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ancient rivers and lakes. The hordes of the Persian tyrant 
when he burnt Athens could hardly have been more numerous than 
the swarms of animals, mastodons, dinotheres, hipparions, and 
giraffes, which frequented the Miocene plains, where now stands 
Athens, and where now rise the mountains of Greece. In 
France, Switzerland, and Germany are freshwater strata, the silts- 
of ancient Miocene lakes, which all tell a similar history of the 
existence in European .areas of widespreading Miocene lands. 
There has always been a good deal of difficulty about the 
separation between the Miocene and Eocene formations. In 
the country around Paris, French geologists drew the line at 
the Fontainebleau sands, and placed the Montmartre gypsum 
and its mammalia as the summit of the Eocene series. The 
Montmartre beds belong to a freshiuater series , and the Fon- 
tainebleau (Miocene) sands are marine, and full of a characteris- 
tic shell, namely, Ostrea cyathula. Sir Charles Lyell formerly 
objected to this division, but admitted it as the only one agree- 
ing with the distribution of the Eocene and Miocene mammalia ^ 
which, after all, must be the most important test, as the mollusca 
are known to be so much longer lived as regards geological time. 
I mention these circumstances because marine shells of the 
Miocene age are said to have been found near Issoire and Le Puy 
en Yelay ; while the Eocene silts which contain Eocene mamma- 
lia both in Auvergne and at Le Puy en Yelay are undoubtedly 
freshwater. The traveller may reach Le Puy en Yelay by rail 
from Lyons by St. Etienne ; but we advise the route by Issoire 
and Brioude from Clermont Ferrand. Issoire, the ancient 
Issiodorum or Issidore, was a place of considerable importance 
in Eoman times and the residence of a praetor. The church is 
remarkable for its size, stateliness, and decoration in colours. 
It is a fine specimen of Eomanesque architecture, from its cir- 
cular eastern apse to its western front, which is, like our early 
Norman, quite plain, with billet moulding round the arches. 
Over the square front is a square tower, with two rows of round- 
headed windows, and in the centre is an octagonal tower, like- 
wise showing two rows of windows besides a short spire. Within 
the church the great height and length are very imposing, and 
the date of the building is reputed to be a.d. 939. 
I have alluded in my former paper to the geology of Issoire. 
It appears to me that there is still much to learn. The Puy 
Barnere is the highest elevation at which the tertiary fresh- 
water strata are found in all Auvergne, and Mr. Scrope makes 
the height to be 2,730 feet above the sea. This hill should bo 
visited in order to see the basalt resting at this height on dense 
masses of freshwater limestones and marls. But the most im- 
portant researches in the Issoire district are those which would 
lead to a thorough investigation and correlation of the various 
