266 C. SCHUCHERT — LOWER HELDERBERG-ORISKANY FORMATIONS 



This view differs from that of Freeh, for lie correlates F, and the F 2 

 Konieprussian with the Lower Helderberg and Oriskany. It seems to 

 the writer that in Bohemia there is no equivalent for the littoral Oris- 

 kany, and that between F, Konieprussian and F, Menian afaunal hiatus 

 exists. Etage F 2 Menian and G seem to conform to the American Scho- 

 harie grit and Corniferous. However, the writer does not insist on all 

 these correlations, but merely wishes to point out that the Lower Helder- 

 berg fauna finds its best representative in the Konieprussian of Bohemia. 

 The latter and etage F are now generally regarded by European stratig- 

 raphers as lowest Lower Devonic. 



Barrande long ago recognized a faunal resemblance between his etage 

 E and the Wenlock of England, although he also referred his etages 

 F, G, and H to the Siluric system. In Barrande's time, the Cambric 

 as a system was almost unknown, and even today Geikie* writes: 



"For myself, I repeat what I have said in previous editions of this text- book, 

 that the most natural and logical classification is to group Barrande's three faunas 

 [now Cambric, Ordovicic, and Siluric] as one system, which in accordance with 

 the laws of priority should be called Silurian." 



This is also the opinion of M Hebert,f F. Schmidt,! and De Lap- 

 parent. § If in this connection the fact is also borne in mind that the 

 Lower Devonic of Devonshire and of the Rhineland consists almost 

 wholly of sandy and slaty beds whose fauna at that time was little 

 known, thus contrasting with the well known, abundant, and almost 

 sequential faunas from the Primordial to etage H of Bohemia, it can be 

 partially understood why etages F, G, and H are correlated by Barrande 

 with the Upper Silurian. Again, if the great faunal resemblances or the 

 gradually modifying fauna of the etage E (Wenlock) into F and thence 

 (J and H are noted, another good reason appears ; and, finally, if remem- 

 bered that the upper limit of Murchison's Upper Silurian fauna was 

 essentially the Wenlock, and that the known Devonic fauna of his time 

 was practically that of the Middle Devonic, the argument is complete 

 for Barrande's reference of etages F, G, and H to the Silurian. These 

 facts formerty had, and still have their influence in America. At first 

 the Oriskany and Lower Helderberg were referred to the Silurian. After 

 De Verneuil and Sharpe's visit to America in 1847, the Oriskany was 

 referred to the Devonic (Hall, 1858), and this then came to be the gen- 

 erally recognized base for this system in the United States. || 



* Text-book of Geology, 1893, p. 727. 



f Bull. Soc. Gteol. France, 3 ser., vol. xi, 1882, p. 34. 



fQuar. .lour. Geol. Soc. London, vol. 38, L882, ]>. ."»!">. 



gTraite de Geologie, 3d ed., 1893. 



|! Shai'pe : Quar. Join-. Geol. Soc London, vol. iv, 1847, pp. 145-181. 



I).' Verneuil : Soc. Geol. de Frame, •_'<! ser., vol. iv, l,s47, pp. 646-709. 



Hall, Foster, ami Whitney's Kept, on Pake Superior, pt. ii, pp. '2*5-318. 



