546 MR. T. C. CANTRILL OK SPIRORBIS -LIMESTONE, ETC., [Aug. 1895, 



So far as we at present know, the case seems to stand as 

 follows : — The Calcareous Conglomerates and Trappoid Breccia of 

 the Middle Group are variable in thickness and horizontal extent, 

 and in some cases altogether disappear. With regard to the Upper 

 Sandstones and Marls, which may be seen at various points between 

 Enville and Claverley where not concealed beneath drift, we must 

 be more cautious. It has been stated that they differ in no essential 

 respect from the Lower Sandstones and Marls. "We have already 

 (p. 540) seen that there is good evidence for the occurrence therein 

 of thin coals. But an examination of the exposures along the 

 course of Philley Brook leads me to believe that these beds show a 

 much closer general affinity to the overlying Lower Bunter than do 

 the Lower Sandstones and Marls. 



However, accepting the evidence for the coals at White Cross, 

 the conclusion seems to be inevitable, that whatever position we 

 assign to these ' Permian ' beds, we mui=t treat the whole series as an 

 individual group ; and whatever name we give to the Lower Sand- 

 stones and Marls, we must also give to the Conglomerate and Breccia 

 Group, and to the Tipper Sandstones and Marls. 



We have next to consider whether they should be regarded as : — 



1. Bed Upper Coal Measures. 



2. Bothliegende or Lower Permian. 



3. Passage Beds from Upper Coal Measures to New Bed 



Sandstone (=true Permian and Trias). 



Judging by precedent, they may well be called ' Bed Upper Coal 

 Measures.' But perhaps we are not entitled to entirely neglect the 

 one great fact of their constituting a practically unbroken red series 

 1500 feet thick. Were it not for the presence of /Sp'ro^'s-limestone 

 and thin coals, and if there were a more pronounced break at the 

 base of the series — if, moreover, we could get rid of the evidence of 

 the fossil flora obtained from the same series at Hamstead and 

 Sandwell in South Staffordshire — we might well retain the old name 

 of ' Lower Permian ' or Bothliegende. 



In the light of the evidence herein described, however, we cannot 

 fail to see that in the Wyre Porest district, at least, the conditions 

 which prevailed during the period of the Yellow Upper Coal Mea- 

 sures — while sandstones, shales, pyritous coals, and Sjnrorbis- 

 limestones were deposited — continued with little interruption, but 

 with a gradual change, till the advent of the Trias. This gradual 

 change is marked by the diminution in the number and thickness, 

 and ultimate cessation of the coal-seams, and the cessation, after a 

 while, of the formation of Spirorbis-liraestojies. At the same time, 

 the change in colour was possibly caused by the closing of the area 

 of deposit, although this closing did not at once prove fatal to the 

 Spirorbis, which flourished and formed a limestone, in spite of the 

 changed conditions, at least 200 or 300 feet above the base of the 

 red rocks. 



