Ch.XI.] 
BRECCIAS IN SICILIAN CAVES. 
139 
of testacea. At a subsequent period, volcanic eruptions oc- 
curred, and tuff's were superimposed. The marine formation 
then emerged from the deep, and supported lakes wherein the 
fresh- water groups above described slowly accumulated, at a 
time when the mammoth abounded in the country. The 
valley of the Tiber was afterwards excavated, and the adjoin- 
ing hills assumed their present shape, and then a long interval 
may, perhaps, have elapsed before the first human settlers 
arrived. Thus we have evidence of a chain of events all re- 
garded as extremely recent by the geologist, but which, never- 
theless, may have preceded, for an immense series of ages, a 
very remote era in the history of nations. 
OSSEOUS BRECCIAS. 
Sicily. — The breccias recently found in several caves in 
Sicily belong evidently to the period under consideration. We 
have shown, in the sixth chapter, that the cavernous limestone 
of the Val di Noto is of very modern date, as it contains a 
great abundance of fossil shells of recent species. But if any 
breccias are found in the caverns of this rock they must be of 
still later origin. 
We are informed by M. Hoffmann, that the bones of the 
mammoth, and of an extinct species of hippopotamus, have 
been discovered in the stalactite of caves near Sortino, of which 
the situation is represented in the annexed diagram at 6. The 
No. 26. 
— — 
^^^^ 
c 
t' ^ 1 " vuin l' . I containing: remains of extinct quadrupeds. 
b, b, Deposits in caves, J 
C, Limestone containing remains of recent shells. 
same author also describes a breccia, containing the bones of 
