REPORT OF THE STATE PALEONTOLOGIST 1902 953 



end of the Island of Orleans. This character is maintained with 

 great uniformity for the entire distance west of Marsouin, 

 though at certain points the Sillery sandstones and red and 

 green shales representing division 4 are more highly developed 

 than at others. The rocks of this section would, therefore, both 

 on the evidence of Professor Lapworth from the fossils, and 

 from the comparison with the stratigraphical sequence of the 

 Cape Rouge rocks, belong to a portion of the Cambrian system, 

 probably representing the upper and middle divisions of that 

 system, while the overlying Levis graptolitic shales and lime- 

 stone conglomerates would represent the lower portion of the 

 Ordovician or Cambro-Silurian system. 



Dr Ells refers thus, on the evidence afforded by the strati- 

 graphy and the graptolites, determined by Lapworth, the Sillery 

 rocks (divisions 1, 2, 3 and 4) to the Cambric, and the Levis 

 beds (division 5) to the lower Beekmantown. 



Mr Walcott, in his review of Dr R. W. Ells's report 1 

 takes exception to some of Dr Ells's conclusions, as we see 

 from his quoted statements: 



The Cape Rosier Dictyonema sociale zone is regarded 

 as the lowest of the graptolitic zones, and to indicate the 

 horizon of the Tremadoc terrane of Great Britain. The Cape 

 Rosier beds are referred to the Upper Cambrian by Professor 

 Lapworth and Dr Ells, but, with our present knowledge of the 

 Cambrian in America, I would refer them to the Lower 

 Ordovician or to the lower Calciferous. The occurrence of the 

 typical Calciferous fauna within one hundred (100) feet of the 

 base of the Levis series, at St Joseph de Levis, points very 

 strongly to considering the graptolitic fauna of the Upper 

 Sillery to be of Calciferous age, if a comparison is made with 

 the Phillipsburgh section. 



Dr Ells refers the Sillery series to the Cambric, and in this 

 I mainly agree with him, except that the upper portion is evi- 

 dently a passage series between the Cambric and Lower Siluric. 

 On lithologic and stratigraphic evidence the line would be 

 drawn at the summit of the red shales. On paleontologic evi- 

 dence, as furnished by the graptolites, I would include the upper 

 portion of the Sillery red and green beds in the Lower Siluric, as 

 I think they are above the typical Potsdam zone of America. 



While we agree with this distinguished author in referring 

 the upper part of division 4, containing P h y 1 1 o g r a p t u s 



'Am. Jour. Sci. ser. 3. 1890. 39:113. 



