62 
THE GEOLOGIST. 
top to bottom, which clearly could not be done without that formation 
being capped somewhere by a mass of the next overlying one, to show tho 
real top ; its bottom being shown by the outcrop of, or by wells being sunk 
through to, the formation next below. 
6. Crag (of Prestwich). — Near the edge of the Chalk escarpment near 
Folkestone, and to a smaller extent in other like places, there is found a 
deposit of sand, often ferruginous, the age of which is not yet made out 
with certainty. It seems not to be connected with any of the older 
Tertiary beds, and it is not like any of the Drift-beds of the district. From 
the occurrence of a peculiar set of fossils in a pipe of this sand in the Chalk 
above Lenham, Mr. Prestwich was led to class it with the " Crag," an 
Upper Tertiary formation of much later date than any we have been con- 
sidering. The fossils, however, being only in the state of casts in iron- 
stone, and merely from a small pipe, the evidence is hardly conclusive, and 
the classification must be looked on as provisional. There is therefore a 
very doubtful point in the Tertiary Geology of their county for the " East 
Kent Naturalists " to work out. 
Geological Society. — December 2, 1863. — 1. "On the Correlation of 
the Oligocene Deposits of Belgium, Northern Germany, and the South 
of England." By Herr Adolf von Koenen. Communicated by F. E. 
Edwards, Esq., F.G.S. Railway-cuttings in the New Forest (Brocken- 
hurst, etc.) have recently exposed certain marine beds overlying the Lower 
Headon (freshwater) series, and containing fossils hitherto unknown in 
England, but which, as Herr von Koenen showed, constitute the marine 
equivalent of the Middle Headon strata. 
The author gave an exposition of the current opinions upon the correla- 
tion of those English and foreign " Upper Eocene " or " Lower Miocene " 
strata, to which Professor Beyrich has given the name " Oligocene," and 
briefly sketched their distribution and limits upon the Continent. He then 
gave a list of fifty-nine New-Forest (Middle Headon) fossils, which he had 
determined, and stated that, of this number, forty-six occur in the Lower 
Oligocene of Germany, and twenty-thi'ee are characteristic of that forma- 
tion ; twenty-one of these species occur in the Barton Clay, four in tbe 
Middle Oligocene, and eight are peculiar to the Brockenhurst beds. He 
therefore concluded that the Headon and Brockenhurst strata are on the 
same horizon as the Lower Oligocene ; and he confirmed the opinion of pre- 
vious observers, that the Hempstead beds are the equivalent of the " Gres 
de Fontainebleau " and of the Middle Oligocene of Germany. 
2. " On the Liassic Strata of the Neighbourhood of Belfast." By Ralph 
Tate, Esq., F.G.S. 
In the neighbourhood of Belfast the following members of the Lias for- 
mation were stated to occur, namel}'' : — The zone of Ammoniies Backlandiy 
the White Lias, and the zone of Avicula contorta. 
The characters of these subdivisions in the district under consideration 
were described in detail by Mr. Tate, who gave sections of the beds ex- 
posed in Colin Glen and at Cave Hill, at which localities the three zones 
are seen ; he also gave sections of the Avicida contorta beds as exposed at 
Woodbarn and at Whitehead, and lists of the fossils found in the strata of 
each subdivision at the localities mentioned, noticing that, in the zone of 
Ammonites BucJdancli, that Ammonite is replaced by A. intermedius, the 
other fossils being of the same species as occur in that zone in England ; 
and he concluded with some general remarks on the distribution of the 
members of the Lias in the North of Ireland. 
3. "Notes on the Devonian Bocks of the Bosphorus." By W. R. 
