and the Pal(Bozoic System of England. 365 



apparent passage into the Tilestone) is defective at its base ; (2) 

 that on British evidence (the only evidence here considered) we 

 cannot unite together the great groups of Devonshire^ Here- 

 fordshire, and Scotland, so as to form one connected and un- 

 broken series, to be linked, in ascending numerical order, to the 

 upper groups of the Lower Palaeozoic division. 



III. Upper Palceozoic Division. 



Coal-fieldof the basin of the Tweed, and lower coal-field of Scotland. 

 [Under this group may, perhaps, be finally arranged the " carboni- 

 ferous slates" of Ireland, and, perhaps, the Marwood andPetherwin 

 groups above mentioned. The coal-field of the Tweed appears to 



2 '{ include the " great scar-limestone " of Derbyshire and Yorkshire.] 



2. " Limestone shale " of Derbyshire, " Yordale series " of Phillips. 



3. Mill-stone grit. 



4. Great upper coal-field of England, to be divided into two or three 



sub-groups. 



Upper Division continued. 



5. Coarse red sandstone and conglomerate, generally unconformable 

 to the carboniferous strata. It contains (though rarely) true car- 

 boniferous fossils {Lepidodendra, StigmaricB, &c.), which may, 

 perhaps, have been drifted mechanically out of the contiguous 

 coal-fields into this coarse, overlying Permian sandstone. 



3. Marl-slate and their bedded compact limestone ; a few impres- 

 sions of plants; shells of palaeozoic genera.— Producta, Spirifer, 

 &c. ; many impressions of fishes — Falceoniscus, Flatysomus, 

 Pygopterus, Acrolepis, &c. 

 •^ 7. Magnesian limestone, in some parts of the north of England of 

 great thickness, and most complicated structure : e. g. rarely a 

 crystalline dolomite, compact, cellular, earthy, brecciated, globu- 

 lar, oolitic, &c., occasionally with organic remains — Producta, 

 Spirifer, Synocladia, Fenestella, &c. 



8. Red gypseous marls, very slightly saliferous. 



9. Thin-bedded gray limestone, sometimes cellular and dolomitic. A 

 few traces of bivalves, &c. 



10. Red gypseous marls. [The above series is overlaid by the great 

 red and variegated sandstone which forms the base of the Trias.l 



The preceding ten groups are derived from the sections of 

 Yorkshire and Durham, where the series is best developed *. 



In the south of England the whole series is sometimes repre- 

 sented by a mass of conglomerate. In central England, War- 

 wickshire, &c. it is represented by a coarse red sandstone, some 

 beds of which become calcareous ; and the whole group is con- 



* It is evident from the description of these groups, as well as from 

 their general want of conformity to the carboniferous groups, that the 

 Permian series of England is physically more nearly connected with the 

 triassic than with the palaeozoic rocks. But its fossils are of a decided 

 palaeozoic type. If we adopt the term Permian as a general designation 

 of the series, it must be done with proper limitations derived from the 

 English types. For to class under the palaeozoic name, Permian, the red 

 sandstone of St. Bee's Head, or the great red sandstone of central England, 

 would, I think, be perfectly erroneous. 



