304 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Mar. 4, 



characteristic fossil Permian plants, such as the typical Psaronites 

 and Araucarites, Gugliehnites Permianus, Gein., Aleifwpteris pris- 

 matifolia, Gein., Walchia pisiformis, Sigillaria Danziana, Gein., 

 Noeggerathia, and Neuropteris of peculiar species, are all plants of 

 this particular period, and differ essentially from those of the Car- 

 boniferous age. 



Concluding General Observations. — Though it is out of my power 

 to make a correct estimate of the thickness of the strata exposed in 

 the section above described, yet, as the distance from a mile south 

 of Liebestadtl, where the upper beds have already a dip to the S.S.E., 

 to a spot north of Semil, where the conglomerates or *bottom-beds 

 of the series still dip in the same direction at an average angle of 

 about 10° to 15°, is about five or six miles, we cannot but assign 

 a vast thickness to these deposits, even allowing for a certain 

 amount of undulation and repetition in the central part of the 

 section. For in this case the succession is not only one of beds 

 of red sandstone and pebble-beds with porphyries, such as the geolo- 

 gists of North Germany have hitherto regarded as the Roth-liegende, 

 but it consists of diversified alternations of sands, marls, bituminous 

 shales, copper-schists, limestone, hard and soft sandstones, and con- 

 glomerates, with interpolated porphyries and other igneous rocks. 



Any doubt which might have existed as to the thickness of the 

 whole, as derived from a transverse section like the preceding made 

 across the strata which are successively exposed at the surface, has, 

 however, been set aside in other places where no such great variety 

 in the strata occurs. Thus, near Eisenach, in the borings alluded to 

 in former communications, 2600 feet of sandstone and conglomerate- 

 beds were passed through in search of coal*. Recently, indeed, still 

 more satisfactory evidence has been transmitted to me by Professor 

 Naumann of Leipzig, who is about to bring out a work descriptive 

 of the two great divisions into which he separates the Roth-liegende 

 or Lower Permian of Saxony. His upper division, of considerable 

 dimensions, consists of schistose red clay and marl, sandstone, and 

 fine conglomerate. A shaft has actually been sunk at Erlbach 

 through 2200 feet of the lower Roth-liegende only, with its con- 

 glomerates and interstratified porphyries, claystone, and tuffs. 



At that depth of 2200 feet true Carboniferous strata were indeed 

 reached ; but by the last accounts no bed of coal had been found in 

 them, though the Carboniferous formation had been penetrated to the 

 additional depth of 400 feet, making the total depth of the pit 2600 feet. 



After this last-mentioned positive evidence of the order of super- 

 position, showing that the lowest member of the Permian rests un- 

 conformably on subjacent Carboniferous strata, coupled as the fact is 

 with the demonstration of Professors Goppert and Geinitz that the 

 fossil flora of these beds is distinct from that of the Coal-period, and 

 also with the physical proofs brought forward by Geinitz as to the 

 clear and unconformable separation of the two, it is to be hoped that 

 my able contemporary, M. Beyrich, will no longer class the Roth- 

 liegende with Carboniferous deposits. 



* See » Siluria,' 2nd edit., p. 333. 



