1871.] DUNCAN — NEW CORAL. 371 



form S. Bournoni, Ed. & H. ; and S. turonensis, Ed. & H., of the 

 Faluns is the nearest fossil associate of the new form. 



The great change in the physical geography of the European seas 

 at the close of the Miocene epoch, when they no longer possessed 

 coral-reef areas, will account for the extinction of the species de- 

 scribed in this communication ; and the previous extension of those 

 areas facilitates our comprehension of the distribution of the Solen- 

 astrcece in Miocene times, and in the existing reef-faunas. 



This new crag-coral was not a member of the London-clay coral- 

 fauna ; for no reef-building forms exist in the remains of that as- 

 semblage. It belonged to the rich reef-building fauna which suc- 

 ceeded that which was associated with Nummulites, and which 

 lasted in Europe until the progressive upheaval of the Alps and 

 Western Europe, together with the subsidence of the great northern 

 barrier, determined the destruction of the assemblage of species by 

 altering the requisite external physical conditions*. 



Discussion. 



Mr. ExHEEiDGE remarked that the origin of this interesting fossil 

 seemed uncertain. It appeared, however, to be derived from some 

 other source, and not to have originally belonged to the Eed Crag. 

 In England the genus was hitherto unkno^vn in beds newer than 

 those of Brockenhurst. The presence of this single specimen showed 

 how much we had still to learn with regard to the Crag formation. 

 It was to be hoped that the coral might eventually be found attached 

 to some organism from which its age might be determined. 



Prof. T. Rtjpekt Jones remarked that he should be glad to hear 

 of more corals being discovered in the so-called CoralKne Crag. He 

 inquired whether coenepchymatous corals were necessarily reef- 

 corals, observing that this coral was referred to the Miocene on 

 account of its presumed reef-forming character. He added that 

 some of the Foraminifera of the White Crag had the aspect of ex- 

 isting western Mediterranean forms, and thus supported some of 

 Prof. Duncan's remarks. 



Mr. GwrN Jefereys observed that the distinction between the 

 fauna of the Coralline and Eed Crag was every day diminishing. 

 The appearance of the fossil seemed to betoken its derivative cha- 

 racter. Like other speakers, he complimented Mr. Alfred Bell on 

 his great intelligence in the collection and study of Crag fossils. 



Prof, Duncan, in reply, maintained that the differences between 

 deep-sea and reef-building corals were well established. Around 

 modern reefs in the deeper sea the forms were quite distinct, and 

 the deep-sea corals never presented the coenenchyma distinctive of 

 the reef-building forms. This, he suggested, might be connected 

 with the difference in the amount of sea-water with which they 

 were brought into contact, which in the surf was much greater than 

 in the almost motionless depths of the sea. 



* The species will be figured in my monograph of the Brit. Foss. Corals, Pal. 

 Soc., which is about to be completed. 



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