ON THE ORIGIN OF COAL. IQl 



of sauroid and other fishes, scattered throughout 

 them, as well as by the occurrence of the Unio — 

 a shell resembling the Modiola — and the Micro- 

 conchus, prove that a considerable period of time 

 was requisite for their formation. 



The fossils, in the first case, occur over a space 

 of about two feet, in a bass, which is composed of 

 fine clay, mixed with bituminous matter, resem- 

 bling the indurated black mud which we now find 

 at the bottom of stagnant pools, in which there 

 is much decomposing vegetable matter. After 

 the growth of the vegetables constituting the 

 yard Coal, the subsidence must have been very 

 slow and gradual, so as to allow time for the 

 complete decomposition of all the vegetable matter, 

 and the existence of the animals whose remains 

 are now found there. From the fragmentary 

 state of the portions of fish, mixed with the casts 

 of Cyprides, there is every reason to believe that 

 their edible parts were consumed by the Cyprides, 

 in a similar manner to the removal of decomposing 

 animal matter by the small crustaceae of our 

 modern waters. 



The Bass, over the three quarters seam of Coal, 

 resembles that over the yard mine, in the nature 

 and condition of the organic remains found em- 



