of the Older Stratified Mocks of Devonshire and Corn'^all. 253 



Yorkshire and the hard siliceous fossil jrrits of Brora, proved 

 to be of the same age as the Oxfordshire ooMtes, are among 

 the many striking illustrations of a phaenomenon, of the pre- 

 valence of which, indeed, no stronger proof can be given, than 

 that geologically and zoologically considered, the massive clays 

 of the London basin are the same as the white limestones and 

 hard siliceous grits of Paris. 



\\\ applying, therefore, these analogies to Devonshire we 

 should say, that if the true mountain limestone (under its 

 ordinary aspect) thins out and is no longer traceable, we ounrht 

 to look for its equivalent in sandstone and shale : and in ac- 

 counting for the great development of many marine animals 

 which appear in the Devonian limestones, we have, a -priori^ 

 reason to expect the appearance of large stratified masses of 

 calcareous matter. 



If these views be confirmed by our best fossil conchologists 

 (of which we have little doubt), then will they have a most 

 important bearing upon the classification of the ancient rocks 

 of foreign countries, and we believe also of Ireland. In larf>-e 

 tracts of Europe, the first great series under consideration, (to 

 which one of us applied the word " system,") is supposed to be 

 wanting: but if this supposed absence be founded chiefly on 

 mineral characters, the representative of the system may still 

 be discoveied by its typical organic remains, though enveloped 

 in rocks like these of Devon and Cornwall, or in strata still 

 further removed from what we have been in the habit of re- 

 garding as the general type*. 



Conclusion. — We had no intention a few weeks ago of wri- 

 ting upon this subject. It is true that we had been gradually 

 changing some of our views respecting the age of the oldest 

 rocks of Devon and Coinwall (since the suggestion of our 

 friend Mr. Lonsdale before alluded to) ; and we should soon 

 have placed our opinion upon record before the Geological 

 Society. The publication, however, of the Report upon the 

 Geology of Devon and Cornwall, seen by one of the authors 

 for the first time within these few days, compels us, injustice 

 to our character f, (for it is now not merely a scientific, but also 



* We are led to believe, from the data already before us in the works of 

 foreign authors, that the old red system will be found in the provinces of 

 Russia and the Scandinavian countries, as well as in Poland and Germany. 

 M. Elie de Beaumont has recently written to one of the authors, and ap- 

 proving of the establishment of the old red sandstone as a separate 

 " System", he says that he has no doubt it will be largely found on the 

 continent. 



t At the conclusion of a note affixed to p. 130 of Mr. De la Beche's Re- 

 port on the Geology of Cornwall and Devon occur the following words : 

 " He," the Rev. D. Williams, " observes, that he stated the fact of the car- 



