On the Fossil Corals of the Australian Tertiary Deposits. 1 39 



February 9th, 1870.— Prof. Huxley, LL.D., F.R.S., President, 

 in the Chair. 



The following communications were read : — 

 1. " On the Fossil Corals (Madreporaria) of the Australian 

 Tertiary Deposits." By P. Martin Duncan, M.B. Lond., F.B.S., Sec. 

 Geol. Soc, Professor of Geology in King's College, London. 



The author noticed the history of our knowledge of the South- 

 Australian Tertiary Deposits, and indicated the general distribution 

 of the fossiliferous beds from which the corals forming the subject 

 of his communication were derived. These were said to be con- 

 fined to the region west of Cape Howe, prevailing especially in the 

 province of Victoria, where they had been admirably surveyed by 

 Mr. Selwyn and the officers under him, and to consist chiefly of 

 limestones covered, and in some cases underlain, by great outflows of 

 basalt. The author then gave a list and descriptions of the species 

 (31 in number) of fossil Madreporaria obtained from these South- 

 Australian Tertiary beds, followed by remarks on the characters and 

 relations of the more remarkable forms, and on the localities where 

 they have occurred. From his examination of these fossils, he 

 objected to the application of the divisions adopted in European geo- 

 logy to the deposits in which they are found. He then compared the 

 assemblage of corals obtained from the South- Australian Tertiaries 

 with those found in various deposits elsewhere, or living in the 

 existing seas. The species were stated not to belong to reef-building 

 forms, but to such as now occupy the sea-bottom from low spring- 

 tide mark to the depth where Polyzoa abound. Of these, 20 genera 

 were said to be now represented in the Australian seas ; but only 

 three of them to have species in the Tertiaries, viz. the cosmopolite 

 Trochocyathus, Flabellum, and Amphihelia. The fossil species of 

 these were stated to be quite distinct from those now living in the 

 neighbouring sea. Two species, viz. Flabellum Condeanum and F. 

 distinctum, are living in the Chinese, Japanese, and Red Seas ; the 

 author's Plecotrochus elongatus is very nearly allied to the Chinese 

 F. Condeanus ; and a Deltocyathus is regarded by the author as only 

 a varietal form of a living West-Indian and European Miocene 

 species (D. italicus). Three species are common to the Australian 

 and European cainozoic deposits. Several of the species were said to 

 present curious anomalies of structure, such as so frequently appear 

 in Australian forms, and those of the different beds to exhibit so close 

 a general resemblance, that they offer no evidence of great changes 

 having taken place during the deposition of the whole series of sedi- 

 ments. The evidence afforded by the fossil corals ]ed the author to 

 conclude : — that, at the time of the formation of these deposits, the 

 central area of Australia was occupied by sea, having open water to 

 the north with reefs in the region of Java, and with openings into 

 the Mediterranean and Sahara to the north-west ; that Continental 

 India did not form part of a great continent ; that the greater part 

 of America was submerged, and the Caribbean sea a coral-area ; that 

 the bulk of the land was situated in the north and south ; and that 



