292 THE PROCEEDINGS OF THE LINNEAN SOCIETY 



On the Bxtratropical Corals of Australia. 



By the Rev. J. E. Tenison- Woods, F.G.S., F.L.S., Cor. Mem. 

 Linn. Soc, N. S. W. ; Hon. Mem. Royal Soc, N. S. W., 

 Victoria, Tasmania, &c., &c. 



Plates IV., V., & VI. 



The Madreporaria or stony corals have two very distinct and 

 very diverse habitats. One is for the most part tropical, the corals 

 forming immense masses or reefs which form barriers, islands, 

 fringing reefs, &c., of such extent as to occupy a very large and 

 important portion of the surface of the Globe. The other is the 

 home of small, simple or compound corals which live on the floor 

 of the ocean in areas remote from coral reefs, and at all tempe- 

 ratures and depths even as much as 800 fathoms. The dredgings 

 of the " Lightning," " Porcupine," " Challenger," and that of 

 M. de Pourtales in the Gulf Stream, have made known a great 

 number of these hidden forms of life. They have also cleared 

 up many of the obscurities which a limited knowledge of species 

 necessarily gave rise to. They have largely increased the list of 

 both genera and species of corals. They have shown some of 

 the extent to which variation affects those already known, thus 

 uniting many forms hitherto regarded as distinct. Up to this 

 time however, all these discoveries have had but little effect on 

 the knowledge of Australian forms. It is true that the " Chal- 

 lenger" has visited these seas, but with what result may not be 

 known for a long time. I may say that the extratropical Madre- 

 poraria of Australia have been literally untouched. Yet a special 

 interest is attached to them on account of what has been made 

 known through geological researches. It has been ascertained 

 that our Eocene and Lower Miocene strata are particularly rich 

 in the kind of corals with which we have to deal. As a test for 

 the age and relations of the deposits no fossils could be more 

 suitable. So far as they had been studied they have led to 

 remarkable results. We have to thank Professor Duncan for 

 being the first to enter upon the field. His industry and pains- 

 taking care, together with his almost unrivalled knowledge and 

 experience in this department have been devoted to the subject, 



