THE CLASSIFICATION OF THE TERTIARY DEPOSITS. 129 
by shafts, which penetrate a great thickness of drift-sand, 
gravel, and clay. Immediately overlying the brown-coal, beds 
containing marine shells were found at many points by the 
German geologists ; and these fossils, when carefully studied, 
were found to differ so greatly from those of the Eocene on the 
one hand, and the Miocene on the other, that it was difficult to 
refer the beds containing them to either of LyelFs divisions. 
At the same time, the researches of Nyst and Dumont in 
Belgium, and of Sandberger in the Mayence Basin, made geolo- 
gists acquainted with other deposits containing a fauna similar to 
that found in the North German beds, and, like it, distinct from 
the faunas of both the Miocene and the Eocene. 
Somewhat later, the execution of certain new railway works 
near Paris enabled MM. Hebert and Baulin to make a careful 
study of the fauna of the Fontainebleau Sands, which had 
hitherto remained almost unknown. And in these beds were 
found assemblages of fossils agreeing very closely with those 
of the North German and Belgian localities, but differing, like 
them, from the faunas both of the Eocene and Miocene deposits. 
Lastly, the construction of a branch of the South-Western 
Bail way through the New Forest in Hampshire led to the 
exposure, in a railway- cutting near Brock enhurst, of marine 
beds containing many mollusca and corals, which were col- 
lected with untiring industry by the late Mr. F. Edwards. 
Similar fossils had previously been found at Lyndhurst and at 
some other points, both in the New Forest and in the Isle of 
Wight, but those obtained in the Brockenhurst railway- cutting 
were so numerous and well preserved as to, awaken general 
attention and interest in the subject. An examination of the 
Brockenhurst mollusca by Herr von Koenen proved conclusively 
that they agree most closely with the fossils of the North-German 
clays and sands, with those of the Fontainebleau Sands, and 
with those of the equivalent strata in Belgium and the Mayence 
Basin.. Dr.. Duncan’s examination of the Brockenhurst corals 
led him to precisely the same conclusion, which was arrived at 
by him quite independently of Yon Koenen’s researches. 
It thus came to be a recognized fact that in North Germany, 
in the Mayence Basin, in Belgium, and in the Paris and Hamp- 
shire Basins,, there exist strata which at some points are seen to 
be superimposed on Eocene strata, and at others are found 
underlying the Miocene, and that the fauna of these beds is 
very distinct both from that of the Eocene and from that of the 
Miocene. 
In the year 1854 Professor Bey rich proposed that to this 
new geological horizon, which had come to be recognized as 
existing between the Eocene and the Miocene, the name of 
Oligocene (from oXiyog, few, Kaivo c, recent) should be given, the 
NEW SERIES, VOL. IV. NO. XIII. K 
