14 ASSINNIBOINE AND SASKATCHEWAN EXPEDITION. 



the white portion is extremely brilliant, of a pure white, 

 and very siliceous ; it would form an excellent material 

 for the manufacture of glass. Forms, coloured brown, 

 often pervade the white sandstone, and appear to re- 

 semble fucoids and corals replaced by brown ochreous 

 sand. 



No. 4. Eighteen feet of limestone, perfectly horizontal, 

 very hard, and breaking off the cliff, where the soft sand- 

 stone has been weathered away, in huge rhomboidal slabs, 

 eight to twenty-five feet in diameter, and four to ten 

 inches thick. 



The surface of the limestone shows silicified shells and 

 corals : among the shells an Orthoceras nine inches in 

 diameter was seen, with fossils belonging to the genera 

 Bhynchonella and Tetradium. This formation is equiva- 

 lent to the Chazy of New York and Canada, and con- 

 sequently lies near the base of the Low^er Silurian Series. 



In the shingle immediately below the cliff, many fine 

 Orthoceratites were found, with a large Maclurea, and 

 Catenipora eschar oldest 



Limestone forms the west coast for some miles south 

 of Big Grindstone Point, where we arrived in the evening. 

 This part of Lake Winnipeg is very beautiful, resembling, 

 in many pleasing particulars, the scenery on the justly 

 celebrated Lake Simcoe, Canada West, near the Narrows, 

 where wooded islands rising from the lake in clusters and 

 rows, are suggestive of tranquil summer retreats. Between 

 Grindstone Point and Deer Island, the lead showed sixty 

 feet of water. It is the great fishing-ground of some of 

 the bands of Indians who make this part of the lake their 



* For tlie determination of the fossils from this and other localities in the 

 region about Lake Winnipeg, Manitobah, &c, I am indebted to E. Billings, 

 Esq., F.G.S., Palaeontologist to the Canadian Geological Survey. 



