574 



MR ROBERT KIDSTON ON 



in the Upper Coal Measures : of these, 8 are characteristic of that horizon ; 24 are met 

 with in the Middle Coal Measures, of which 5 are characteristic of that horizon ; 15 

 are found in the Lower Coal Measures, 8 of these being common to all the divisions of 

 the Coal Measures. 



There is, therefore, in the Lower Pennant Series an admixture of plants, some 

 of which may be regarded as Upper Coal Measure forms, while there is a number 

 of species which may be looked upon as Middle Coal Measure plants. The Lower 

 Pennant Series can therefore only be regarded as a Transition Series, connecting the 

 Upper Pennant ( = Upper Coal Measures) with the White Ash Series, which will 

 presently be seen to be of Middle Coal Measure age. 



Such Transition Series are very rare in the Carboniferous of Britain and in other 



Coal Fields (with the exception of the Somerset Coal Field, which will be referred to 



presently), where more than one of the divisions of the Coal Measures occur, the different 



divisions are more sharply marked off, — showing that in these areas the Transition Beds 



had either never existed, or if formed, removed before the deposition of the succeeding 



series. 



Table III. 



Comparative Table of the Fossil Plants of the WJiite Ash Series, South Wales Coal 

 Field, with those of the Upper, Middle, and Lower Coal Measures. 







CO 



5 v 



CO 



cd cd 



CO 





CD "£ 



g<§ 



73 *3 



5: 8 





S<» 



t> "c3 



s^ 



1-4 a 





£ 



o 



>=« o 



o 





o 



o 



o 



Calamitina Gopperti, Ett., sp., . 



1 





X 





„ varians, Stbg., sp., 













X 



X 



X 



X 



„ undulatus, Stbg., sp., . 













X 





X 



X 



Catamites ramosus, Artis, sp., 













X 



X 



X 



X 



,, Suckoioii, Bgt., . 













X 



X 



X 



X 



Calamodadus eharaiformis, Stbg., sp., 













X 





X 



X 



„ equisetiformis, Schl., sp., 













X 



X 



X 



X 



„ lonyifolius, Stbg., sp., 













X 





X 



X 



Calamosfar.hys typica, Schimper (in part), 













X 





X 



X 



Splienopteris obtusiloba, Bgt., 













X 





X 



X 



,, trifoliolata, Artis, sp., 













X 





X 



X 



„ dilatafa, L. and H., . 













X 





X 





,, Conwayi, L. and H., 













X 









Corynepjteris (Sjih.) mralloides, Gutb., sp., 













X 





X 





EivmojiteriH aiieiirisitt'folia, Stbg., sp., 













X 





X 



X 



Neuropteris heterophylla, Bgt., 













X 





X 



X 



,, rarinervis, Bunbury, . 













X 



X 



X 





,, tenuifolia, Schl., sp., . 













X 





X 





,, gigantea, Stbg., 













X 





X 



X 



,, osmundce, Artis, sp., . 













X 





X 





Mariopteris muricata, Schl., sp., . 













X 



X 



X 



X 



I', r,, r l, ,■;,-, Mill, mi, Artis, sp., 













X 



X 



X 



X 



Alethcqderis lonchitica, Schl., sp., . 













X 



X 



X 



X 



,, ilcnirmiH, Artis, sp., . 













X 





X 



X 



„ Davreuxi, Bgt., . 













X 



X 



X 





L'mrln>j>ff'rix ru.yoxa, I!gt., 













X 





X 





SphenophyUum cuneifolmm, Stbg., sp., 













X 





X 



X 



„ myriophyllum, Crepin, 













X 





X 



X 



