Page:Quarterly Journal of the Geological Society of London, vol. 27.djvu/513

 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 described in this communication ; and the previous extension of those areas facilitates our comprehension of the distribution of the Solenastroeoe 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 assemblage. It belonged to the rich reef-building fauna which succeeded 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. Etheridge 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 Red Crag. In England the genus was hitherto unknown 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. Rupert Jones remarked that he should be glad to hear of more corals being discovered in the so-called Coralline Crag. He inquired whether coenenchymatous 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 existing western Mediterranean forms, and thus supported some of Prof. Duncan's remarks.

Mr. Gwyn Jeffreys observed that the distinction between the fauna of the Coralline and Red Crag was every day diminishing. The appearance of the fossil seemed to betoken its derivative character. 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.

Soc., which is about to be completed.
 * The species will be figured in my monograph of the Brit. Foss. Corals, Pal.

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