Vol. 69.] THE PEMBROKESHIRE COALFIELD. 273 



Lower Pennant of the main portion of the South Wales Coalfield 

 has been shown by Dr. Kidston to be a true Transition Coal- 

 Measure flora. A comparison of the two floras, however, shows 

 that all the species occurring in the Lower Pennant which are 

 Upper Coal-Measure forms, are absent from the 'Pennant Grit' 

 of Pembrokeshire, thus confirming the conclusions which were 

 arrived at above. These Upper Coal-Measure plants are : — 



Annularia stellata (Schloth.). J Nctoroptf.ris ovata Hoffm. 1 



S-phcnophyllum emarginatum Brongn. Odontopteris luidlcyana Sternb. 



Sphenoptcris neuropteroides (Boulay). ' Lepidodendron dichotomum Zeiller. 



Neuropteris flexuosa Brongn. j Cordaites angulostriatus Grand 'Eury. 



Neuropteris macrophylla Brongn. ' 



These have not been obtained from Pembrokeshire. 



There are also at least nineteen species which have been recorded 

 from the Lower Pennant of the main portion of the South Wales 

 Coalfield, but have not been obtained from the ' Pennant Grit ' of 

 Pembrokeshire. 



There are, in fact, only nine 2 species known in common to the two 

 series. Calamocladus equisetiformis (Schloth.) is recorded from the 

 Lower Pennant of South Wales, but is only a doubtful determination 

 from the ' Pennant Grit ' of Pembrokeshire. 



Further, there are twenty-one or twenty-two Pembrokeshire 

 species which are unknown from the Lower Pennant of the main 

 portion of the South Wales Coalfield. 



It is obvious, therefore, that there is a considerable difference 

 between the fossil floras of the ' Pennant Grit ' of Pembrokeshire 

 and the Lower Pennant of the main part of the South Wales Coal- 

 field, even though most of the species which are recorded from the 

 latter are plants which occur in the Middle Coal Measures. 



(b) The Fossil Floras of the Lower Coal Series, including 

 that of the i Pennant Grit/ of Pembrokeshire and the 

 White Ash Series of South Wales. 



The fossil plants of the Lower Coal Series of Pembrokeshire, 

 including those of the ' Pennant Grit,' can be more exactly 

 compared with those recorded from the White Ash Series, or Lower 

 Coal Series, of the main portion of the South Wales Coalfield : 

 for all belong to the Middle Coal-Measure horizon. 



There are, however, at least twenty-five species which have been 

 recorded from the White Ash Series, but have not been obtained 

 from the Lower Coal Series, or the ' Pennant Grit,' of Pem- 

 brokeshire. 



Twenty species are common to the Lower Coal Series, including 

 the ' Pennant Grit,' of Pembrokeshire, and the White Ash Series. 



1 Recorded by Mr. E. E. L. Dixon. See Strahan (1907) p. 156. 



2 Two of these have been recorded from the Pennant Series of the main 

 part of the South Wales Coalfield by Mr. E. E. L. Dixon. See Strahan (1907) 

 p. 156. 



