26 D. C. DAVIES ON THE UPPER CARBONIFEROUS 



stratified with red shales to the thickness of 220 feet, resting upon 

 the /SJpiror&is-limestone, and how in this respect it compares with 

 the sections of Canobie, Ardwick, Patricroft, Alberbury, "Warwickshire, 

 Staffordshire, and Nova Scotia. 



The section commences therefore at more than the average height 

 above the Spirorb is-limestone at which Permian strata are usually 

 made to begin in English sections. 



In group 2, or the lowest usual division of Permian strata, we see 

 how it contains in its breccias, its green, grey, red, and brown sand- 

 stones, as well as in its drifted plant-remains, all the varied phases 

 of the group over the wide range embraced by the sections. 



In group 3 (middle Permian) this resemblance is also very great. 

 There are the ever present red, white, yellow, and variegated marls ; 

 then in the calcareous bands interstratified with those marls, in the 

 rolled and nodular limestones under the Morlas main-coal, in the 25 

 per cent of carbonate of lime contained in the pyrites of that coal- 

 seam, in the limestone masses of the Coedyrallt rock, as well as in 

 the bedded calcareous concretions of that rock, we have, I think, un- 

 mistakably the equivalent of the more massive limestones of the 

 north-east, the "brockrams" of the north-west, the thin limestones 

 of Lancashire, and the calcareous conglomerate of the West Midlands, 

 as well as of the representatives of these in Ilussia, Saxony, Bohemia, 

 and Nova Scotia. 



I now approach that development of coal-measures in the upper 

 part of group 3 of the Ifton section (No. 11) which, to some minds, 

 will form a strong objection to the acceptance of these beds as 

 equivalents of Permian strata. But why ? We see how these beds 

 are paralleled by the dark fossiliferous shales of Eden, by the dark 

 shales of Bohemia, and by shales and coal in Nova Scotia. A com- 

 parison of the list of fossil plants found at Ifton with that given 

 by Murchison and Harkness, and hy Mr. Dawson, in the papers already 

 referred to, and of all these with lists from the continent of Europe, 

 will show a family likeness running through the whole, and will 

 further show how in all those widely distant localities the same new 

 forms appeared in the midst of the survivors of the older Carboni- 

 ferous flora. 



The uppermost sandstones, group 4, by their colour, massiveness, 

 homogeneity, and mineral composition, correspond to the uppermost 

 sandstones of the same group wherever these are developed ; while 

 they do not correspond to, or contain within them the representatives 

 of the groups below them. Besides, as I have pointed out, they may 

 be traced at intervals until they are seen lying above the calcareous 

 conglomerate at Alberbury. Their place, therefore, at the summit, 

 and not at the base, of the Permian strata is clearly proved. 



The conclusion is therefore to me inevitable, that, in their strati- 

 graphical position, their mechanical arrangement, their fossil remains, 

 and in their mineral composition, the strata of groups 2 and 3 of the 

 Ifton section (No. 11) are the equivalents of the middle and lower 

 divisions of the strata usually described as Permian in this and other 

 countries. 



