1869.] DUNCAN—CORAL FAUNAS OF WESTERN EUROPE. 53 
There has been much progress made in connecting the phenomena 
of existing reefs with those of the past, with the idea of establishing 
propositions upon which geologists could reason. Many years since, 
Lieut. Nelson* proved that sediments which were supposed to be 
characteristic of Oolitic and Cretaceous rocks were imitated around 
the Bermudas; and of late years much has been written upon coral 
limestones and marls, and the metamorphosis of coral rocks into 
dolomites has been hinted at. 
Speculations have also been published respecting the influence 
of the subsidence of reefs, their becoming covered up with deep-sea 
deposit, and the creeping of deep seas over littoral tracts and land 
upon the notions of contemporaneity f. 
In 1863§ the similarity in general arrangement of the Mio- 
cene reefs of the West Indies to those now encircling many of the 
islands was announced ; and it was stated that the species of the old 
reefs could be divided into those which lived amongst the boiling 
surf, in the quiet lagoon, along a barrier reef, and in deep water 
close by. The raised reefs of San Domingo were shown to link 
the specialities of existing reefs to those of the past; and an ex- 
amination of still older coral formations on the same area indicated 
that even in the Lower Cretaceous rocks there were proofs that the 
same external conditions and the same grouping of coral forms were 
as characteristic of the ancient as of the Caribbean reefs. 
Again, the study of the Sicilian and Crag deposits proved that the 
former seas, out of the range of reefs, had coral species representa- 
tive of those now living in deep and abyssal water, and occasionally 
just below low spring-tide mark. 
Moreover many English geologists || had shown that coral reefs 
formed parts of Palsozoic and Oolitic landscapes; and Stoppani 4 
proved that the Azzarolan banks were formed by a branching Ma- 
dreporarian. 
With these facts and theories at hand there is a demand for their 
utilization in some common inquiry; and this communication is an 
attempt to explain some of the former physical conditions of Western 
Europe by comparing the fossil coral faunas with the existing**. 
It commences with a notice and a description of the typical species 
of the coral fauna of the deep and abyssal seas which bound con- 
tinents remote from reef areas; and then follow remarks upon 
* Trans. Geol. Soc. 2nd ser. vol. v. 
t S. P. Woodward held this opinion. (Geol. Mag. vol. i. “Review of the 
Dolomite Mountains.’’) 
{ Duncan, Report on Brit. Foss. Corals, Brit. Assoc. 1868, 1869. 
§ Quart. Journ. Geol. Soc. vol. xix. p. 406. 
|| Ramsay and Murchison; Wright, Cotteswold Club, 1868. 
¥ Pal. Lombard. 
** Some theoretical considerations bearing upon this communication will be 
noticed in :—Description Foss. Corals of the West India Tslands, 1863. Report on 
British Fossil Corals, read at Norwich, 1868, and Exeter, 1869. Palzontograph. 
Soc. Supp. Brit. Foss. Corals, 1865. Tertiary (written 1864). Since this essay was 
read the specimens of corals dredged up in the ‘Porcupine’ expediticn have 
heen examined by me, and Count Pourtales has sent me most of the types of the 
deep-sea coral fauna off Florida and the Hayannah. [I still find that the deep-sea 
coral faunas differ essentially from those of coral-reef areas. 
