BRITISH ASSOCIATION MEETING. 
431 
rocks of North America, have as yet afforded no trace whatever of former life. 
Ajid yet, such Cambrian rocks are in parts of the Longmynd, and specially in 
the lofty raoiintanis of the North Western Highlands, much less metamorpliosed 
than many of the crystalline rocks which lie upon them. Rising in the scale of 
successive deposits, we find a corresponding rise in the signs of former life on 
reaching that stage in the earlier slaty and schistose rocks in which animal 
remains begin clearly to show themselves. Thus, the Primordial Zone of M. 
Barrande is, according to that eminent man, the oldest fauna of his Silurian 
Basin in Bohemia.* 
In the classification adopted by Sir Henry De la Beche and his associates, 
the Lingula Elags (the equivalent of the Zone Primordiale of Barrande) are 
similarly placed at the base of the Silurian System. This Primordial Zone is 
also classed as the Lowest Silurian by De Verneuil, in Spain ; by James Hall, 
Bale Owen and others, in the United States ; and by Sir W. Logan, Sterry 
Hunt, and BiUings, in Canada.f 
In the last year, M. Barrande has most ably compared the North American 
laconic group of Emmons| with his own primordial Silurian fauna of Bohemia, 
and other parts of Europe ; and although that sound palaeontologist, Mr. James 
Hall, has not hitherto quite coincided with M. Barrande in some details, § it is 
evident that the primordial fauna occurs in many parts of North America. 
And as the true order of succession has been ascertained, we now know that 
the Taconic group is of the same age as the lower Wisconsin beds described 
by Dale Owen, with their Paradoxides, Dikelocephalus, &c., as well as of the 
lower portion of the Quebec rocks, with their Conocephalus, Axionellus, &c., 
described by Logan and Billings. Of the crystalline schists of Massachusetts, 
containing the noble specimen of Paradoxides described by W. Rogers, and of 
the Vermont beds, with their Oleni, it follows that the Primordial Silurian 
Zone of Barrande (the lower Lingula-flags of Britain) is largely represented in 
North America, however it may occupy an inverted position in some cases, and 
in others be altered into crystalline rocks. 
In determining this question due regard has been had to the great convul- 
sions, inversions, and breaks, to which these ancient rocks of North America 
have been subjected, as described by Professors Henry and W. Rogers. 
* I learn, however, that in Bohemia, Dr. Fritsch has recently discovered strata 
lying beneath the mass of the Primordial Zone of Barrande, and in rocks hitherto 
considered azoic the burrows of annelide animals similar to those of our own 
Longmynd. 
+ In completing at his own cost a geological survey of Spain, in which he has 
been occupied for several years, and in the carrying out of which he has determined 
the width of the sedimentary rocks of the Peninsula (including the Primordial 
Silurian Zone, discovered by that zealous explorer, M. Casiano de Prado), M. de 
Verneuil has in the last few months chiefly examined the eastern part of the king- 
dom where few of the older palaeozoic rocks exist. I am, however, informed by 
him, that Upper Silurian rocks with Cardiola interrupta, identical with those of 
France and Bohemia, occur along the southern flanks of the Pyrenees, and also 
re-occur in the Sierra Morena, in strata that over-lie the great mass of Lower 
Silurian rocks as formerly described by M. Casiano de Prado and himself. The 
Bouthera face of the Pyrenees, he further informs me, is specially marked by the 
display of mural masses of Carboniferous strata, which, succeeding the Devonian 
rocks, are not arranged in basin shape, but stand out in vertical or highly inclined 
positions, and are followed by extensive conglomerates and marls of Triassic age, 
and these by deposits charged with fossils of the Lias. 
t The Silurian classification was proposed by me in 1835, and in the following 
year, 1836, Dr. Emmons suggested that his black shale rocks, which he called 
Taconic, were older than any I described. 
§ Nor are the writings of the Professors W. B. and H. D. Rogers in unison with 
the opinions of the .ora here cited. 
