THE FOSSIL FLOEA OF THE SOUTH WALES COAL FIELD. 



575 



Table III. — continued. 





OJ 

 <) ID 



03 



03 



3 .5 





+2 s- 





33 



Is 







t3 'tS 



^1 



hJ "d 





£ 



6 



O 



6 



Lepidodendron longifolium, Bgt., . 



X 









„ opliiurus, Bgt., 













X 





X 



X 



„ obovatum, Stbg., 













X 





X 



X 



„ aculeatum, Stbg., . 













X 



X 



X 



X 



Lepidostrobus laneeolatus, L. and H., sp., 













X 





X 



X 



„ triangularis, Zeiller, sp., 













X 





X 





LepidopMoios laricinus, Stbg., 













X 





X 





„ aeerosus, L. and H., sp., 













X 





X 



X 



Bothrodendron punetatum, L. and H., 













X 





X 



X 



Sigillaria eamptotamia, Wood, sp., 













X 



X 



X 



X 



„ mamillaris, Bgt., 













X 





X 



X 



„ laevigata, Bgt., . 













X 



X 



X 





,, elongata, Bgt., . 













X 





X 





„ tessellata, Bgt., . 













X 



X 



X 



X 



„ discophora, Bgt., 













X 



X 



X 



X 



Stigmaria ficoides, Stbg., sp., 













X 



X 



X 



X 



Cordaites principalis, Germar, sp., 













X 





X 



X 



Pinnularia capillacea, L. and H., . 











X 





X 



X 



Analysis of Table III. 



A much larger collection of fossil plants has been made from the White Ash Series 

 than from either of the preceding Series. This probably results more from the greater 

 prevalence of sandstone beds in the two upper series ; but when shale beds are met with, 

 fossil plants are generally found. In the White Ash Series, on the other hand, shales 

 much predominate over sandstone beds. 



In all, omitting one record of which the horizon is doubtful, 45 species are recorded 

 from the Wliite Ash Series, of which 2 have as yet only been found in these rocks in 

 Britain. Of these 45 species, 15 are found in the Upper Coal Measures, but all of 

 these are also common to the Middle Coal Measures. Forty-four are found in the 

 Middle Coal Measures, and 32 occur in the Lower Coal Measures, but all these are 

 also found in the Middle Coal Measures. It is therefore seen, if we except the two 

 species hitherto only found in Britain in the White Ash Series, that all the others are 

 known Middle Coal Measure plants, and therefore the White Ash Series must be 

 regarded as of typical Middle Coal Measure Age. 



To sum up, the correlation of the three divisions of the South "Wales Coal Field is 

 shown in the following table. 



I. Upper Pennant Series = Upper Coal Measures of Britain. 

 II. Lower Pennant Series — Transition Series — intermediate in character, between 



the Upper and Middle Coal Measures. 

 III. White Ash Series = Middle Coal Measures. 



