2 PEOCEEDII^GS OF THE GEOLOGICAL SOCIETY. [NoV, 20, 



present level. He then points out that the general effect of these 

 views is to refer back the remains of man found at St. Acheul to an 

 indefinite date, separated from the historical period by an interval 

 during which the valley was excavated. 



In former papers Mr. Tylor stated his belief that the upper and 

 lower valley-gravels of the Somme are continuous and of the same 

 age, which he considered to be close to the historical period. In 

 this paper he states facts which appear to him to demonstrate the 

 truth of his views, and describes a number of sections near Amiens, 

 in which the levels were laid down from an exhaustive survey by 

 M. Guillom, Chief Engineer of the I^orthern Railway of Prance. 



The conclusions he has thus been able to arrive at are the follow- 

 ing : — (1) That the surface of the chalk in the Yalley of the Somme 

 had assumed its present form prior to the deposition of any of the 

 gravel or loess now to be seen there ; (2) that the whole of the 

 Amiens valley-gravel is of one formation, of similar mineral cha- 

 racter, contains nearly similar organic remains, and belongs to a date 

 not much antecedent to the historical period ; (3) that the gravel in 

 the valley of the Somme at Amiens is partly composed of debris 

 brought down by the river Somme and by the two rivers the Celle 

 and the Arve, and partly of material from the higher grounds "washed 

 in by land-floods ; (4) that the Quaternary gravels of the Somme 

 are not separated into two divisions by an escarpment of chalk pa- 

 rallel to the.river, as has been stated ; (5) that the evidence of river- 

 floods extending to a height of at least 80 feet above the present 

 level of the Somme is perfectly proved by the gradual slope and con- 

 tinuity of the gravels deposited by them ; and (6) that many of the 

 Quaternary deposits in aU countries, clearly posterior to the for- 

 mation of the vaUeys in which they lie, are of such great dimensions 

 and elevation that they indicate a pluvial period just as clearly as the 

 !N"orthern Drift indicates a glacial. This Pluvial period must have 

 immediately preceded the true Historical period. 



November 20, 1867. 



Sir George Wilham Denys, Bart., Easton Neston, ISTorthampton- 

 shire, and Septimus P. Moore, Esq., LL.B., 5 St. John's Park 

 Yillas, Haverstock Hill, N.W., were elected Eellows. 



The following communications were read : — 



1. On the Glacial and Postglacial Stettcture o/XiNCOLisrsHiRE and 

 South-East Yorkshire. By S. V. Wood, Jun., Esq., F.G.S., and 

 the Rev. J. L. Rome, F.G.S. 



[The publication of this paper is unavoidably postponed.] 



(Abstract.) 



The features of Yorkshire and North-east Lincolnshire having 



distinctive characters from those of Central and South Lincolnshire, 



the authors describe the two areas separately. In the former, their 



