390 Professor Sedgwick, and Mr. Murchison on the 



4. Coralline, white limestone, calcareous and arenaceous marl, kc. 



The finest exhibition of this rock is seen in the tabular elevation of Wildon, 

 situated on the right bank of the Mur, near its junction with the Kainach. 

 This hill, celebrated as one of the astronomical stations of Tycho-Brahe, 

 rises to the height of 600 or 700 feet above the neighbouring plains; and 

 the upper part of it^ in thickness more than 400 feet, consists of a horizon- 

 tal, strong-bedded, yellowish white limestone, here and there charged with 

 many coralline bodies, alternating with some thin wayboards of marl, and 

 with marl containing many irregular calcareous concretions. It is a splendid 

 example of a coralline limestone of a tertiary age, exhibited on a grander 

 scale than the English geologist has been accustomed to see in the secondary 

 coral rag of his own country. 



Many of the masses have a mottled appearance, resulting from a number of 

 spheroidal and cylindrical concretions, formed of concentric layers of white 

 carbonate of lime, probably produced in the first instance by organic bodies, 

 the traces of which are now lost. In the harder and tiiicker beds there are 

 many cavities, originally containing various corallines, of which we now only 

 find the impressions standing out in relief from the interior of the cells*. 

 In the lower part of Wildon the limestone becomes more marly and concre- 

 tionary, and passes into sandy argillaceous marls, which form the prolongation 

 of beds composing the wine-hills of Sausal. 



A line drawn from Wildon about S. by E., at right angles to the prevailing 

 dip of the formations, falls upon the hill of Ehrenhausen, where the castle 

 stands upon a similar coralline and concretionary white limestone f. 



The shells we found at Wildon and Ehrenhausen are a Mytilus, a Cardium, 

 two species of Pecten, of which the smaller is the Pecten infiwiatus of Des- 

 hayes ; one species of Cerithium, Conus Aldrovandl? of Brocchi ; Balanus 

 crassus ? of the English crag; small Nummulites, probably of the species 

 N.complanatus; many corals of the genera Astrea and Flustra; tubes resem- 

 bling the cells left by a Teredo or Pholas ; club-shaped bodies (Pistulanae 

 of Lamarck) traversing corals, and the claws of a species of Crab. 



* A. similar concretionary and coralline structure is seen in the mottled tertiary marble of Costa 

 Lun<-a, described by one of the authors in a former memoir " On the Tertiary Formations near 

 Bassano," Annals of Philosophy, vol. v. p. 401 : and the coralline limestone of Monte Viale 

 in the Vicentine, described by M. Brongniart, may also be cited as an analogous rock. These 

 examples of similar structure do not prove the several rocks to be of the same age. The leitha- 

 kalk of the Vienna basin is however not only in structure very like the limestone of Wildon, but 

 is, we believe, exactly on the sawe parallel. > 



■\ Plate XXXVI. fig. 16. 



