ON THE ORIGIN OF COAL. 175 



lower portion was firmly embedded in the rapidly 

 forming sandstone." Whatever evidence of 

 snags the fossil trees examined by the above 

 learned author may have presented, most of the 

 specimens found standing erect in Lancashire, 

 show every appearance of having grown where 

 they are now found. Remains of Sigillaria can 

 also be generally found in the coal itself. 



Although the stems of Sigillaria have been 

 generally noticed in the roofs of Coal seams, it is 

 by no means to be inferred that they are not to 

 be found in other portions of the carboniferous 

 strata. They no doubt have been found more 

 frequently in the roof than other places ; but that 

 part can be better examined than other strata in 

 a mine. The fossil trees at St. Helens, all Sigil- 

 laria, were four in number, and occurred in a 

 deposit of gray indurated silty clay, lying about 

 eighteen yards two feet above a foot coal, and 

 fourteen yards one foot under a yard seam. The 

 bases of the stems lying about eight feet above a 

 white gritstone rock, and the stems proceeding 

 upwards in the warren, which was completely 

 traversed, as far as it could be traced, by 

 Stigmaria Jicoides ; so if the whole of the rock 

 had been on in the quarry, the stems would 



