808 SIR J. W. DAWSON Olf THE EOZOTC AIS^D PALEOZOIC 



observe that the Quebec group is not strictly an outer marginal for- 

 mation, but rather submargiual, and belongs to a period when the 

 principal area of coastal deposition of sediment from the north was 

 inland of the Acadian provinces, or between them and the main 

 American plateau, and separated from the outer ocean by a belt of 

 active volcanos. Its conditions of deposit and characteristic fossils 

 may fairly be compared with those of the Skiddaw and Arenig of 

 England *. The Ordovician series of Shropshire extending upward 

 from the Stiper Stones to the Caradoc is also a counterpart of the 

 Uuebec group t« 



Perhaps no term of comparison for these beds is more satisfactory 

 than that of the Graptolitic fauna j. This has been studied in the 

 case of the Canadian series with great care by Hall, whose monograph 

 on the Graptolites of Canada is a classical work, and subsequent 

 observations have ascertained several divisions between the Matane 

 series of the Lower St. Lawrence and the Utica §. The whole 

 subject has, however, recently been reviewed by Lap worth ||, in 

 connexion with material placed in his hands by the Director of the 

 Geological Survey of Canada, and his results are of the greatest 

 interest as indicating the precise correspondence in those truly 

 pelagic forms on the two sides of the Atlantic. They may be 

 summed up as follows, in ascending order : — 



Quebec Geoup op Lowee St. LawpvExce. 



1. Matane Beds %. — Grey, red and black shales, sandstones and 

 limestone, equivalent to Lower Calciferous of inland America and 

 Tremadoc of England. Characterized by Dictyonema sociale, Bryo- 

 grajjtus, ClonogvajDtus, &c. 



2. Levis Beds. — Dark shales, with sandstones and limestone- 

 conglomerates. Limestone-bands and dolomite. Characterized by 

 Phyllograptus, Tetragraptus^ Bidymograjytus, &c. Eemains of 

 siliceous sponges also occur in some places **. This corresponds to 

 the Chazy of inland America and the Ai'enig or Skiddaw of England. 



3. Marsouin Beds. — Shales, limestones, dolomites, and sandstone, 

 with Coenograptus^ Diplograjptus, &c. Equivalent to the Trenton 

 formation of interior America, including the Xormanskill Shales of 

 Hall, and to the Llandeilo formation of England. 



4. Utica Series. — Soft shales, often highly bituminous or carbon- 

 aceous, with Lejjtogrnjjtns, Diplograptus, &c. This is the Utica-Slate 

 formation of inland America, and corresponds to the Hartfell and 

 Caradoc group of England. 



* Hicks, ' Classification of LoTver Palseozoic Eocts,' 1881. 



t Lapworth, Geol. Magazine, 1887. 



j Mr. A. M. Ami, F.G.S., of the Geological Survey of Canada, has devoted 

 much labour to these fossils. 



§ Eeport Iledpath Museum, 1883. Paper bj- Mr. H. M. Ami, ' Ottawa Field 

 Club,' &c. 



II Transactions Eojal Society of Canada, 1886. 



^ Cape Rosier Zone of Lapworth. 



** Dawson and Hinde, Canadian Eecord of Science, 1888; also "Eedpath 

 Museum Notes," 1888. 



