1 



i 



.e 



t- 

 le 



11- 



it 

 lie 



: d ' 



ies 

 10- 



are 



are 



LOll 



j 



th'a 



e to 



reat 



vol- 

 ons, 



(T Of 



nces 

 larly 



j» 



>u 







C.t. XXIIL] 



OF VOLCANIC REGIONS. 



597 



Besides tlie continuous spaces of subterranean disturbance, 

 f which we have merely sketched the outline, there are other 

 liscoimected volcanic groups of which several will be men- 

 tioned hereafter 



yf active and extinct volcanos not to be confounded 



We 



extinct and active volcanos, even where they appear to run in 

 the same direction ; 



for ancient and modern systems may m- 

 terfere with each other. Already, indeed, we have proof that 

 this is the case ; so that it is not by geographical position, 

 but by reference to the species of organic beings alone, 

 whether aquatic or terrestrial, whose remains occur in beds 

 interstratified with lavas, that we can clearly distinguish the 

 relative age of volcanos of which no eruptions are recorded. 

 Had Southern Italy been known to civilised nations for as 

 short a period as America, we should have had no record of 

 eruptions in Ischia ; yet we might have assured ourselves 

 that the lavas of that isle had flowed since the Mediterranean 

 was inhabited by the species of testacea now living in the 



Neapolitan seas. 



With 



assurance, it would not have 



been rash to include the numerous vents of that island in the 

 modern volcanic group of Campania. 



On similar 



may infer, without much 



era 



some 



submarine 



di Noto in Sicily. But, on the other hand, the lavas of the 



Euganean Hills and the Yi 

 the range of earthquakes 



Northern Italy, must 

 volcanic system ; for wl 



flowed, the seas were inhabited by animals of the Eocene 

 period, almost all of them distinct from those now known to 

 live, whether in the Mediterranean or other parts of the 



globe . 



if'- 



