408 Professor Sedgwick and Mr. Murchison on the 



culous for us to assume that we have fallen into no errors of detail. The 

 facts^ however, and the phenomena remain ; and the value of the sections, as 

 far as they are true representations of phenomena, is in a great measure 

 independent of the interpretations we ma}' have put upon them. 



The chief difference between ourselves and some other writers on the 

 structure of the Eastern Alps (especially Dr. Bouc), is in drawing the line of 

 demarcation between certain groups of strata, and determining the limits 

 between the secondary and tertiary systems. Even this difference, though 

 by itself not unimportant, does not affect the general accuracy of the accom- 

 panying sections. On this subject we have, however, written so fully in the 

 preceding chapters, that we need not repeat what we have stated ; we there- 

 lore, without further preface, commence our recapitulation. 



J. Tlie general range of the primary axis of the Eastern Alps is seen in 

 the accompanying map*; and has been descril)ed in a jirevious paperf. It 

 is now made to emerge from beneath tlse tertiary system of the Vienna basin, 

 in the Leitha-gebirge ; which thus forms a connecting link between the 

 Eastern Alps and the primary chain commencing near Presburg+. 



2. Stratified rocks, conforming to the common transition type, and with a 

 suite of characteristic transition fossils, are found, though rarely, in the Eastern 

 Alps. Beds of limestone containing organic remains are also found, though 

 still more rarely, associated with highly crystalline rocks of the central axis§. 

 These two facts show the difficulty, or, perhaps, the impossibility, of drawing 

 any exact line of separation between the primary and transition systems of 

 the Alps : and they make it probable, that the crystalline structure of some 

 of the stratified masses of the central axis, has been superinduced after the 

 deposition of the beds. They, however, introduce no confusion between the 

 primary and secondary systems of the chain ; which, in general, are clearly 

 separated from each other. We cannot even conceive such a change of mi- 

 neral structure as could lead us to confound the great zones of Alpine lime- 

 stone with the gneiss, mica-slate, &c. of the central portions of the chain. 



.3. The primary and transition systems are surmounted (in some cases un- 

 conformably) by red sandstone, rauchiDcickc, red gypseous marls, &c. which 

 sometimes, though rarely, become saliferous. These masses form one large 

 group, supposed to be on the parallel of the new red sandstone. In addition 

 to the localities enumerated in a former paper [j, they have been traced to 



* Plate XXXV. t PliiU Mag. and Annals, N. S., toI. viii. p. 85. 



+ Supra^ p. 305, § Supra., p. 306, 307. 



11 Phil. Mag. and Annals, N.S. vol. viii. p. 92, 



