220 Proceedings of the Royal Physical Society. 



The coal and subordinate strata extend as a narrow band 

 from Vatersteine, behind the old castle of Hohenstein, to 

 Neustadt, then onwards by Ilfeld across the Behrethal to 

 the Kunzenthal, near Eothensiitte — a total distance of some 

 16 miles. The series, which dips away from the mountains, 

 thus lies in a great bay in the old " core " rocks, which have 

 here formed part of the ancient margin of the Carboni- 

 ferous sea. 



The flora of this district is characterised by the abundance 

 of its ferns, which leads to its being correlated with the 

 highest of the German coal strata. Forty-six species of 

 plants are known to occur at Ilfeld. A list of the flora 

 is given in the article in the Colliery Guardian just 

 referred to. 



e. Permian {Dyas). 



The strata above the coal-seam are at some places uncon- 

 formable, and contain a slightly different flora from that 

 which is furnished by the bituminous shales associated with 

 the coal itself The division is, however, by no means very 

 sharply defined ; but Murchison, Sedgwick, and F. A. Eoemer 

 of Clausthal were of the opinion that the coal-seam is of 

 Carboniferous age, while all the overlying red rocks belong 

 to the Lower Permian or Eothliegendes group, and most 

 geologists are inclined to adhere to their views. 



The strata above the coal, which are of no great thickness, 

 are covered by a thick bed of basalt, over which comes a 

 series of variegated shales and sandstones, reaching occa- 

 sionally a thickness of 100 feet, and containing the Permian 

 plants Walchia piniformis and Odontopteris oUusilola. These 

 beds are in turn overlaid by a great bank of interbedded 

 porphyrites, which at Ilfeld represent the whole of the Lower 

 Eothliegendes series. The porphyrites are red and amygda- 

 loidal, and often very much decomposed. 



At Ilfeld the remainder of the Eothliegendes is occupied 

 by sandstones, tuffs, and conglomerates, which have generally 

 the red hue characteristic of the series, but become grey 

 towards the base of the Zechstein. 



