250 PROCEEDINGS OF THE AMERICAN ACADEMY 



Barrande insists on the great difference between tlie primordial fauna 

 of Bohemia and the second fauna. lie says, ''Nos etayes C et D j)eu- 

 veut elre cites, comme presentant la difference la plus absolue que Ton 

 connaisse entre les faunas de deux etages consecutifs." The cause of 

 this is the total absence of the Supra-Primordial fauna in Bohemia. 



Murchison hastened to profit by the excellent woik of Barrande. 

 and, before Si dgwick had finally decided to publish his " Synopsis," 

 — long since Munounced and only appearing in 1855, althou<ih 

 dated 1851 and 1852 in the Introduction, — IMurchison, always on the 

 qui vive, brought out a new and more pojjular edition, in octavo form, 

 of his " Silurian System." Without consideration, he not only boldly 

 placed in his " Lower Silurian " the formations of Caradoc and Llan- 

 deilo, or Bala Group of Sedgwick, but he went further, and placed there 

 also the " Lingula Hags " and the " Lougmynd or Bottom rocks," and 

 entirely sujipressed the " Cambrian." 



lie did eveu more ; the success of the term "Siluiian" caused him 

 to forget all prudence, and he included in his new edition of the " Si- 

 lurian System " all the paheozoic series under the unique title of 

 " Siluria " ; placing under this rubric of " Siluria " the primordial, 

 second, and third faunae, the Devonian, Carboniferous, and even all 

 the New Red Sandstone of Russia (Di/as and Trias), which he called 

 by the Russian name " Permian." In the second and third editions of 

 "Siluria," in 1859 and 18G7, the description of strata given always 

 increased in number, citing already the Jurassic and Cretaceous, and if 

 another edition had appeared, the whole stratigraphic series would 

 have passed under the title " Siluria," stopping oidy at the glacial 

 Quaternary. 



This excess of Siluria and Silurian brought on a reaction, and 

 Barrande himself gave the signal for it. 



Let us remember that forty years ago, or eveu thirty, communication 

 was not so easy as it is now, and that publications in one country and 

 in one hemisphere reached their destination in another with much 

 dilliculty, or not at all. 



So we must not be astonished if, notwithstanding the active and 

 persistent researches of Barrande to find all that had appeared upon 

 the primordial fauna and the rocks that enclose it, all the memoirs 

 and reports of Emmons had entirely escaped him. With a truly pro- 

 phetic intuition Barrande had successively announced the extension of 

 the primordial fauna he had established in Bohemia in 184G to Swe- 

 den, Norway, England, Spain, the Upper Mississippi, Braiutree near 

 Boston, Georgia, Texas, and Missouri. 



