VOGL — GEISTERGANG OF JOACHIMSTHAL. 3/ 



shock increased in energy with the depth, and reached its maximum 

 at an horizon of 100 fathoms* underground. 



Previous to the earthquake in question, another had been felt at 

 Schemnitz on April 6th, 1854, at 6 o'clock p.m. It followed the 

 same line of direction, and was perceived over a larger extent, but it 

 was of less intensity. Its maximum point was also situated im- 

 mediately beneath the area on which Schemnitz is built ; and intense 

 shocks were felt at Windschacht ; but they were not at all perceived 

 in the interior of the mines. [Count Marschall.] 



On the Tertiary Chelonia o/" Austria. By Dr. Peters. 



[Proceedings of the Imperial Academy of Sciences at Vienna, Jan. 4, 1855.] 



In his Memoir on the remains of Chelonians in the Tertiary deposits 

 of the kingdom of Austria, M. Peters observes that these fossils, 

 all belonging to the freshwater genera Trionyx^ Emys, and Chelydra, 

 may be of great use in throwing light on the mutual relations of the 

 Tertiary freshwater deposits with the seas of that period. Most of 

 these fossils were found in Lower Austria and in the S.W. parts of 

 Styria. One specimen is from the strata of Hammersdorf, near 

 Hermannstadt in Transylvania. Two new species of Trionyx {Tr. 

 Vindobonensis and Tr. Stiriacus\ Tr. Partschi^ Fitz., Emys Lore- 

 tana, Meyer, and a Chelydra, closely allied to Ch. Decheni, Meyer, 

 are described in M. Peters' s Memoir. 



[Count Marschall.] 



On a Recently Discovered Metalliferous Deposit in Northern 

 Bohemia. By M. Vogl. 



[M. Haidinger's Report to the Imperial Geological Institute of Vienna, 



Nov. 7, 1854 f.] 



The Geistergang (Ghost' s-vein) is a rich metalliferous deposit dis- 

 covered at Joachimsthal, in Northern Bohemia, in October 1853. 

 M. Vogl describes it as being formed of decomposed porphyry 

 containing frequent cavities occupied by a talcose substance mixed 

 with capilliform native silver and with black pulverulent oxyd 

 of silver (Silberschwarze). Its metalliferous portion is a compact 

 compound of several species of pyrites, blendes, and metallic sul- 

 phurets, especially of cobalt and nickel, among which the silver is 

 found, either native, in shape dentiform or filiform, or in the state 

 of both black and red antimoniferous sulphuret (Rothgiltigerz.) 



The vein rests on slate, and is covered by porphyry ; it becomes 

 richer as it is closer in contact with porphyry, and attains its maxi- 

 mum richness where it divides into two branches and goes through 

 the porphyry. Farther on, its metalliferous ores diminish gradually 

 as the slate appears more and more in the roof of the vein. 



The thickness of one of these branches varies from 3 to 4 inches ; 

 that of the other from 3 to 8 inches. 



* About 622 English feet.— Tkansl. 



t Jahrb. K. K. Geol. Reichsans. 1854, pp. 611, &c. 



