KIDSTON: YORKSHIRE CARBONIFEROUS FLORA. 5 



self, with the exception of the records taken on the authority of 

 Artis, Brongniart, and Lindley and Hutton. 



It is not our intention to enter largely into the geology of 

 the area under consideration, but with the object of showing 

 the relationship of the various horizons to each other, a vertical 

 section is given, which is taken from the Geology of the York- 

 shire Coal Field.* 



In this section we have drawn the dividing line between 

 the Middle and Lower Coal Measures at the Elland Flagstone. 

 The members of the Geological Survey on the other hand draw 

 the dividing line below the Silkstone Coal. There is no marked 

 break in the series, but palteontological evidence is strongly in 

 favour of drawing the dividing line at the Elland Flagstone, and 

 this is the view taken b)' many of the Yorkshire Palasontologists. 

 The section gives the names of the various coal seams and corre- 

 lates the different names that had been applied to the same seam 

 in different parts of the county before their identity was known. 

 In explaining this section, the authors of the Geology of the 

 Yorkshire Coalfield say: — 'The main members of the Coal 

 Measure group are shown in the following table. The names 

 borne by coals and sandstones in different parts of the field are 

 arranged as nearly as may be in geographical order, beginning 

 on the left-hand side with the names current in the south- 

 eastern districts. In the same way the average thickness in 

 feet of the various groups on the suuth arc given in the left- 

 hand margin, and those in the north in the right-hand margin.' 



Those interested in the geological structure of the county 

 will find it fully explained in the work already referred to, in 

 which a list of the books and papers relating to the geology of 

 the Yorkshire Coal Field is also included. 



*Mcm(;irs of the Geological Survey of England and Wales. By A. II. 

 Green and K. Russell, cVc. London, 1878. I'age 75. 



