212 THE CANADIAN NATURALIST. [Vol. vif... 



They are well exposed in vertical cliffs at the Grand Rapids, and 

 they likewise occupy the whole of the western shores of Lake 

 Winnipeg', extending in a south-easterly direction for 350 miles- 

 to Fort Garry. Some of the beds would, I think^ afford good. 

 slabs for lithographic purposes, while from others a rich hnrvest 

 of fossils awaits the collector. Between these limestones and th& 

 eastern slopes of the second prairie level, on the shores of Lake- 

 Winnipegosis and Manitoba, somewhat similar limestones have,. 

 I believe, been observed, holding fossils of Devonian age ; so that 

 we have in the great lowMying region which constitutes the first 

 prairie level, a large pirt of which is occupied by the waters of 

 lakes Winnipeg, Winnipegosis, and Manitoba, the eastern out- 

 crops of a thick series of Devonitn :ind Silurian strata, and it 

 becomes an interesting question to deternjine how these easterrti 

 Palaeozoic rocks are related to those of more disturbed and altered 

 aspect which rise from beneath the coal-bearing Cretaceous forma- 

 tions at the sources of the Saskatchewan and there form the 

 eastern slopes, as well as many of the higher summits of the 

 Rocky Mountains. We know at present little or nothing respect- 

 ing the total thickness of the Cretaceous rocks which are spreadl 

 over a breadth of 1000 miles between Manitoba atid the Rocky 

 Mountains, neither do we at present know to what extent the 

 upper part of the series, which is supposed to occupy the surface- 

 from the 100th meridian westward to about the 1 12th. may or 

 may not be underlaid by the supposed older beds, with their 

 associated seams of brown coal and iron ore. The general scar- 

 city and the poor quality of the timber over hundreds of miks 

 of country, renders it, however, a matter of the very groates-t 

 importance in connection with the future settlement of a large 

 portion of the " Fertile Belt," and with the opening it up either 

 by land or by water steam transport, to ascertain where and at 

 what depth beneath the surface coal could be procured which 

 would be available for domestic purposes as well as for the supply 

 of railroads and steamboats. Surface examination and survey 

 alone, however minute, cannot be expected to lend much aid to 

 the solution of this question, owning partly to the almost universal 

 covering of superficial deposits, and partly also to the extreme 

 flatness of the strata and the comparatively few points where 

 they can be observed in natural exposures. It would, I think, 

 not be difficult, however, to settle this point by means of a series 

 of bore holes mide at intervals along the valley of the Saskatche- 



