Chap. XIV.] LOWER SILURIAN IN SWEDEN AND NORWAY. 
347 
any intervening crystalline schists. In such cases the lowest sandstone, which is 
used as a millstone, is simply a re -aggregated , granite, the arkose of Brongniart ; 
the materials haying been derived from the subjacent rock. 
Oldest Silurian Strata or Sweden resting on Granite. 
(From ' Russia-in-Europe,' p. 16.) 
b. Alum-schist. a. Fucoid-sandstone. a'. Arkose. gr. Granite. 
Now, whether the subjacent rocks be composed of granite, granitic gneiss, or 
flinty slates, and quartzose or other crystalline masses, the fundamental strata 
in which any traces of former life can be detected are sandstones and schists, 
which stand in the place of the lower fossiliferous beds of Britain, and of that 
1 Primordial Zone ' in Bohemia which will presently be noticed. The bottom 
beds contain Fucoids, or casts of Sea-weeds only ; but the lowest band of schist 
is well characterized by its fossils in several parts of Sweden, and particularly 
at Andrarum, where it contains Trilobites of the genera Paradoxides, Olenus, 
Conocephalus, Agnostus, &c. 
The limestones which next overlie (c, of the section at p. 346), and which 
abound in Orthidse, large Orthocerata, Trilobites, and Cystideae, are distinctly 
the equivalent of the British Llandeilo formation of schists, flags, and lime- 
stone &c. Above these, but connected with them, is a considerable mass of 
shale or schist, chiefly characterized by Graptolites ; and this is covered by other 
limestones, which in Gothland are profusely charged with very many of the 
same species of Shells and Corals as are found in the limestones of Wenlock 
and Dudley. The whole of this series is capped, in the south of Gothland, by 
certain sandy strata, which are supposed to be meagre equivalents of the Lud- 
low rocks *. 
Whilst, however, the organic remains of the Silurian rocks of Sweden have 
been elaborately and ably described by various authors f , there is nowhere to be 
seen, in any one tract of that kingdom, the same concentrated succession of all 
these strata from their base upwards, or one natural section so clearly connecting 
the Lower and Upper Silurian, as is exhibited in Norway, and particularly in 
the territory of Christiania. There, as formerly described by myself, various 
strata, clearly divisible into 1 Lower ' and ' Upper ' Silurian through their cha- 
racteristic fossils, are regularly exhibited in a very small compass in the Steens- 
fiord, between the River Drammen and the Krokleven, to the west of Chris- 
tiania, where their uppermost member is conformably overlain by a great 
* See details of this succession, by Murchison in the ' Lethaea Suecica ' (1837) of Hisinger. G. 
and de Verneuil, Quart. Journ. Greol. Soc. Lond. Lindstrom's researches among the Gothland fossils 
vol. iii. p. 1. _ are well known to palaeontologists by his several 
t See ' Palseontologia Suecica,' pt. 1. In this memoirs on the Brachiopods, Operculated Corals, 
brief sketch, no justice can be done to the nume- &c. The ' G-sea Norvegica' of Keilhau is well 
rous works on the rocks and fossils of Sweden and known for its description of the lithological cha- 
Norway — countries which, from the time of Lin- racter of the various Norwegian rocks. But the 
naeus to the present day, have contributed so work which has completely worked out the pre- 
much to the progress of Natural History. In the cise relation of the component parts of the Silu- 
memoirs of the veteran Nilsson of our time, in rian rocks of Norway is that of M. Kjerulf. It 
those of Wahlenberg and Gyllenberg of past is from this publication that the data in the last 
years, and in the works of Love'n and Angelin, edition of ' Siluria ' were derived, which deter- 
which have more recently appeared, the fossil or- mined with so much exactness the similarity of 
ganic remains have received much illustration in the English and Norwegian Silurian rocks, 
addition to the knowledge formerly communicated 
