30 
\ 
difference of latitude and the diversity of conditions of deposi¬ 
tion. The relations of the fossils of the several horizons were 
dwelt upon, and the evidence whicli they afforded v\hth respect 
to the climate of the period, showing a progressive refrigeration 
from the lower to the upper strata, in the latter of which the 
siib-Arctic character of some of the shells indicated that the 
glacial epoch was already making its approach felt in the 
Mediterranean region. He then sketched the physical geography 
of Italy during the deposition of these strata, and described its 
terrestrial fauna, most of the species of which, he said, had 
inhabited England during the same period, as proved by their 
remains found both in the coralline and red crags. After 
describing the fossils of the Belgian and English crags, the 
evidence of which relative to the climate of the period corrobo¬ 
rated the conclusions arrived at by the study of the sub-Apennine 
beds, he inquired what evidence we had for estimating the 
length of the interval which had elapsed since these strata had 
been deposited. Etna, the immense bulk of which is post¬ 
pliocene, proves that that interval must have been enormous; 
but the changes in the physical geography of England, known 
to have taken place in the same interval, are even more calcu¬ 
lated to strike the imagination. Since the latest of the crags 
was deposited we have proofs that England has been twice 
united to the Continent, and once in great part submerged 
several hundred feet beneath the sea. Sir C. Eyell, basing his 
calculations upon the rate at which oscillations of level of the 
earth’s crust are known to be taking place at the present day, 
estimated that such a rising and sinking required at least 
22’4,000 years for its completion. Dr. Croll, of the Geological 
Survey of Scotland, proceeding upon astronomical data, has 
computed that the glacial period had its commencement more 
that 240,000 years ago, and we have clear evidence that this 
also happened long after the termination of the crag or pliocene 
period. 
April 1st. —The Bev. Canon Baine read the following 
paper;— 
Within the last few weeks the excavations for the Exhibition 
