176" 



respectfully to recommend them to the consideration of the 

 practical miner, as strong and important lines of demarcation 

 in the Yorkshire Coal Strata. The remains of fishes of the 

 same species do indeed occur in the roofs of several other 

 beds, so that they alone are not sufficient to identify the two 

 beds which have been the subject of our present remarks ; but 

 these taken in connexion with the mineralogical character of 

 the beds in which they are found, the peculiar manner in 

 which they are imbedded, and taking into account all other 

 available evidence, they can scarcely be mistaken for any 

 other beds which occur in the Yorkshire series. 



" But if we may regard these two beds as in reality beds 

 of coal, their investigation will throw considerable light upon 

 the question regarding the origin of that most valuable 

 mineral. Every one who examines either of these beds will 

 be convinced that it has been deposited in a state of very fine 

 mud, and consequently under circumstances of great tran- 

 quillity. The scattered teeth and scales are all laid as they 

 would be, if left to their own gravity, when sinking into a soft 

 and yielding substance. This tranquillity is still more remark- 

 ably indicated by the high state of preservation in which we 

 find the Coprolites. In general we may suppose that these 

 frail substances, when first deposited, had become immediately 

 enveloped with the soft mud into which they had fallen, and 

 that they had never been disturbed until this substance had 

 hardened around them. 



" But whilst we have these evidences of the extreme tran- 

 quillity of the waters beneath which these beds had been 

 formed, it is surprising that the teeth, scales, and other parts 

 of fishes are all detached and fragmentary. In the Magnesian 

 Limestone, the Lias, the Oolite, and in other formations, it 

 is very common to meet with whole fishes, but in these two 

 beds of the Coal formation we find the very reverse. 



" Some of the Coprolites might possibly have been preserved 



