422 CAMBRIAN AND SILURIAN IN NORTH AMERICA. [XV. 



divided into several groups, of which the first, including the 

 Primal, Auroral, and Matinal, is declared to be the near repre- 

 sentative of " the European palaeozoic deposits from the first- 

 formed fossiliferous beds to the close of the Bala group ; that 

 is to say, the proximate representatives of the Cambrian of 

 Sedgwick." A second group embraces the Levant, Surgent, 

 Scalent, and Pre-Meridional. These are said to be " the very 

 near representatives of the true European Silurian, regarding 

 this series as commencing with the May Hill sandstone." The 

 Levant division is further declared to be the equivalent of the 

 sandstone just named ; while the Matinal is made to corre- 

 spond to the Llandeilo, Bala, or Upper Cambrian ; the Auroral 

 with the Festiniog or Middle Cambrian ; and the Primal with 

 the Lingula flags, the Obolus sandstone of Russia, and the Pri- 

 mordial of Bohemia. 



The reader of the last few pages of this history will have 

 seen how the Silurian nomenclature of Murchison and the 

 British geological survey has been, through Lyell, De Verneuil, 

 and the Canadian survey, introduced into American geology in 

 opposition to the judgment, and against the protests of James 

 Hall and the Messrs. Rogers, the founders of American palaeo- 

 zoic geology. 



Three points have, I think, been made clear in the first and 

 second parts of this sketch : first, that the series to which the 

 name of Cambrian was applied by Sedgwick in 1835 (limited 

 by him as to its downward extension, in 1838) was coextensive 

 with the rocks characterized by the first and second faunas ; 

 second, that the series to which the name of Silurian was 

 given by Murchison in 1835 included the second and third 

 faunas, but that the rocks of the second fauna, the Upper 

 Cambrian of Sedgwick, were only included in the Silurian 

 system of Murchison by a series of errors and misconceptions 

 in stratigraphy on the part of the latter, which gave him no 

 right to claim the rocks of the second fauna as a lower mem- 

 ber of his Silurian ; third, that there was no ground whatever 

 for subsequently annexing to the Silurian of Murchison the 



