378 CAMBRIAN AND SILURIAN IN EUROPE. [XV. 



Bohemia, were marked by the first fauna ; although he, at the 

 same time, recognized this as distinct from and older than the 

 second fauna, discovered in the Llandeilo rocks, which Murchi- 

 son had declared to represent the dawn of organic life. Into 

 the reasons which led Barrande to include the rocks of the 

 first, second, and third faunas in one Silurian system (a view 

 which was at once adopted by the British Geological Survey 

 and by Murchison himself), it is not our province to inquire, 

 but we desire to call attention to the fact that the latter, by 

 his own principles, was bound to reject such a classification. 

 In his address before the Geological Society in 1842 (already 

 quoted in the first part of this paper), he declared that the 

 discussion as to the value of the term Cambrian involved 

 the question " whether there was any type of fossils in the 

 mass of the Cambrian rocks different from those of the Lower 

 Silurian series. If the appeal to nature should be answered in 

 the negative, then it was clear that the Lower Silurian type 

 must be considered the true base of what I had named the 

 protozoic rocks ; but if characteristic new forms were discov- 

 ered, then would the Cambrian rocks, whose place was so well 

 established in the descending series, have also their own fauna, 

 and the pakeozoic base would necessarily be removed to a 

 lower horizon." 



In the event of no distinct fauna being found in the Cam- 

 brian series, it was declared that " the term Cambrian must 

 cease to be used in zoological classification, it being, in that 

 sense, synonymous with Lower Silurian." (Proc. Geol. 

 III. 641, et seq.) That such had been the result of palaeon- 

 tological inquiry Murchison then proceeded to show. Inas- 

 much as the only portion of Sedgwick's Cambrian which was 

 then known to be fossiliferous was really above, and not be- 

 low, the Llandeilo rocks, which Murchison had taken for the 

 base of his Lower Silurian, his reasoning with regard to the 

 Cambrian nomenclature, based on a false datum, was itself 

 fallacious; and it might have been expected that when the 

 p.vcniincnt surveyors had shown his stratiirraphical error, 

 Murchison would have rendered justice to the nomenclature of 



