32G 
TlIK (!K,0I,I)(I1S'I', 
estuarine formations, and evidence is not wanting to support the 
inference that a large portion of the mountain is even of posterior 
date. 
The marine tertiary strata of Cefali and Nizzeti are considered by 
Sir C. Lyell as slightly younger than the Norwich Crag, and " if so, 
the great mass of Etna, or all that is of sub-aerial origin, being newer 
than the Nizzetti clays, must be, geologically speaking, of extremely 
modern date. Its foundations were probably laid in the sea, and 
were in all likelihood contemporaneous with the basalts and other 
igneous products of the Cyclopean Isles and Aci Castello, which 
belong to the period of the fossil shells of Nezzeti and Cefali. When 
that fauna flourished, the area where Etna now rises was probably a 
bay of the sea, afterwards converted into land by the outpourmg of 
lava and scoriae, as well as by the slow and simultaneous upheaval of 
the whole territory. During that gradual rise the ancient river- plain 
of the Simeto, in which were embedded the remains of elephants and 
other quadrupeds, together with certain marine strata (those of 
CamuUu) formed near the mouth of that river, acquired their present 
comparatively elevated position. The local eruptions of La Motta 
and Paterno took place about the same time — i. e., during, or im- 
mediately after the deposition of the older alluvium, when also the 
leaf-bearing tuffs of Fasano were formed. In the course of the same 
long period of elevation the cone of Trifoglietto, and probably the 
lower part of the cone of Mongibello, were built up. Still later, the 
cone last mentioned, becoming the sole centre of activity, over- 
whelmed the eastern cone and finally underwent in itself various 
transformations, including the truncation of its summit and the 
formation of the Val del Bove on its eastern flank. At length the 
phase of lateral eruptions, which is still in full vigour, closed this 
long succession of events — changes which may have required 
thousands of centuries for their devellopment, although in the same 
lapse of time the molluscous fauna of the MediteiTanean has scarcely 
undergone a twentieth part of one entire revolution." 
After a recapitulation of the principal arguments of the third part, 
the author concludes his admirably lucid and logical paper with the 
expressal of his conviction, that " upheaval has no where played such 
a dominant part in the cone- and crater-making process as to warrant 
the use of the term ' elevation-craters' instead of cones and craters of 
eruption — a conviction in which we think most reflecting geologists 
will concvu", and which seems, through the medium of Sir Charles's 
paper, to have attained influence in the head-quarters of the 
supporters of the " elevation-theory" from the fact, that the 
(leological Society of Berlin, at which city that hypothesis was first 
propounded, has, by permission requested of its author, translated it 
into German. 
No doubt the weight of such names as those of the late venerable 
Baron Humboldt and M. Elie de Beaumont caused the " elevation 
doctrine" to be received generally more from the credibility of such 
authorities, than from ihe merits of the doctrine itself In the 
