HOLLAND. 
221 
Oorbula gibba. 
Dosinia lincta. 
Leda lanceolata. 
-myalis. 
Lucina arcuata. 
Mactra solida. 
My a Binghami. 
Mytilus edulis. 
Nucula Oobboldiae. 
-Isevigata. 
Pecten Gerardi. 
-opercularis. 
-ventilabrum. 
Saxicava rugosa. 
Tellina prastenuis. 
Venus ovata. 
In favour of the Diestian age of the lower strata in this well 
Dr. Lorie mentions five species of mollusca as characteristically 
Lower Pliocene; all of them, however, are either living British 
forms or have been found in the Red Crag. On the other hand, 
as Dr. Lorie points out, there is the absence of many charac¬ 
teristic Diestian species, and the presence of several Arctic and 
upper Crag form^. The conclusion Dr. Lorie comes to is that 
the strata are probably of Scaldisian age, and to me the general 
character of the fauna appears like that of the Walton Crag, with 
the addition of certain northern species. Dr. Lorie brought 
forward as an argument against the Scaldisian age of the lower 
deposits, that the thickness of this division would be so much 
greater at Amsterdam than at Utrecht. Amsterdam, however, 
is on the shores of the Zuyder Zee, and in the middle of the 
great delta region which we have already shown to have formed 
a subsiding area since early Pliocene times—it is here that we 
should expect the Pliocene deposits to reach their greatest 
development. Interesting evidence is adduced by Dr. Lorie in 
favour of a great subsidence of this district, for high up in the 
undoubted Scaldisian deposits at Diemerbrug, but still 750 feet 
below the sea, a seam was found containing land and freshwater 
shells (Hydrohia similis, Zonites, sp., Succinea elegans, Clausilia 
pliocena, and Pupa muscoricm). 
One reason why especial attention is drawn to this well is 
that it seems to yield evidence of a cold area in the Pliocene 
sea; for if the lower deposits are as new as the Walton Crag, 
yet the fossils point to colder water than is evidenced in the 
British Red Crag; whilst if the sand at Amsterdam corresponds 
with the Coralline Crag, the contrast is still greater. There is, 
however, no trace of deep-water deposits either at Amsterdam 
or Utrecht. 
As a key to the correlation of the British and Continental 
Pliocene strata, the table (pp. 222, 223) has been drawn up. 
Any attempt to fix the exact limits of each division has purposely 
been avoided in it; for it must always be remembered that a 
change of physical conditions, or even a change in the fauna, 
may be far fr om occurring simultaneously in difierent countries. 
