162 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [DeC. 13, 



zones chiefly calcareous, which were externally en\^roned by masses 

 representing certain members of the tertiary deposits*. We stated, 

 however, that when the geologist grappled with the detailed features 

 of this chain, this apparent simplicity usually vanished, chiefly owing 

 to the great movements of elevation and dislocation which it had un- 

 dergone, and which frequently caused the younger formations to dip, 

 or appear to dip, under those of more ancient date. But notwith- 

 standing these difliculties, we then separated these Alpine rocks into 

 a series of natural groups, admitting of at least a general comparison 

 with the principal geological groups of England and other countries. 

 Now, nearly all the general classification, as given in our Map, is still 

 correct, and may stand at the present day. The examples, however, 

 selected as proofs of the cretaceous and supracretaceous relations are 

 inaccurate in the north-eastern Alps ; and hence, though the legend 

 or order of colours is on the whole right, its application to parts of 

 the map must be changed, together with some essential portions of 

 our reasoning. 



Crystalline and Palceozoic Bocks of the Cent?'al Axis. — It was in 

 this great group (to which the term palaeozoic has since been applied) 

 that we noted the presence of abundance of Encrinites in the talcose 

 and chloritic limestones of the Tauern Alp. We also specially ad- 

 verted to the presence of species of British carboniferous Producti in 

 the old rocks near Bleiberg in Carinthia f . In short, we showed the 

 existence of those fossils in strata which on the one hand were con- 

 nected with masses in a crystalline state, and on the other with 

 younger fossiliferous formations. The glimpse which we then ob- 

 tained of this phsenomenon has been matured into certain induction 

 by additional recent discoveries in respect to other and older palaeozoic 

 strata J. Fossils have been recently discovered by INI. Erlach at 

 Dienten near Werfen in a portion of these transition rocks, which 

 ISl. V. Hauer has noticed. On these fossils being shown by that 

 gentleman to M. de Yerneuil and myself when we visited Vienna in 

 the summer of 1847, we identified one of the forms with the Ortho- 

 ceras gregariinn and another with Cardiola interrvpta, both well- 

 known British Upper Silurian fossils, associated with the Cardium 

 gracile (jMiinster), a shell which occurs at Feugerolles in the Silurian 

 rocks of Normandy. 



The limestones of the environs of Gratz, near the eastern extremity 

 of the chain, contain fossils of Silurian or Devonian age ; perhaps of 

 both formations. Having inspected, in company with M. de Yer- 

 neuil, a portion of this ground immediately adjacent to the city of 

 Gratz, particularly as seen in the adjacent hill of Plautsch, it appeared 

 to us that the mountain, having a chloritic sandy limestone for its 

 base, passing upwards through sandstone and grits and limestones 

 of dark grey and reddish colours, Vv^ith separating courses of chlo- 



* Trans. Geol. Soc. Lond. vol. iii. New Series, p. 301, and Phil. Mag. and Annals 

 of Phil, vol viii. Aug. 1830. 



t See Phil. Mag. and Annals of Phil. vol. viii. Aug. 1830. 



+ The exact position of which is indicated in the new geological map of M. A. 

 Morlot, entitled ' Geologische Ucbersichtbkarte der Oesterreichischen Alpen.' 



