323 
tion to the inquiry whence the fragments were obtained; and to 
the assistance which this knowledge would afford in determining the 
origin of the other materials forming the Hastings sands. 
10. A letter, dated May 6th, 1840, from M. Roemer, of Hilde- 
sheim, to Dr. Fitton, on the chalk and the subjacent formations to 
the Purbeck stone inclusive in the north of Germany. 
a. Chalk with flints.—This formation, presenting characters which 
exactly agree with those of the chalk of England, is found only in 
the island of Rugen. It there consists of a white limestone, with fre- 
quent layers of flints, and includes the same fossils. 
M. Roemer is of opinion that the Rugen deposit is of the age of the 
Maestricht beds, though most geologists believe it to be younger. 
In the north of Germany there are very thick deposits of sand- 
stone and sandy marls, which correspond, M. Roemer says, to 
the upper subdivision of the chalk formation. The characteristic 
fossils are Callianassa (Pagurus) Faujasu, Belemnites mucronatus, 
small corals, &&. No Ammonites have been found init. The lo- 
calities where it occurs, are Gehrden near Hanover, Goslar, Qued- 
lenburg, and Halberstadt. 
6. Chalk without flints exists near Piena and Luneberg, with the 
same external characters as in England. Near Ilseburg, Lemforde, 
Dulmen, and other localities, it is represented by sandy marls and 
sandstones. It contains Belemnites mucronatus, many Scyphia, 
some Ammonites, &c. 
c. Chalk marl (Planer Kalk).—This formation is extensively 
distributed and well exposed in the north of Germany, and exhibits 
everywhere the same characters as in England. It contains no 
Belemnites mucronatus, but Ammonites varians, A. Mantelli, A. Gu- 
toni, Turrilites costatus, T. undulatus, Plicatula inflata, &c. 
d. Upper greensand.—This formation, as a greyish green marl, 
with grains of silicate of iron, occurs only near Dresden and near 
Wal in Westphalia; also in the neighbourhood of Hildesheim. It 
contains Ammonites falcatus, Terebratula biplicata, Ostrea carinata, 
Spatangus subglobosus, &c. 
The chalk marl im general gradually becomes more sandy, and 
passes into a sandstone with veins of oxide of iron, but which con- 
tains no fossils. The sandstone constantly accompanies the chalk 
marl. 
e. Gault.—This deposit has not been detected with certainty in 
the north of Germany, but M. Roemer thinks it may be represented 
by a marl which occurs between Hanover and Hildesheim, and con- 
tains Hamites compressus ; and by a blue clay near Ottbergen. He has 
not been able to find it near Aix-la-Chapelle. 
f. Lower greensand.—The mineralogical characters of this 
formation are the same as in England. It occurs in Saxony, at the 
foot of the Hartz, near Celfeld, near Bilefeld, and near Hattern in 
‘Westphalia, also near Aix-la-Chapelle. Its fossils are not very — 
numerous. 
g. Hils conglomerate.—To M. Roemer, geologists are indebted 
