WiuclielL] '-'-' [March 5, 



ism existing between American and European jjaleozoic formations. ^^ Tliis 

 paper was translated and somewhat condensed by Professor Hall for pub- 

 lication in America. ^° 



Professor'Hall's translation is accompanied by criticisms and additions, ^i 

 One of the results of de Yerneuil's studies was to lower the base of the 

 Devonian system from the bottom of the Portage group where it had been 

 placed by Conrad, to the bottom of the Oriskany sandstone, and to fix 

 the summit above the Catskill group. He recognized the prolongation of 

 the Portage and Chemung groups into Ohio, biit did not detect them in 

 Indiana, Kentucky, and Tennessee ; though Prof. Hall in his notes upon 

 the paper, was inclined to recognize them in Indiana above his and Owen's 

 "sub-carboniferous." The upper, or fossiliferous portion of the Waverly 

 series was regarded by de Verneuil as falling within the limits of the car- 

 boniferous system. The Black Slate of the West was identified with the 

 Genesee Shale of New York. These conclusions are fortified by extended 

 jjaleontological comparisons. 



Professor Hall in his commentary ui3on this elaborate paper, seems to 

 oscillate between tv/o opinions. He insists at one time upon the Silurian 

 relationships of the Hamilton, Portage and Chemung, and the broad 

 lithological and paleontological gap intervening between the Chemung 

 and the Catskill, 22 intimating that there is the place to draw the systemic 

 lines ; while at another time he asserts that the Chemung is more inti- 

 mately "related to the Carboniferous sandstones of the West than the 

 Hamilton group of New York " 23 — that "there is no well defined line of 

 separation between the Chemung rocks of New York, and the sandstones 

 of Ohio and Indiana, which contain carboniferous fossils" — and that 

 ' ' the error of American geologists w ho have attempted to compare our 

 formations with those of Europe, has been, in this instance, that of regard- 

 ing the great Carboniferous limestone as forming the basis of that system, 

 including all the strata below it in Devonian and Silurian."^^ 



In 1848 Mr. Murray, of the geological survey of Canada, made an ex- 

 amination of black bituminous shales on the south-east shore of Lake 

 Huron at Kettle Pt., and described them25 under the head of " Hamilton 

 group," remarking that they contained LingiUa, but "neither of the two 

 species represented by Mr. Hall as belonging to the Genesee slate." Mr. 

 Mvirray adds that "no trace of the sandstones [of the Portage and Che- 

 mung groups] . . . has yet been met with in western Canada." 



19 " Sur le parall§li8me des depots pal6ozoicLues de I'Amerique Septentrionale avec ceux de 1' 

 Europe ; suivie d' un tableau des 6speces fossiles communes aux deux continents, avec 1' indication 

 des Stages od elles se rencontrent, et terminfe par un examen critique de chaque de oes 6sp6ces." 

 Bulletin de la Soc. Geol. de France, 2me Ser. Tome, iv, p. 646. 



™ Am. Jour. Soi. and Arts, [2] vol. v. pp. 176 and 359 and vol. vii. pp. 4.5 arid 218. 



21 See further critical remarks by Sharpe, "On the Paleozoic Rocks of N. A.,'' in Quar. Jour. Geol. 

 Soc. Lond., Aug. 1848, and a paper by Mr. Bile de Beaum,ont, entitled " Hole sur les syst6mes de 

 Montagues les plus ancieus de 1' Europe." 



22 Amer. Jour. Sci., [2] v. .367, Note ; vii, 46, Note .3 and p. 231. He had previously pointed out the 

 break below the Catskill. Pal. N. Y., vol. 1, intrpd. p. xvi. 



23 Amer. Jour. Sci., [2] vii, p. 46, Note (a,) 

 2' Amer. Jour. Sci , [2] vii, 45, Note. 



2» Keport of Progress, 1848-9, p. 24. 



