CONTENTS. XXl 



PAGE 



Submarine lavas of the bay of Trezza not currents from Etna Internal 

 structure of the cone of Etna Val <li Calanna Val del Bove not an ancient 

 crater Its precipices intersected by countless dikes Scenery of the Val del 

 Bove Form, composition, and origin of the dikes Lavas and breccias 

 intersected by them ..... 75 



CHAPTER VIII. 



Speculations on the origin of the Val del Bove on Etna Subsidences 

 Antiquity of the cone of Etna Mode of computing the age of volcanos 

 Their growth analogous to that of exogenous trees Period required for the 

 production of the lateral cones of Etna Whether signs of Diluvial Waves 

 are observable on Etna . . . . . .95 



CHAPTER IX. 



Origin of the newer Pliocene strata of Sicily Growth of submarine for- 

 mations gradual Rise of the same above the level of the sea probably caused 

 by subterranean lava Igneous newer Pliocene rocks formed at great depths, 

 exceed in volume the lavas of Etna Probable structure of these recent sub- 

 terranean rocks Changes which they may have superinduced upon strata 

 in contact Alterations of the surface during and since the emergence of the 

 newer Pliocene strata Forms of the Sicilian valleys Sea cliffs Proofs of 

 successive elevation Why the valleys in the newer Pliocene districts cor- 

 respond in form to those in regions of higher antiquity Migrations of 

 animals and plants since the emergence of the newer Pliocene strata Some 

 species older than the stations they inhabit Recapitulation . 103 



CHAPTER X, 



Tertiary formations of Campania Comparison of the recorded changes in 

 this region with those commemorated by geological monuments Differences 

 in the composition of Somma and Vesuvius Dikes of Somma, their origin 

 Cause of the parallelism of their opposite sides Why coarser grained in 

 the centre Minor cones of the Phlegrsean Fields Age of the volcanic and 

 associated rocks of Campania Organic remains External configuration of 

 the country, how produced No signs of diluvial waves Marine Newer 

 Pliocene strata visible only in countries of earthquakes Illustrations from 

 Chili Peru Parallel roads of Coquimbo West-Indian archipelago 

 Honduras East-Indian archipelago Red Sea . . . 118 



CHAPTER XL 



Newer Pliocene fresh-water formations Valley of the Elsa Travertins of 

 Rome Osseous breccias Sicily Caves near PalermoExtinct animals 



