406 THE CAMBRIAN. [bull. 81. 



out the perimeter of the great western area under consideration. From the north- 

 west border of North Carolina it sweeps in a broad belt across Virginia to the junc- 

 tion of the Shenandoah and Potomac. Thence traversing Maryland, it passes 

 through Pennsylvania by Harrisburg, on the Susquehanna, and Belvidere, on the 

 Delaware, accompanied up to this point by the underlying sandstone. Diminished in 

 its thickness, it thence crosses New Jersey, and reaching Poughkeepsie it passes up 

 the valley of the Hudson and Champlain, keeping to the east of the river and the 

 lake, and attains the neighborhood of Missisquoi Bay. Entering Canada, it pro- 

 ceeds towards Quebec, and it reaches the vicinity of that fortress; but I am not yet 

 aware of the precise spots at which it is visible in its course thither, farther than 

 that I have been informed a stratified limestone answering its condition is quarried 

 and burned in the Seignory of St. Hyaciuthe, east of the Yamaska River. 1 



He states that the city of Quebec does not stand on this limestone, 

 but it is found below the city on the north shore of Beauport and 

 further down the river to Cape Tourmeut. Following up the valley of 

 tlie St. Lawrence, it is found to run along the foot of a range of syen- 

 itic hills, and it leaves the river iu the vicinity of Montreal and again 

 appears in the Ottawa Basin. He then describes its extension south 

 along the valley of Lake Champlain, and west through the valley of 

 the Mohawk and Black River and north of Lakes Ontario, Huron, aud 

 Michigan, to Wisconsin, following thus the correlation made by Hall. 



NEWFOUNDLAND. 



The extension of the Canadian nomenclature to Newfoundland was 

 the work of Messrs. Logan and Billings. In tracing the Paleozoic for- 

 mations down the St. Lawrence River from Montreal, Logan found that 

 a series of sandstones occurs beneath the Calciferous sandrock, which 

 was well recognized beneath the Trenton limestone. The sandstones 

 rested u neon form ably upon the subjacent Archeau. A long interval 

 exists between these exposures and those on the north side of the 

 Straits of Belle Isle, where sandstones and limestones are superjacent 

 to the Archean. In his first expression of opinion he calls the sand- 

 stones the Potsdam, from their stratigrapliic position and lithologic 

 character. When the fossils which were obtained from the associated 

 limestones were examined by Mr. Billings and found to be identical 

 with those that he had referred to the Lower Potsdam in Vermont, the 

 strata on the north side of the Straits of Belle Isle were referred with- 

 out reserve to the Potsdam horizon, and those occupying a similiar 

 position on the west of Newfoundland were also similarly referred. 2 



When correlating the Lower Cambrian sandstones and slates of 

 northern Vermont with the limestones and sandstones of the north 

 shore of the Straits of Belle Isle, upon the lithologic and paleoutologic 

 similarities between the two deposits, Mr. E.Billings states that although 

 860 miles distant from each other there can be little doubt that they 

 are of the same age. 



1 [Account of general structure of an extended area in North America.) Geol. Survey Cana'la, Re- 

 port of Progress for 1843, 1845, p. 8. 



2 Geological Survey of Canada ; Report of Progress from its commencement to 1863, pp. 97, 288, 

 289, 864, 865. Montreal, 1863. 



