1870. ] DUNCAN—AUSTRALIAN CORALS. 313 
IX. Concrvston. 
When the list of the fossil corals of the Australian tertiaries is 
compared with that of the forms living in the Australian and New- 
Zealand seas, it becomes evident that none of the recent species arc 
represented in the Cainozoic strata. Of the twenty genera now 
existing around Australia, out of the immediate vicinity of coral- 
reefs, only three had species in the Tertiaries. Trochocyathus, Fla- 
bellum, and Amphihelia, very world-wide genera, were represented 
in the tertiary strata by species which were very distinct from those 
now inhabiting the South-Australian and New-Zealand seas. The 
species which have been found as fossils, and which still exist in the 
Chinese, Japanese, and Red Seas, are Flabellum Candeanum, and F. 
distinctum. The Chinese Placotrochus Candeanus is very closely 
allied to P. elongatus from the Hamilton tertiaries and Cape Otway, 
and the Deltocyathus is equally so to a West-Indian recent species. 
The alliance of the coral faunas of the Australian Tertiaries and of 
the surrounding coral seas is thus very slight; and the recent species 
have not been found in the uppermost of the Tertiaries. There are 
three species common to the Australian and the European Cainozoic 
deposits ; so that the alliance of the Australian fossil fauna is as great 
with the European Cainozoic fauna as it is with that of the corals of 
the tropical seas to the north-east. There is a well-marked species 
of the Lower Miocene or Oligocene of Mayence, still living in Port 
Jackson, but it has not been found in the tertiary deposits close by. 
The fossil fauna now under consideration cannot be satisfactorily 
compared with any others with the view of determining a geological 
relationship. The bulk of the species are peculiar, and such genera 
as Conosmilia and Palwoseris are very characteristic. Their species, 
as well as the Australian Caryophyllic, Trochocyathi, and Spheno- 
trochi, present those anomalies which appear to distinguish the forms 
of the New-Holland fauna. The presence of the Italian species 
Conotrochus typus, and of the Tortonese Balanophyllia cylindrica and 
Deltocyathus rtalicus, in the Australian Tertiaries is quite in keeping 
with the well-known dispersion of the Maltese and Bund corals 
and Kchinodermata. 
The corals of the Australian Tertiaries are very characteristic. They 
were not reef-builders, but forms which tenanted the sea-bottom, 
from low spring-tide mark to the depth where Polyzoa abound. The 
species of the different beds have so great a general and exact re- 
semblance, that they do not offer evidence of any great biological 
changes having occurred during the deposition of the whole of the 
fossiliferous tertiary sediments. It is therefore not consonant with 
the rules of classificatory geology to subdivide the sediments into 
such series as Oligocene, Lower, Middle, and Upper Miocene, and 
Pliocene, which for the most part have very distinct faunas in the 
European area. The diagnosis of the age of the tertiary deposits 
by the percentage system cannot as yet be applied to the Australian 
sedimentary beds, in consequence of the Mollusca not having been 
sufficiently studied ; and the comparison between the existing Austra- 
VOL. XXVI.—PART I. Z 
