﻿Vol. 6 1.] UPPEK PORTION OF THE COAL-MEASURES. 309 



Messrs. F. Gr. Meachem & H. Insley had previously referred these 

 rocks to the Upper Coal-Measures. 1 I shall have occasion to refer 

 to the Upper Coal-Measures of Great Barr later on in this paper. 



The dividing-line between the Upper and Middle Coal-Measures, 

 adopted in the Potteries Coalfield, was a Sjjirorbis -Limestone, 

 12 yards above the Bassey-Mine Ironstone. 



From the entire series of rocks above this line, the only plants met 

 with up to the time mentioned above were : — 



Pecopteris arbor escens (Schl.). 

 Pecopteris cyathea (Schl.). 

 Mariopteris muricata (Schl.). 

 Alethopteris aquilina (Schl.). 

 Alethopteris lonchitica (Schl.). 

 Odontoptosis sp. 

 Neuropteris ovata, Hoffm. 



Catamites Sicckowi, Brongn. 

 Calamocladus equisetiformis (Schl.). 

 Lepidostrobus variabilis, L. & H. 

 Sigillaria Brardi, Brongn. 

 Stigmaria ficoides (Sternb.). 

 Bhabdocarpus sulcatus (Presl). 



The whole of these species, except Rhabdocarpus sulcatus, occur 

 in the Upper Coal-Measures, though some are very rare therein, and 

 several of the plants are much commoner in the Middle and Lower 

 Coal-Measures. 



When dealing with the general classification of the British 

 Carboniferous rocks as determined by their fossil plants,' 2 1 mentioned 

 that Dr. Wheelton Hind 3 had discovered, in rocks a few yards 

 above the Spirorbis- Limestone, specimens of Neuropteris 

 gigantea, Sternb., N. heterophylla, Brongn., and Splienopliyllum 

 emarginatum, Brongn., and, at a later date, Sigillaria ovata, 

 Sauveur. 4 



Of these, the only one known to occur in the Upper Coal-Measures 

 was Sphenophyllum emarginatum, and of the other three, Sigillaria 

 ovata was a typical Middle Coal-Measure species, while the two 

 Neuropterids were common to both the Middle and Lower Coal- 

 Measures 5 ; it was therefore evident that the lower part, at least, 

 of the group which had been referred to the Upper Coal-Measures 

 belonged to my Transition Series, a division that I had 

 proposed for certain beds lying between the Middle and the Upper 

 Coal-Measures, and the flora of which was characterized by an 

 admixture of Upper and Middle Coal-Measure species. This series 

 forms a most natural and important group. When preparing the 

 * Additional Records & Notes ' (op. cit. p. 129), in referring to 

 this Transition Series, I said : — 



' This series appears to be very feebly developed in the Potteries Coalfield, 

 though it may form a more important group than is at present suspected.' 



This suggested possibility has proved to be the case, and the rocks 



1 Rep. Brit. Assoc. 1886 (Birmingham) p. 626. 



2 ' On the Various Divisions of British Carboniferous Rocks, as determined by 

 their Fossil Flora ' Proc. Roy. Phys. Soc. Edin. vol. xii (1893-94) pp. 183-257. 



3 Op. cit. p. 229. 



4 ' Additional Records & Notes on the Fossil Flora of the Potteries Coal- 

 field, North Staffordshire' Trans. North Staffs. Field-Club, vol. xxxi (1897) 

 p. 127. 



5 A single example of Neuropteris heterophylla has quite recently been found 

 in the ' Keele Group ' — Upper Coal-Measures. 



Q. J. G. S. No. 242. y 



