1863.] aiURCHISON BAVARIA A.ND BOHEMIA. 355 



recently published geological maps of Germany, M. Ludwig had 

 marked the Palaeozoic subdivisions as Silurian, Devonian, Carboni- 

 ferous, and Permian*. 



Thus, in travelling to the baths of Marienbad, I perceived that on 

 the western flank of the crystalline rocks of Eastern Bohemia and 

 the Erzgebirge the author had thus named and delineated the three 

 oldest of these groups in the tract around Hof, where, when I first 

 explored it, " grauwacke" only was applied to the whole region by 

 German authorities. 



It was, indeed, in the year 1839 that Professor Sedgwick and 

 myself began to make the subdivision, by pointing out the existence 

 of both Devonian and Carboniferous limestones near Hof. In sub- 

 sequent years, with the good maps of ISTaumann, I tracked Silurian 

 rocks, with Graptolites, as separated from Devonian limestones, ex- 

 tending from the Erankenwald into the Thiiringerwald, where certain 

 meagre representatives of the Upper Carboniferous rocks are sur- 

 mounted by a full Permian series . 



Proceeding from Eisenach on the north-west, where the great 

 Palaeozoic promontory of the Thiiringerwald terminates in a point, 

 we see, in advancing to the south-east, that these Palaeozoic rocks 

 gradually expand, until, in the latitude of Hof, they occupy a great 

 width, and are succeeded on the south-east by the inferior azoic 

 and crystalline rocks of the Eichtelgebirge and the broad tracts of 

 eastern Bohemia. 



To the south-east of Hof, M. Giimbel, of Munich, has recently 

 made a most important discovery. In schists overlying primary 

 clay-slate, and underlying Silurian rocks with Graptolites, he found 

 a peculiar fossiliferous band, the Trilobites of which, having been 

 transmitted to M. Barrande, were determined by his authority to be 

 ConocepliaM, OIeni,ajidEllipsocejphali, associated with Cystidece, Orthis, 

 Discina, and Puginnculus. Hence it was clear that M. Giimbel had 

 discovered in Bavaria an equivalent of the Primordial zone of the 

 Silurian series, of which M. Barrande had been the discoverer in his 

 Silurian basin of Prague. We thus learn that the Silurian rocks of 

 Bavaria, however less rich in fossils in their central and upper 

 members than those of the Bohemian basin of Prague, have the same 

 Trilobite -bearing base as the latter. 



Having myself passed over the tract occupied by the older rocks 

 which separate those two Palaeozoic tracts, I became very desirous of 

 obtaining from M. Giimbel some account of the exact order, as well 

 as of the dimensions, of those inferior rocks on which the Palaeozoic 

 rocks repose. As he has been so kind as to send me a sketch-map 

 of all the region (fig. 1), as well as a transverse section (figs. 2 & 3), 

 showing the succession from the Carboniferous Limestone of Hof, 

 down to the gneiss and granite of the Fichtelgebirge near Selb, I 



* See Ludwig's ' Deutschland,' 1860, and ' Deutschland und das Alpen- 

 Gebiet,' and compare them with von Dechen's Geological Map of Germany, 

 published in 1838, in which the vast tracts now so subdivided were, as re- 

 gards the three lower formations, as well as the inferior clay-slate, all grouped 

 under one colour and with the name of ' Grauwacke.' 



