1869. | DUNCAN—CORAL FAUNAS OF WESTERN EUROPE. 63 
Cidaris florigemma and the coral-reef were distinguishable. The 
lower part of the Kimmeridge group contains the relics of a reef in 
the Rochelle district ; but there are only deep-sea Mollusca and Am- 
monites to indicate the marine conditions in England, Central 
Kurope, and the rest of France. 
Coral-life had departed from our area, and did not return during 
the deposition of the Kimmeridge Clays; but a small reef-area, 
where one species of Coral alone is found, existed during the Port- 
land Oolite. But elsewhere in Western Europe* there was always 
a reef in some locality or other during the very varying conditions of 
sea-depth of the Kimmeridge age. In the middle part of the Kim- 
meridge, on the horizon of Pteroceras Oceant and Ammonites mutabilis, 
the coral-area was around Natheim and in Franconia; and in the 
upper part, the coral-sea was still absent in the west, but there were 
reefs in Franconia which were of the same general age as the Solen- 
hofen slates. There was a deep sea on our area and evidences 
of land close by; and the same evidences presented themselves 
in Western Switzerland. The variations in the depth of the 
sea-bottom must have been very considerable to have destroyed reefs 
in one area and to have enabled them to exist in another and to be 
again succeeded by deep-sea and even terrestrial deposits. The 
species of these wandering and successive reefs are identical or 
closely allied. 
The last glimmer of the Oolitic coral-life in Western Europe was in 
the Portland Oolite ; and the feeble reef of our area was part of a 
system which reached to Western Switzerland. But the progress of 
a great and general elevation of the Oolitic sea-bottoms had been gra- 
dually overcoming the temporary subsidences of portions of the area, 
and finally the land-surface of the Wealden arose over large spaces. 
Neocomian Strata. 
Until lately, the strata of this part of the Cretaceous Formation in 
England were supposed to have been almost uncoralliferous, only 
one species having been described. Mr. C. J. Meyer, however, has 
studied the Bargate stone, and has furnished me with some spe- 
cimens which give a definite character to the Neocomian sea of the 
south of England.t ‘The species are such as would, in the existing 
seas, denote a moderately deep sea and littoral tracts remote from, 
but still under the influence of, a reef-area. They are not true deep- 
sea species. Now the reefs of the Neocomian period closest to our 
area were about St. Dizier (Haute Marne) and in the Department of 
the Yonne. There were others in the Hautes Alpes; and the German 
reefs were around Schoppenstedt, Elligser, and Berklinger. The reefs 
of the Yonne were as abundant in species as those of the Oolites. 
Although the same genera were present, the species were not iden- 
tical; they were representative and grouped in the same manner. 
There must have been some great physical break between the forma- 
tion of the Neocomian reefs and the destruction of those that pre- 
* Waagen, Quart. Journ. Geol. Soc. yol. xxi. part 2, p. 14. 
+ Pal. Soc.: P.M. Duncan’s ‘ Brit. Foss. Corals,’ 1869. 
