364 PROCEEDINGS OF TIIE GEOLOGICAL SOCIETY. [Apr. 22, 



author, or what I call the Lower Llandeilo series. This Primordial 

 zone is overlain by dark flinty slate and lydianstone (/), full of 

 Graptolites ; and in the Eichelberg these again underlie glossy clay- 

 slates of greenish-grey colour (g), with Nereites and Tentaculites. 

 Finally, the true Devonian limestones (h) (the concretionary Cy- 

 pridina-limestones, so well seen in the environs of Saalfeld, i.e. the 

 Clymenia-limestone of Miinster, or this younger formation) under- 

 lie all the older Silurian series. 



With this highly-inverted region around Hof I was already 

 acquainted in previous years. In fact, I had abandoned all idea of 

 eliciting the order of superposition, and of assigning to the beds their 

 proper places in the succession by the fossils they respectively con- 

 tained. My associates may therefore well imagine what great value I 

 attach to the investigations of M.Giimbel,whohas so effectually cleared 

 away the remainder of the obscurity in which this tract was shrouded, 

 and has given to the fossiliferous deposits such clear base-lines. 



The Silurian RocJcs of Bohemia. — Having now described the re- 

 gular ascending succession of the Palaeozoic rocks of Bavaria, in the 

 environs of Hof, as well as their inversion, let us traverse the great 

 region of crystalline rocks which separates them from that cele- 

 brated Silurian basin of Bohemia, so well described by M. Barrande 

 in his truly classical work. 



I have already alluded to the wide extension of the so-called Ur- 

 thon-Schiefer, or primary clay-slate, which subtends this basin on 

 the west; andM. Barrande has, indeed, clearly shown how in other 

 parts, particularly near Przibram, the fossiliferous primary zone is 

 equally supported by unfossiliferous schists and grauwacke, and his 

 still older " roches azoiques." 



Knowing that the Austrian Surveyors had prepared, and were 

 about to issue, their geological maps of this region, the eastern parts 

 of which only I had several times visited, in company with my 

 friend M. Barrande, I naturally felt a great desire to see how the 

 lower members of his series were related to the still older rocks on 

 the western flank of the basin — a tract which I had never seen. I 

 also knew that from this western side a new railroad had been cut, 

 which, in proceeding from Pilsen to Prague, laid open several of 

 the Silurian rocks. In sending to me the new Austrian maps at 

 Marienbad, M. Haidinger also stated that he had requested M. Li- 

 poid, who had coloured the sheets in question, to meet me at Pilsen. 

 I had, indeed, previously made the acquaintance in London of a very 

 intelligent Bohemian naturalist and palaeontologist, Dr. AntonFritsch, 

 the Curator of the Natural History Museum at Prague, who attended 

 the recent International Exhibition in London, and this gentleman 

 (M. Barrande being then absent from Prague) agreed to meet me 

 at Pilsen, accompanied by M. Lipoid, the Austrian Surveyor. 



Aware that the subject of the " Colonies " had been so criticised 

 as to cause my eminent friend to bring out replies in defence of his 

 views, I explicitly told the gentlemen who accompanied me in my 

 rapid journey from Pilsen to Prague, that the subject of the " Colo- 

 nies" could form no part of my observations, stating truly that. 



