Vol. 52.] PLIOCENE DEPOSITS OF HOLLAND. 763 



true Scaldisien strata, containing species characteristic of those 

 deposits and of the Walton Crag, and especially the representative 

 form Trojphon ( Chrysodomus) contrarius, unknown from the Diestien 

 or the Coralline Crag. Below 898 feet the boring passed through 

 beds containing the usual Diestien fossils for 300 feet farther,, 

 reaching a total depth of 1198 feet, but not the base of the Diestien 

 formation. 



The borings at Amsterdam, which were carried to a depth of 

 1098 feet below Ordnance-datum, show that the dip of the Pliocene 

 and Pleistocene strata continues as far north as that city. The 

 bed containing land and freshwater shells consequently occurs at a 

 lower level than that at Utrecht, namely, at about 768 feet. 



I suggest that all the strata below the Pleistocene met with here 

 (except perhaps the last 48 feet, which do not contain fossils) 

 represent an upper zone of the English Crag, and that the Scaldisien 

 was not reached. In addition to most of the boreal species recorded 

 from this horizon at the other localities, there were found in this 

 boring Leda myalls, a characteristic shell of the latest Pliocene 

 beds, Leda minuta and Fusus scalariformis. 1 Northern shells occur 

 at all depths, though they become less abundant in the lower beds, 

 and there is a marked absence of the Coralline and Walton Crag 

 forms which are present in the Scaldisien. 



The greater part of the Newer Pliocene deposits of Holland are 

 thus, I consider, decidedly more recent than the Scaldisien of Belgium. 

 They cannot be included in that formation because they are sepa- 

 rated from it by the Poederlien, a zone which closely resembles the 

 Scaldisien, but differs widely from these deposits. I know of no 

 horizon to which this grand series of strata, more than 400 feet in 

 thickness, can be conveniently referred, and therefore propose for 

 it the name of ' Amstelien.' 2 



It does not seem probable that these Amstelien beds contain any 

 which are equivalent to the Norwich Crag. Some of the common 

 shells of that horizon occur in them, but the most representative, as 

 for example, Astarte borealis, A. compressa, A. sulcata, Tellina lata, 

 Natica catena, and N. lielicoides, are conspicuous by their absence. 

 The list of shells from the Amstelien is, however, evidently incom- 

 plete, and these species may possibly be discovered in a future boring. 

 But there is not at present any palseontological evidence by which 

 this formation can be divided into zones, except that land and 

 freshwater shells occur only in the upper part. 



If the new zone, Amstelien, which I now propose, is generally 

 accepted, it will, I think, involve the separation of the Walton bed 

 from the Red Crag, but I have for some time thought that separation 

 desirable. The difference between the faunas of these two deposits 



1 The shells from the boring at Arnhera were not preserved, with the 

 exception of a few specimens of recent species, which were found at a depth of 

 429 feet. 



2 The name ' Amstelien,' suggested to me as an appropriate one by Dr. Lorie, 

 is taken from that of the river Amstel, upon which stands the city of Amsterdam, 

 where these beds have their greatest known development. 



Q.J.G.S. No. 208. 3f 



