Chap. XV.] 
PEIMOEDIAL SILUEIAN ZONE. 
373 
fundamental gneiss upwards was the same as in North America and North 
Britain. Hence, on my return, I announced to my colleagues in England that 
the two great zones of rock which Dr. Giimbel named the Bojic (or Bavarian) 
and the Hercynian Gneiss seemed to me to constitute one great system of enor- 
mous thickness, and that, judging from the overlying formations, it must be 
truly Laurentian *. 
In fact these gneiss rocks in Bavaria are separated from the ' Primordial Zone ' 
(Etage c) of Barrande, or true base of the Silurian strata, in the first place by 
large masses of micaceous and chloritic schists with quartzites, and next by a 
very great thickness of clay-slate (Ur-Thon-Schiefer), which is directly followed 
by the ' Primordial ' Silurian zone. This position necessarily places these 
schists and slates (Stages a and b) precisely in the same stratigraphical arrange- 
ment as the British Cambrian of the preceding pages. 
In the following year Dr. Giimbel discovered Eozoon Canadense in the 
marbles of the band of gneiss which he considers to be the younger (but 
which is also according to him analogous to the older) Laurentian of Logan, 
and thus he completed the proofs of the age of these gneissic deposits. 
With them, indeed, he classes the overlying micaceous and chloritic schists 
as also Laurentian. Judging, however, of these rocks by comparison with our 
British series of like age, I am of opinion that they are simply the meta- 
morphosed portions of the Cambrian or slaty rocks which in Bavaria, as in 
Anglesea and North Wales, have been altered by the protrusion of granite. 
However that may be, it is in the clay-slates, which underlie everything of 
Silurian date, that Dr. C. Giimbel has detected another species of Foraminifer, 
which he has named Eozoon Bavaricum. Dr. A. Fritsch, of Prague, had 
already observed certain Annelide-tubes in the quartzose schists of the 
' Etage a ' of Barrande, near Prague f. 
Having for the last quarter of a century grouped the ' Primordial Zone ' as the 
base of the Silurian System, I am greatly indebted to M. Barrande for the 
important evidence which substantiated the intimate connexion of that zone 
with the rest of the Silurian formations. 
Lying above all these enormous masses of clay-slate, the ' Primordial Zone ' J 
was discovered to the south of Hof, but presenting a remarkable agglomeration of 
fossils which, in the hands of M. Barrande, proved to be ordinary Lower Silurian 
types, but with a predominance of forms specially characteristic of the ' Primor- 
dial Zone.' Thus Calymene, Cheirurus, with Orthis and Cystidea of the Llan- 
deilo and Caradoc formations, were commingled with many Conocephali, Oleni, 
and Lingulse of the ' Primordial Zone.' The true coexistence of those types (as 
M. Barrande himself showed me) in the same hand-specimens was to me, 
therefore, the most satisfactory proof I ever obtained that I had judged rightly, 
after many wide surveys, in classifying the ' Zone Primordiale,' or its equivalent 
the Lingula- and Conocephalus-flags of Wales, as the true base of the Silurian 
System of life. 
* See Quart. Journ. G-eol. Soc. vol. xix. p. 359. fossils brought from the same place, which were 
t G-eol. Mag. vol. iii. p. 431. noticed by Geinitz ('Verstein. Grauwacke-Forma- 
l The position of this band of the 'Zone Pri- tion,'vol. ii.p. 25). In 1860 M. Barrande urged the 
mordiale 'was given by Professor Giimbel in a German geologists to explore the site, and thereon 
section which I brought out in a memoir on the Professor Wirth, of Hof, made the collection in 
general succession in Bavaria from the Laurentian question, which he remitted to Dr. Giimbel, who 
gneiss up to the Devonian and Carboniferous rocks transmitted it to M. Barrande for determination, 
of Hof (Quart. Journ. Geol. Soc. vol. xix. p. 354). In 1863 M. Barrande, in a note on the geology of 
The process by which this important point was the environs of Hof, explains these points in rela- 
established was as follows : — In 1851 M. Barrande tion to the discoveries of Casiano di Prado in 
discovered fossils of this zone in the collections of Spain (Bull. Geol. Soc. France, vol. xx. p. 476, 
Count Miinster, and then visited the ground to vol. xvii. p. 543). 
mark their position. In 1852 he observed similar 
