1862.] 39 



This structure is then shown to apply to the Waveney, where 

 there is a terrace of gravel on both sides of the valley at a level of 

 about 40 feet above the river, and to which position, but to a more 

 lacustrine condition, the Hoxne deposit belongs. Sections are given 

 of this valley, and also of the valleys of the Lark at Icldingham and 

 of the Ouse at Bedford, showing the constancy of this structure. 

 In the valley of the Thames the phenomena are more complicated 

 and are reserved for future consideration, notice being merely taken 

 of the implements found at Herne Bay and Whitstable. 



Owing to the absence of marine newer and post-pliocene beds in 

 the North of France, these gravels are better exhibited and more 

 distinct, being free from rock-fragments and boulders foreign to 

 their own origin and area. Hence it has arisen that this part of the 

 geological series has been more investigated in France than in 

 England. In the admirable review of the Quaternary formations by 

 M. d'Archiac, two general conclusions are set forth. With the first 

 of these the author perfectly agrees. It is that each large hydro- 

 graphical basin, although the boundaries may not be marked by any 

 important elevation, has its own exclusive drift, and that in no case 

 is there a mixture of the transported materials of the separate basins. 

 The author, however, dissents from the opinion that these drifts, 

 containing the remains of large extinct mammalia, have in any way 

 depended on or resulted from any general cataclysm destroying these 

 creatures nearly simultaneously over wide continents and entombing 

 their remains in the sand, gravel, and shingle of the valleys and 

 in the earth of the caverns ; neither can he consider the excava- 

 tion of the valleys to be anterior to the spread of the drift-gravels. 

 On the contrary, he refers the phenomena to long-continued river- 

 action. 



An account is then given of the valley of the Somme, and it is stated 

 that the relation between the high- and low-level gravels, which 

 could not be proved with respect to St. Acheul and St. Roch, has 

 been made clearly apparent at Montiers near Amiens, by the opening 

 of a new ballast-pit on the side of the railway, some 50 feet above 

 the level of the old gravel-pits in the valley just below, and in which 

 latter Jlint -implements were first found by the author in the spring 

 of last year. In the upper ballast-pit a considerable number of land 

 and freshwater shells and some mammalian bones have been found, 



