CHAPTER VI. 



CONTEMPOBAEIES AND SUCCESSOES OF EOZOON. 



THE name Eozoon, or Dawn-animal, raises the 

 question whether we shall ever know any earlier repre- 

 sentative of animal life. Here I think it necessary to 

 explain that in suggesting the name Eozoon for the 

 earliest fossil, and Eozoic for the formation in which it 

 is contained, I had no intention to affirm that there 

 may not have been precursors of the Dawn -animal. 

 By the similar term, Eocene, Lyell did not mean to 

 affirm that there may not have been modern types in 

 the preceding geological periods : and so the dawn 

 of animal life may have had its gray or rosy breaking 

 at a time long anterior to that in which Eozoon built its 

 marble reefs. When the fossils of this early auroral 

 time shall be found, it will not be hard to invent ap- 

 propriate names for them. There are, however, two 

 reasons that give propriety to the name in the present 

 state of our knowledge. One is, that the Lower Lau- 

 rentian rocks are absolutely the oldest that have yet 

 come under the notice of geologists, and at the present 

 moment it seems extremely improbable that any older 

 sediments exist, at least in a condition to be recognised 

 as such. The other is that Eozoon, as a member of 



