Notices of Memoirs — Papers read before British Association. 445 



lias found that in the latter county the lower zones are apparently- 

 absent, and the remaining portion, representing, probably, the lower 

 part of the zone of Bel. Brunsvicensis, is characterized by the presence, 

 among the marine fossils, of plant remains, chiefly fragments of a 

 Wealden fern, Weichselia [IfantelU "}) , and by other indications of 

 fluviatile influence, suggesting the beginning of a lateral change into 

 Wealden conditions.^ 



"With the well -recognized gradual development of fresh- water 

 conditions in the Purbeck beds of the Wealden area towards the 

 close of the Jurassic period, and somewhat similar indications of the 

 reversal of this process in the top of the Weald Clay during the later 

 stages of the Lower Cretaceous, and with the above - mentioned 

 evidence for a lateral passage of part of the Lower Cretaceous 

 marine sediments of the North of England into estuarine deposits 

 further south, there seems every reason to believe that in the fresh- 

 water or estuarine strata of the English Wealden the whole of the 

 time-interval between the Portlandian and Aptien stages is repre- 

 sented, and that it would be equally erroneous to classify the series 

 entirely with the Jurassic system or entirely with the Cretaceous if 

 the hitherto recognized boundary of these systems in the equivalent 

 marine deposits of other areas is to be maintained. 



The deposits classed as Wealden in Belgium, Germany, and France 

 appear to be much more restricted in vertical range than the English 

 series, and to represent different parts of the period in different 

 places, but nowhere to imply the same long continuance of fresh- 

 water conditions in a single area. 



ZsTOTICJES OIF nynE!nVEOIE,S - 



L — British Association for the Advancement of Soience. 

 Seventieth Annual Meeting, held at Bradford, September 5-12, 

 1900. 



List of Papers read in Section C (Geology). 

 Professor W. J. Sollas, F.R.S., President. 

 President's Address. (See p. 449.) 

 Professor W. B. Scott. — Notes on the Geology and Palaeontology of 



Patagonia. (See p. 470.) 

 Professor J. Joly, F.B.S. — On the Viscous Softening of Rock-forming 

 Minerals at Temperatures below their Normal Melting Points. 



On the Geological Age of the Earth, as indicated by the 



Sodium-contents of the Sea. 



Some Experiments on Denudation by Solution in Fresh 



and Salt Water. 



On the Inner Mechanism of Marine Sedimentation. 



Vaughan Cornish. — On Tidal Eipplemarks above Low-water Mark. 

 Dr. H. Woodward, F.B.S. —Remarks on a Table of Strata, (p. 474.) 

 Professor J. Milne, F.B.S. — Report of the Committee for Seismological 

 Observations. 



^ See Survey Mem. " Borders of the Wash," o.s., slieet G9, pp. 21-25. 



