126 ROMER’S DESCRIPTION OF THE CHALK: 
Numerous minute straight pores traverse the stone in all direc- 
tions; they are finer than a hair, as much as three lines in length, 
and are probably the spaces out of which the spiculze of Amor- 
phozoa have been dissolved. 
The stone afforded on analysis—- 
WMGLER Wacoal bees on) aoe 
Carbonate:of lime .°. 2) % .s 0860 
Milica; waitdaie! 92! oid ert RO 
Oridesab 10m. ics Glow Dol. oa 
Wiamime) cs es) Slade) (2 Sit ae 
It is obtained from numerous quarries for building. 
At Osterfeld, a few miles from Essen, on the Ruhr, a group 
of strata perfectly similar to that above described is visible, but 
we are acquainted with it only by its fossils. 
The sandy marls which form the ridge of hills situated to the 
north-east of, and close to Coesfeld in Westphalia, are distin- 
guished from those above mentioned by a larger amount of sand, 
a light gray colour, and by a more strongly marked stratification 
and rifting (zerkliiftung) ; they likewise contain numerous spi- 
culz of Amorphozoa (?), in general well preserved ; and besides 
these, very minute blackish angular grains, which appear to be 
silicate of iron, but are so much inferior in quantity to the re- 
maining mass that they have but a very slight influence on the 
colour of the stone; on the western declivity of the hill this rock 
is exposed in numerous but small quarries, and is used for build- 
ing. 
Whether the yellower and more sandy rock of the Baumberg 
close to Coesfeld, which is said to be connected with the above 
ridge, and is characterized by numerous and beautiful remains 
of fish, is of precisely the same age with that above mentioned, 
must be left undetermined, bad weather having prevented my 
examining that hill. 
A lower chalk marl, like that of Coesfeld, occurs also at some 
points of the northern border of the Hartz mountains, for in- 
stance at Ilseburg and Stapelnburg, where it forms flat, rounded 
(gewdlbte) hills, and appears as a gray sandy marl in thin strata 
with numerous fossils. 
The lower chalk and the lower chalk marls appear to be par- 
allel formations, and are probably more closely related, palaeon- 
tologically, to the upper chalk than to the. gray chalk (pleener) ; 
but it would be vain to search for sharply defined limits, either 
