Chalk and subjacent formations in the North of Germany. 567 



small corals, &c. No Ammonites have been found in it. The lo- 

 calities where it occurs, are Gehrden near Hanover, Goslar, Qued- 

 lenburg, and Halberstadt. 



b. Chalk without flints exists near Plena 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 (Pliiner 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 in 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. 



/. 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 

 for first pointing out the existence, as distinct deposits, of the 

 Hils conglomerate and the Hils clay. 



The Hils conglomerate consists of a yellowish or brownish marl, 

 containing grains of quartz, schist, and oxide of iron. It forms 

 very thick beds, and includes in some localities very rich iron ores. 

 It occurs near Brunswick, at Goslai, and near Essen on the Ruhr 

 in Westphalia. Its fossils are very numerous, and partly identical 

 with those of the lower greensand of England; for example, it 

 contains Terebratula latissima, T. depressa, T. ohlonga, T. sella, Ostrea 

 carinata, 0. 7nacroptera, Pecten quinquecostatus.&c. M. Roemer asks 

 if it be the equivalent of the Neocomien. 



h. The Hils clay is a bluish pure clay, 100 feet thick. M. Roemer 

 considers it to be the Sjjeeton clay of England, as it contains Mya 

 depressa (Phillips), Glyphaa ornata (Astacus ornata, Phillips), and 

 Isocardia nngulata (Phillips), with a great quantity of other fossils, 

 which are in part Jurassic species, namely. Ammonites subltevis, A. 



