Geological Society. 



south-eastern and south-western boundaries of Bohemia, he proceeds 

 to the main object of the memoir. The district described by Mr. 

 Ansted is included within a triangle, having the country between 

 Luditz and Pilsen for a base, and Prague for its apex ; and its struc- 

 ture is explained by a series of sections from Luditz to Pilsen 

 Radnitz to Rakonitz Zebrak to Ginetz and Przilep to Karlstein, 

 all of them being more or less in the dip of the strata. The formations 

 composing the district, are granite, gneiss, graywacke, coal mea- 

 sures, trap rocks and accumulations of superficial debris. It is stated 

 that a line drawn from Eger on the west to Prague on the east 

 would completely separate the sedimentary deposits of a newer date 

 than the carboniferous system from the coal measures and transi- 

 tion rocks ; and that the latter occur only to the south of the line. 

 Near Eger is a small local deposit of upper tertiary sandstone, men- 

 tioned by Mr. Ansted on account of its containing myriads of fossil 

 infusoria cases. 



Section 1. Luditz to Pilsen. Luditz stands upon a range of round 

 topped gneiss hills, but in a depression between two of them ; and 

 about 3 miles from the town, is a bed of thinly laminated micaceous 

 sandstone, containing a few obscure vegetable markings, and believed 

 by Mr. Ansted to be a recent deposit. Proceeding in the direction 

 of Pilsen, the gneiss is succeeded by a hard cherty stone, considered 

 by the author to belong to a rock which underlies the coal mea- 

 sures in other parts of the country, but to have been protruded at 

 this point by igneous agency. The next hill is formed of trap, and 

 beyond it, is a bed of similar cherty sandstone, covered up towards 

 the S.E. by the red conglomerate on which Manotin is built. To 

 the south of this town, slate rocks are finely developed for several 

 miles, forming precipitous cliffs, with the strata dipping to the S.E. 

 They are covered in part by gravel, and are succeeded by rotten 

 shales, assigned by Mr. Ansted to the graywacke system. These shales 

 are visible for only a short distance, being superficially replaced by 

 a thick covering of gravel, which extends for ten miles. At the end 

 of that distance, hills of sandstone commence, and contain near 

 Pilsen workable seams of coal. The sandstone is coarsely grained 

 and not very coherent ; and the coal bands, which are accompanied 

 by shales, are of variable thickness. The dip is very small, and to the 

 S.E., but the stratification is totally unconformable with the gray- 

 wacke. Pilsen is situated on a little stream, which unites close to 

 the town with the Beraun ; and the eastern limit of the sandstone 

 seems to be a small tongue of coarse grit, which reaches the Beraun, 

 and exposes a bed of coal on its western bank. At that point, how- 

 ever, the graywacke comes in, having been brought up by a mass 

 of trap. 



Section 2. Radnitz to Rakonitz. The direction of this section 

 is nearly S. and N., Radnitz being about 12 miles east of Pilsen, 

 and Rakonitz 20 miles east of Luditz. Radnitz stands upon an in- 

 coherent coal measure sandstone ; and two bands of coal are worked 

 a little south of the town. Beyond the sandstone rises a hill of 

 graywacke shale, protruded, Mr. Ansted believes, by the agency of 

 a mass of trap visible a short way off. To the north of Radnitz is 



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