372 
SILUKIA. 
[Chap. XV. 
when he enters upon the territory around Prague, and there sees, under the 
guidance of my eminent friend M. Barrande, a most complete and symmetrical 
exposure of the whole Silurian System, whether as respects the clear order of 
the strata, or a vast abundance of organic remains. 
The geologist who would form an adequate idea of the relations of this 
'Bassin Silurien,' so admirably developed by that author, must traverse the 
tract as I have done with him, from Przibram and Ginetz on the south-east, to 
Skrey on the north-west, or visit the environs of Beraun. He will then at once 
recognize the truthfulness and accuracy of the divisions which have been esta- 
blished after a most indefatigable and persevering study of the rocks and their 
organic remains during the last twenty-seven years. The simple and regular form 
of this basin, and the order in which its concentric deposits are arranged, have 
enabled its first true explorer to ascertain the existence of three characteristic 
faunas, containing eight local stages, into which Barrande divides what he has 
there proved to be the ' Silurian System.' (See the preceding diagram*.) 
Just as in the British Isles, the lowest fossil-bearing strata, c of the section, 
repose on vast masses of conglomerates, grits, and crystalline schists, b, a. These, 
which are of Cambrian age, rest upon gneiss and granitic rocks, which, in 1862, 1 
classed as Laurentian. The argillaceous schists, c, the lowest in which fossils 
occur, contain Barrande's 'Faune Primordiale.' This ' Primordial' Silurian 
fauna is specially characterized by Trilobites of the genera Paradoxides, Cono- 
cephalus, Ellipsocephalus, Sao, and Agnostus ; and it also contains a rare 
Orthis, a few Cystidea, and some species of Pteropods belonging to the genus 
Theca. According to the opinion of M. Barrande, in which I entirely agree, this 
zone is represented (as before said, pp. 40, 45, &c.) by the rocks containing Lin- 
gula, Agnostus, Conocephalus, and Paradoxides in North and South Wales, and 
also by those which in the south-west flank of the Malvern Hills contain the 
Olenus ; whilst, as has already been noted, Olenus, together with Paradoxides and 
Agnostus, are typical of the lowest band in which animals have yet been found 
in Norway (see p. 349, 2nd section : this zone represents also the Alum-slates, 
or ' Regiones A, B' of Angelin). The large species of Paradoxides in Bohemia 
also belong to the same ' Primordial ' group. To the same epoch must also be 
referred the similar forms which have been described, by Dr. Dale Owen, Pro- 
fessor W. Rogers, and others, as characterizing the lowest Silurian rocks of the 
eastern coast of North America. 
On reexamining, in 1862, the crystalline rocks which form the central nu- 
cleus of Germany in Bohemia and Bavaria, I could scarcely fail to perceive that, 
just as in the north-west of Scotland, they there formed a true representative 
of the Laurentian System, as proved by infraposition. In fact I reentered that 
region already disposed to believe that this equivalent was to be recognized 
in the gneiss and granite described by Barrande as underlying his general 
ascending series. 
In exploring the Bavarian or western portion of this ancient chain, I was also 
furnished with the instructive geological map of Dr. C. Giimbel of Munich ; and 
with that in hand, it at once seemed to me that the ascending order from a 
* Though the conclusions are stated briefly in key he could not direct his workmen, M. Bar- 
the text, I must be allowed to say that they could rande mastered the difficulty, and made himself 
have been arrived at only through intense labour a Bohemian scholar in order to become a thorough 
and unwearied research, as well as by the liberal geological expounder of these rocks. His Silurian 
employment of Bohemian workmen. The last collections are certainly more interesting than 
twenty-seven years have been occupied in un- those ever made before by any one individual; 
ravelling this grand and rich Silurian fauna. To whilst the evidences of faithful scrutiny and of a 
most persons the acquisition of the Bohemian or philosophical spirit which pervade all the pages 
' Czeck ' language might have been an insur- of his great work are, I know, duly appreciated 
mountable barrier ; but, finding that without this by every geologist and naturalist. 
