It is, however, only a small part of it, and that part 

 is the inferior or oldest part of the cretaceous system. This 

 part is widely known as the Green Sand, and has been em 

 ployed extensively as a fertilizer. The 2d, in the ascending 

 order, is the Eocene, which means the dawn of the present, as 

 a few species survive, which were created in this epoch or pe 

 riod. Onty about four per cent., however, have lived on 

 through all the vicissitudes of the times. The third, is the 

 Miocene. Of the animals created during this period, more 

 than half have perished, and we know them only through 

 their remains. The fourth is the Pliocene, the animals of 

 which less than half have perished. The fifth, the post-Plio 

 cene, is known by its fossils being similar to those which now 

 live, excepting five or six per cent. Hence, it may happen 

 that one of the four species of animals which survive, and 

 which was created in the Eocene period, may be found in all 

 the succeeding beds, but it is evident it will be associated in 



