GEOLOGY. 251 



which has been previously applied to the lowest known deposits of 

 England, Wales, and Ireland. Though we must not dogmatize and 

 affirm that these fundamental deposits were in the pristine state ab- 

 solutely unfurnished with any living things (for Logan and Hunt, in 

 Canada, have suggested that there they indicate traces of the former 

 life), we may conclude, that in the highly metamorphosed condition 

 in which they are now presented to us in North-western Britain, and 

 associated as they are with much granite and hornblendic matter, 

 they are, for all purposes of the practical geologist, " azoic rocks." 

 The Cambrian rocks, or second stage in the ascending order, as seen 

 reposing on the fundamental gneiss of the north-west of Scotland, 

 are purple and red sandstones and conglomerates forming lofty 

 mountains. 



They have afforded some few traces of organic life : the " Old- 

 halmia," possibly an Alga ; some worn tracks, and the trace of an 

 obscure crustacean. 



The Highland rocks of this age, as well as their equivalents, the 

 Huronian rocks of North America, have as yet afforded no trace 

 whatever of former life. And yet, such Cambrian rocks are in parts 

 of Wales, and especially in the lofty mountains of the north-west- 

 ern Highlands, much less metamorphosed than many of the crystal- 

 line 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 Pri- 

 mordial Zone of Mr. Barrande is the oldest fauna of his Silurian 

 Basin in Bohemia. 



In the classification adopted by De la Beche and his associates, 

 the Lingula Flags (the equivalent of the " Zone Primordial " of Bar- 

 rande) 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 Dale, Owen, and others, in the United 

 States ; and by Sir W. E. Logan, Sterry Hunt, and Billings, in 

 Canada. 



In the last year Mr. Barrande has most ably compared the North 

 American Taconic group of Emmons with his own primordial Si- 

 lurian fauna of Bohemia, and other parts of Europe ; and it is quite 

 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, etc., as well as of the lower portion of the Quebec 

 rocks, with their Conocephalus, Axionellus, etc., described by Logan 

 and Billings. Of the crystalline schists of Massachusetts, containing 

 the noble specimen of Paradoxides described by W. B. 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 in- 

 verted position in some cases, and in others be altered into crystal- 

 line rocks. 



In an able review of this subject, Mr. T. Sterry Hunt thus ex- 

 presses himself: " We regard the whole Quebec group, with its 



