﻿part 4] PHILLIPS ASTR^A HENNAHI, AND OMONASTRMA. 



307 



to take the opportunity of expressing his appreciation of the high 

 value of the Author's researches to the stratigrapher as well as to the 

 palaeontologist. It seemed not unlikely that the species of Orion- 

 astfcea and Aulina described by the Author would provide a means 

 of more precise subdivision and correlation of the highest beds of 

 the Lower Carboniferous, and the speaker would be glad to hear 

 more about the distribution of these corals. He hoped that the 

 Author's researches would be continued, and extended to Devonian 

 corals as well as to other Carboniferous types. 



Mr. C. B. Wedd remarked upon the interest of these corals an 

 appearing at very high horizons of the Carboniferous Limestone 

 Series, and presumably at the highest coralliferous horizon in the 

 Carboniferous of this country. He compared the coral-sequence 

 suggested by these forms to that of Central Russia, where the 

 lower limestones overlying the coal-bearing sfrata show an un- 

 mistakable Dihimopliyllum fauna, while higher limestones contain 

 quite a different coral-assemblage, including several species assigned 

 to Phillipsastrcea . 



Dr. F. A. Bather asked whether the inner tube of Aulina 

 could be explained as an adaptive character due to the environment, 

 or whether it was purely an increase of calcification, inevitable with 

 the passage of time. Only in the latter aspect could it safety be 

 regarded as a certain guide to the correlation of previously un- 

 corrected beds. 



Dr. F. L. Kitchin also spoke. 



The Author, in reply to Dr. Kitchin, staled that all the species 

 of Orionastraea occurred at the same horizon — the upper part of 

 the Dibiinophyllum Zone. O. ensifer is the characteristic form of 

 the South- Western Province, whereas O. phillipsi and O. placenta 

 occur associated together in North Wales and other regions of the 

 more northern province, almost to the exclusion of 0. ensifer. 



Answering Dr. Bather, he said that the internal structure of 

 Aulina points to evolution from a simpler Phillipsastrseid type, but 

 in the general form and character of the colonies of Aulina, 

 Orionastrcea, and Oyathopliyllum regium there is evidence of 

 environmental influences affecting several stocks similarly. 



He thanked the Fellows for their kind reception of his paper, 

 and for the remarks that had been made by Prof. Garwood, Prof. 

 Sibly, and other speakers. 



