232 Reports and Proceedings — 



EEPOETS JL.1ST1D PEOCEEDIUG-S. 



Geological Society of London. 



I— March 24, 1886.— Prof. J. W. Judd, F.R.S., President, in the 

 Chair. The following communications were read : — 



1. " On the Genus Diphyphyllum, Lonsdale." By James Thom- 

 son, Esq., F.G.S. 



The author commenced by giving a definition of the genus Diphy- 

 phyllum, and then proceeded to discuss its relations with some 

 allied forms, such as Lithostrotion, Zithodendron, and Campophyllum. 

 Diphyphyllum was shown to be restricted in Scotland to the lower 

 portion of the Carboniferous system, and not to have survived the 

 great development of volcanic action in the upper part of the Car- 

 boniferous-Limestone series, whereas in Belgium and elsewhere the 

 range of this genus was more extensive. 



It was shown that in Diphyphyllum reproduction took place both 

 by fissiparity and by calicular gemmation, examples of both forms 

 being cited. It was also pointed out that the development of central 

 vertical plates, showing a tendency to a passage into Lithostrotion, 

 was due to the corals having lived in a sea periodically affected by 

 the influx of sediment from the neighbouring shore. 



After a history of the views held by different writers since Lons- 

 dale, and especially by M'Coy, Milne Edwards and Haime, Hall, 

 Billings and De Koninck, on corals referred to this generic type, the 

 author gave a description of the species found in North Britain, ten 

 in number, of which seven were new; and after pointing out their 

 differences, showed that all exhibit a tendency to vary, and that, if 

 a sufficient series were available, a passage might be traced not only 

 between these different species, but between Diphyphyllum and the 

 various allied genera. 



2. "On additional Evidence of the Occurrence of Glacial Con- 

 ditions in the Palasozoic Era, and on the Geological Age of the Beds 

 containing Plants of Mesozoic Type in India and Australia." By Dr. 

 W. T. Blanford, F.R.S., Sec. G.S. 



After recapitulating briefly the principal facts known as to the 

 correlation of the Karoo formation of South Africa, the Gondwana 

 system of India, and the Coal-measures and associated beds of 

 Eastern Australia, and especially noticing those phenomena in the 

 different strata that had been attributed to the action of ice, the 

 author proceeded to describe the additions recently made to previous 

 knowledge by various members, past or present, of the Geological 

 Survey of India, and especially by Mr. B. Oldham and Dr. Waagen. 

 These additions had recently been published in the Records of the 

 Geological Survey of India. 



Mr. R. Oldham, in a recent visit to Australia, had come to the 

 same conclusion as all other geologists who had visited the country, 

 and clearly showed, as the Rev. W. B. Clarke and many others had 

 done, that beds containing Glossopteris, Phyllotheca, and Nceggera- 

 thiopsis were intercalated among marine beds with Carboniferous 



