5<> 



STIGMARIA FICOIDES. 



Careful measurements of the circumference of each of the four primary roots 

 of this specimen gave the following results : 



A. 7 feet 6 inches C. 8 feet 8 inches 



B. 8 „ „ D. 7 „ 6 „ 



We thus see that we have traced the gradual diminution of these roots from a 

 mean diameter of about 32 inches to one of 2\ inches, which, as we have already 

 seen, was not the limit of the reduction. 1 Such a diminution, combined with the 

 fact that no trace of aerial shoots presented themselves in either of these superb 

 specimens, is absolutely conclusive against the hypothesis that these roots are 

 rhizomes. 



In both these examples a thin film of carbonaceous matter invested them 

 throughout all their ramifications. They had evidently been huge and isolated 

 trees growing upon the same horizontal plain, and not portions of a dense 

 forest. To this circumstance, probably, was due the fact that they were not 

 planted upon a bed of coal ; any little vegetable soil that accumulated under their 

 localised shade would attain to no thickness, and would readily be removed by 

 denudation. 



I am indebted to my friend J. "W. Davis, Esq., F.G.S., of Halifax, for the 

 following sections, showing the geological horizon to which these trees belong. 

 At p. iv of my " Introduction " I have given, also on the authority of Mr. Davis, 

 a section of the beds between the Elland Flagstones and the " Rough Rock " 

 or Millstone Grit. The present section shows the upward continuation of the same 

 series of beds, with a few observations in reference to them. 



Clifton or Oakenshaw Eock 





SO 







Shales (with 80 yards Band Coal) 



180 







Shales with Stone and Coal 





70 







Hard-bed Band Coal 



1 



2 



Crow Coal with partings 





7 



6 



Shales (with 36 yards Band Coal) 



137 







Shales with Ironstone (Low 



Moor) 



36 







Hard-bed Coal (Ganister) 



2 



2 



Elack-bed Coal . 





2 



6 



Shale, &c. 



29 



6 



Measures . 





130 







Middle Band or Clay Coal 







6 



Better-bed Coal . 





1 



6 



Stone and Shale . 



62 







Shales 





54 







Soft-bed Coal 



1 



6 



Elland Flagstone- — a. Flags 





30 







Shales . ... 



102 







b. Shale 





35 







Coal and Seat Earth 



5 



6 



c. Flags 



. 120 tc 



> 180 







Eough Eock 







" The Elland Flag rock is of great thickness, and forms a bold range of hills from 

 Sheffield and Wadsley, northwards to Penistone, west of Huddersfield, south and 

 east of Halifax to north of Leeds. In Lancashire it is the Rochdale and Upholland 

 Flags ; probably when deposited it covered an area of 1500 square miles, and it is 

 the thickest and most persistent of the Coal Measures sandstones. 



1 The note on the previous page shows that the root terminated in an absolute point. 



