THE GEOLOGIST. 



of the ancient predatory tribes. In the Mansfeld slates thou- 

 sands of fish, with scarce a scale displaced, may still (apparently) 

 present in their contorted frames, the agonies in which their 

 existences were terminated. The tree or plant maybe yet erect — 

 or its prostrate stem, or broken gnarly boughs may be eaten 

 through and through by the sea-wood-wonn (teredo)* — the one 

 grew where it stands, the other, drifted over the wide ocean, speaks 

 in its riddled substance, in silent eloquence of its wanderings. 

 He who carefully notes the position of the fossil, who records 

 faithfuUy where it was found and how, is no mere collector; 

 depend upon it he knows something still more of the value of a 

 fossil. 



One cannot begin everywhere at once, so something must be taken 

 for granted. Among those things I must put upon the faith of the 

 reader, are first, that this world is of very great antiquity ; millions, 

 many thousands of millions — even myriads — of years old. And 

 yet that it shaU not be altogether on trust, we will draw again on 

 one or two common fossils for just evidence enough to show that 

 the strata are not of diluvial origin, but that time was taken to 

 form them. 



What do we see on our own shores where dead shells 

 lie exposed on the surface of the mud ? that worms (serptilse,) 

 zoophytes, sponges, algse, and parasites of aU descriptions encrust 

 them with a little community of life. 



liew 8. Valve of Fossil oyster from tie wiite cliall (of Dover,) with yotmg oyiter attached to i1s9 



internal surface. 

 * The " ship-worm " of the present seas. 



