1809. ] DUNCAN—CORAL FAUNAS OF WESTERN EUROPE. 69 
Godwin-Austen and Sharp concerning the relations of the English 
Upper Green Sand and Lower White Chalk,—that, in fact, the first 
deposits were covered by the last during a period of subsidence, and 
that oceanic conditions prevailed over the littoral. Since the corals 
of the Gosau district have been compared with those of Les Bains de 
Rennes, the Montagne des Cornes, Martigny, and Figuicres, it has 
become evident that large tracts of the French, Spanish, and Austrian 
areas were occupied by coral reefs, which were formed and destroyed, 
after producing enormous sediments, whilst the oceanic conditions of 
the British, Belgian, and North German areas prevailed. There were 
also deep-sea formations going on far away to the east whilst the 
reefs of Gosau were flourishing. Yet the oceanic conditions out- 
lasted those of the reefs, and the sediments of the deep sea evidently 
covered up those of the reef-areas as the great subsidence of the 
period progressed. There were then two coral faunas living at once 
on the Western European area. The reef-species were very nume- 
rous, and were closely allied not only to the Neocomian forms, but 
also to those of the Oolites. The alliance is greater with the Neo- 
comian fauna than with the Oolitic; but there is a remarkable simi- 
~ larity of “ facies” between the three groups of forms, which reminds 
the naturalist of the peculiarities of the existing corals of the Pacific. 
This arises from there being many genera which were represented 
in the Lower Cretaceous reefs, and which exist in those of the 
Pacific. 
The fauna of the Upper and Lower White Chalk, on the other 
hand, is essentially represented by that of the existing deep-sea 
coral fauna of the North Sea and the Atlantic, on the west coast of 
Treland, down to the Straits of Gibraltar. The Caryophyllie of the 
Chalk are closely allied to the existing species, and the branching 
Synhelia is represented by Lophohelia. The homotaxis of the Cre- 
taceous deposits and those now forming is very extraordinary. 
The uppermost deposits of the White Chalk in Denmark and 
Holland contain a few traces of shallow-water and reef corals; and 
the end of the Cretaceous coral-period resembled that of the Oolitic. 
Nummulitic Period. 
The fossil corals of the London Clay, Bracklesham, and Barton 
beds, indicate varying bathymetrical conditions : some of the species 
were littoral, and others were wanderers from a reef-area. The 
corresponding deposits on the other side of the Channel contain 
many of the British species, and were formed under the same ex- 
ternal conditions. The reefs of the period covered vast areas. The 
typical reefs were in Styria, about Oberburg; others were in the 
Vicentin, the Tyrol, Switzerland, the Maritime Alps, Corbiéres, Nice, 
the Pyrenees, and Biarritz. The reefs were continued into the Cri- 
mea, Egypt, Syria, and Arabia; and the Hala Mountains, in Sindh, 
contain as great an aggregation of reef-making genera as modern 
reefs. The Oberburg fauna was highly developed, and contained all 
the varied styles of mzandriform, branching, and massive corals 
VOL. XXVI,—PART I. F 
