122 THE CAMBRIAN. [bull. 81. 



of Bichinond Bay. The observations upon which this identification is 

 based were made by Dr. Kobert Bell, who explored the east coast of 

 Hudson Bay in 1877. He names the series the Manitounuck group, 

 correlating it with the Nipigon series north of Lake Superior. By com- 

 bining the sections of slates and sandstones he obtains a thickness of 

 2,800 feet for the entire section on this part of the coast. 1 



Keferences to the occurrence of rocks of supposed Cambrian age on 

 Lakes Mistassini and Mistassinis are made by Mr. A. P. Low in his 

 report on the Mistassini expedition. The limestones, owing to the 

 absence of any fossil remains, have been referred to the Cambrian hori- 

 zon on account of their lithologic resemblance to Cambrian rocks of the 

 east side of James Bay. 2 



A map of Lake Mistassini accompanies the report, on which the 

 boundary between the Laurentian and supposed Cambrian formations 

 is traced. 



Dr. George M. Dawson tabulates the formations j he refers to the 

 Cambrian in Ontario and Quebec as follows : 3 



3&. Sillery and Levis. 



3a. Calciferous. 



2c. Upper and Lower Potsdam. 



26. Keweenian. 



2a. Animikie. 



SOUTHERN APPALACHIAN DISTRICT. 



The Southern Appalachian district includes the outcrops of strata 

 referred to formations of the Cambrian group in northern and central 

 New Jersey, southeastern and southern central Pennsylvania, western 

 Maryland,Yirginia, and North Carolina, eastern Tennessee, northwest- 

 ern Georgia, and northeastern Alabama. 



NEW JERSEY. 



In a table showing the geologic succession of the lower Secondary 

 or Appalachian rocks as they occur in New Jersey, Prof. Rogers 4 

 places as No. 1 of the series of formations a compact and very quart- 

 zose sandstone, of light bluish gray color, approaching to white. He 

 discovered the formation in only three or four small isolated areas along 

 the western outcrops of the Primary rocks. Prof. Cook refers to this 

 sandstone lying upon the gneiss as the u Potsdam sandstone " as known 

 in New York. It is only a few feet in thickness. 5 In a subsequent report 

 a sketch is given of a section at Franklin Furnace, which shows the sand- 



1 Report on an exploration of the east coast of Hudson's Bay, 1877. Geol. Surv. Canada, Rep. Prog, 

 for 1877-78. 1879, p. 17C 



2 Report of the Mistassini Expedition, 1884-'85. Geol. and "Nat. Hist. Surv. Canada, new ser., vol. 1, 

 1885, p. 31D. 



•Macfarlane James: An American Geological Railway Guide. Seconded., 1890, p. 58. 

 4 Description of the Geology of the State of New Jersey, heingafinal report. Philadelphia, 1840, p. 45. 

 6 Report of Prof. George H. Cook upon the geological surveyof New Jersey, and its progress dnring 

 the year 1863. 1864, p. 6, par. 9. 



