306 ASSINNIBOlNE AND SASKATCHEWAN EXPEDITION. 



lower strata, forming with other materials the broad ex- 

 panse of prairie deposit of the west." * 



It is very gratifying to know that on the western side 

 of the great basin between the Laurentides and the 

 Rocky Mountains, and within the limit of the Saskat- 

 chewan valley, the Carboniferous series are represented. 

 Sir Roderick I. Murchison, in his address at the Anniversary 

 Meeting of the Royal Geographical Society, in referring 

 to the splendid results of the Palliser Expedition, says, 

 " Thus in addition to the determination of latitude, longi- 

 tude, and the altitude of the mountains and two of their 

 passes, Dr. Hector presents us with a sketch of the 

 physical and geological structure of the chain, with its 

 axis of slaty sub-crystalline rocks, overlaid by limestones 

 of Devonian and Carboniferous age, and flanked on the 

 eastern face by Carboniferous sandstone, representing, 

 probably, our own coal fields, the whole followed by those 

 Cretaceous and Tertiary deposits which constitute the sub- 

 soil of the vast and rich prairies watered by the North 

 and South Saskatchewan, and their affluents." f 



Ammonites. 



FROM M C KENZIE'S RIVEK, PROBABLY FROM JURASSIC ROCKS. 



[The two Ammonites from McKenzie's River, are not 

 alone sufficient to determine the age of the rock from 

 which they were obtained ; the larger one bears consi- 

 derable resemblance in form and general appearance to 

 several Jurassic species though they may belong to the 

 Cretaceous epoch. It is very desirable that a good 

 series of specimens should be obtained from this remote 



* Remarks on the Tertiary and Cretaceous Formations of Nebraska, &c. 

 &c, "by F. B. Meek and F. V. Hayden, M.D. 



f Page 318, Proceedings of the Royal Geological Society, vol. iii. No. 4. 



