766 MK. F. W. HAEMEE ON THE [NOV. 1896, 



The difference between the three former and the latter would be 

 much more marked, if we could confine ourselves in each case to 

 the characteristic species. 



Among the many exposures of Crag, both in England and on 

 the Continent, we may have deposits representing any part of the 

 Newer Pliocene period, and it is not possible to say that a fossili- 

 ferous bed found at any one spot is the exact equivalent of one 

 met with elsewhere, nor to decide in all cases the exact order of 

 superposition of the different deposits ; but when we compare, for 

 example, such horizons as the Walton and Butley Crags, the 

 distinction is evident. And there is the same kind of difference 

 between the Scaldisien deposits of Belgium and those for which I 

 propose the name of Amstelien. Looked at broadly, the beds of the 

 Upper Crag of England arrange themselves somewhat in the 

 following order : Walton, Sutton, Butley, Norwich. It cannot be 

 said with certainty that any Belgian or Dutch zone is precisely 

 equivalent to any portion of the English Crag, but the fauna of the 

 Scaldisien and Poederlien resembles most nearly that of the Walton 

 beds, and that of the Amstelien those from Sutton or Butley. 



Each division of the Dutch strata increases regularly in thickness 

 in a northerly direction. The Diestien beds, which at Goes are 

 121 feet, at Utrecht, 65 miles to the N.E., are more than 300 feet 

 thick. The Scaldisien increases in the same distance from 69 to 

 123 feet, while the Amstelien is 262 feet thick at Utrecht, and 

 more than 450 feet at Amsterdam. At this point, the farthest to 

 the north to which we can carry it, this increment shows no sign 

 of abatement. 



The depression in which the Pliocene strata of Holland rest appears- 

 to be of the shape of a shallow basin, the sides of which rise to 

 the west, east, and south, towards Norfolk, Germany, and Belgium 

 respectively. Two sections (figs. 3 & 4, pp. 753, 761) illustrating 

 this point are given, namely, from W. to E., and from S.W. to N.E.; 

 but if a third were taken, from S.E. to N.W., that is, from Diest 

 towards Antwerp, it would also show the strata inclining towards the 

 deepest portion of the basin. 1 They are naturally thickest there, but 

 none of them give any indication of having originated in deep water, 

 the presence in the Amstelien of shells such as Mytilus edulis, Cardium 

 edule, Donax vittalus, Mactra solida, My a arenaria, Solen siliqua, JScro- 

 bicularia piperata, Purpura lapillus, and Littorina littorea pointing 

 plainly in an opposite direction. 2 The present case is not one in 

 which sediment has filled up a deep and pre-existing depression, but 

 where the bottom of a shallow sea has continued to subside, pari passu 

 with the accumulation of the material brought down into it. 3 



1 I was equally surprised and interested, when constructing these sections, to 

 find how accurately the details of the different borings fitted in with each other, 

 and with the views expressed in this paper. 



2 The considerable thickness of some of the beds of the Upper Crag in 

 Suffolk, which contain a shallow-water fauna, shows that subsidence was going 

 on there, though not so rapidly as in Holland. 



3 I have no desire to enter here on the discussion of the disputed question 

 whether the accumulation of great masses of sediment in the form of deltas 

 causes the subsidence of the sea-bottom on which they have been deposited. 



