1855.] MURCHISON AND MORRIS THURINGERWALD. 427 



eluded his memoir with a valuable table, in which all the species 

 of plants from Algae to Coniferse, and of animals from Zoophytes 

 through Molluscs and Crustaceans to Fishes and Reptiles, which are 

 common to Germany, Great Britain, and Russia, are specially marked. 

 By this comparison we learn, that out of one hundred and thirty- 

 eight species known in Germany, sixty-nine or one half are Biitish 

 forms ; twenty of these German species being found in those vast 

 eastern provinces of Russia, whence the name of Permian was derived. 

 In short, we see in the Permian that which is common in our own 

 Isles throughout the palaeozoic rocks, and on which we have pre- 

 viously dwelt, viz. that each natural group is characterized by a cen- 

 tral mass of limestone, in which the fossils prevail, and from which 

 they diminish upwards and downwards as the rocks pass into sands, 

 shale, or other strata void of or slightly charged only with calcareous 

 matter. 



In the Permian rocks, then, of the Thiiringerwald and other parts 

 of Germany, we consider the Zechstein to be their calcareous centre ; 

 for the sera of the Rothe-todte-liegende was, on the whole, too turbu- 

 lent and its sediments too much charged with iron oxides to lead us 

 to look in them for aay good examples of organic remains. In fact, 

 a very few fragments of plants, including the well-known stems of 

 Ferns called Psaronites, are all that we usually detect in the deposit, 

 though in certain localities where the physical conditions have been 

 favourable, as in the clay stone between the conglomerates in the 

 environs of Zwickau and in two or three spots in Saxony, an abundant 

 flora has rewarded the researches of Colonel Gutbier *. 



Now, in Russia, the physical conditions do not exist which in 

 Germany satisfactorily account for the restriction of the fossils to one 

 calcareous zone. In the first place, there is no great coarse conglo- 

 merate or trappoid breccia beneath the limestones, but simply some 

 grits and sandstones with plants, &c. Again, the calcareous matter, 

 instead of being confined to one zone, reoccurs even in the form of 

 limestone at several levels (bands of red and variegated sandstone 

 being interlaminated), whilst the whole of the limestone is crowned by 

 coarse conglomerates and sandstones infinitely more resembling the 

 Rothe-todte-liegende than any of the subjacent strata. It is in this 

 upper band that the remains of reptiles belonging to the group of 

 Protorosauri have been found, which in Germany is found beneath 

 the limestone. It is, indeed, in these overlying sandstones and con- 

 glomerates that most of the plants of the Permian or quasi-Carbo- 

 niferous type occur, the same upper zone being also that which is so 

 extensively charged with copper ore, that mineral being in Germany 

 invariably beneath the limestones. 



From these evidences, therefore, which are positive, and are not 

 discountenanced by any data in Germany, we adhere to the classifica- 

 tion of the Permian group as originally defined by Murchison and his 

 associates De Verneuil and Keyserling. 



* Out of sixty species of these Permian plants, forty are peculiarly Permian, 

 and of these several are identical with forms brought from strata which lie above 

 all the Zechstein bands in Russia. See Verst. Perm. Systm. in Sachsen, Heft 2. 



VOL. XI. PART I. 2 G 



