THE EOZOIC AGES. 23 



(2.) In later formations coaly matter is an organic 

 substance, derived from vegetables, and there are 

 large quantities of Laurentian carbon in tbe form of 

 graphite. (3.) In later formations deposits of iron 

 ores are almost always connected with the deoxidising 

 influence of organic matters as an eflficient cause of 

 their accumulation, and the Laurentian contains im- 

 mense deposits of iron ore, occurring in layers in the 

 manner of later deposits of these minerals. (4.) The 

 limestone, carbon, and iron of the Laurentian exist 

 in association with the other beds in the same manner 

 as in the later formations in which they are known to 

 be organic. 



In addition to this inferential evidence, however, 

 one well-marked animal fossil has at length been 

 found in the Laurentian of Canada, Eozoon Canadense, 

 (fig. 7), a gigantic representative of one of the lowest 

 forms of animal life, which the writer had the honour 

 of naming and describing in 1865 — its name of 

 *' Dawn- animal" having reference to its great an- 

 tiquity and possible connection with the dawn of life 

 on our planet. In the modern seas, among the 

 multitude of low forms of life with which they swarm, 

 occur some in which the animal matter is a mere 

 jelly, almost without distinct parts or organs, yet un- 

 questionably endowed with life of an animal character. 

 Some of these creatures, the Foraminifera, have the 

 power of secreting at the surface of their bodies a 

 calcareous shell, often divided into numerous cham- 

 bers, communicating with each other, and with the 



