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PEOCEEDINGS OF THE GEOLOGICAL SOCIETY. [June 23, 



beds on the upper region of the western border of Val di Bove, and 

 dipping towards the latter, belonging to quite a different order of 

 things, in the history of the mountain, to those dipping away from 

 the valley, you will find it excusable that I had adopted in my 

 section of Etna (PL 9) the disposition of the stratified masses 

 according to fig. 6. To make my views clearer as to the dipping of 

 the tuff- agglomerate and lava away from the valley at the Rocca 

 Giannicola, where these rocks occur distinctly stratified, and inclined 

 at angles varying from 20° to 30° to the N. and N.W., I will add 

 a few words on an interesting phaenomenon observed by me at the 

 Rocca della Capre. A copy of my sketch, made on the spot, is added 

 here (fig. 7). You have probably observed the same fact ; and you 



Fig. 7. — Dyhes on the Rocca della Capre. Facing towards N.E. 



N.E. 



s.w. 



will see whether I agree with your opinion about it or not. Every- 

 body who examines the Rocca della Capre will agree with me that 

 it is to be considered as a remnant of the great formation of alter- 

 nating beds of crystalline trachytic rocks and tufa, which subsided in 

 consequence of the catastrophe that ultimately brought Etna to its 

 present shape. Notwithstanding the regularity which shows the 

 dip of the beds (as also the mean direction of the traversing basaltic 

 dykes, from N.E.-S.W.) to be the same prevailing in the beds of the 

 Cima (fig. 2), that is, away from the valley towards the north, there 

 is a considerable bending by zigzag inclinations of the beds in the 

 Rocca della Capre, which seems to be a consequence of the close 



