248 THE CANADIAN NATCIlALISr. [A^ol. vil.. 



great thickness are excellent in qnallty. Bed No. 18 is one oT 

 the very few instances where a well characterized underelay was 

 found to lie below a bod of ll,i;iiite. 



Few recoj^nizable remiins of plants are found in this part of 

 the region in connection with the liii,iiites. Some beds, however, 

 and often those in close association with the li^nites, yield luol- 

 luscan remains, representini^' two species of P<iliedina or Vivljvini 

 at least tw<) oi' Mclaiiia, one Corhnht and several ^'/i/o-like bival- 

 ves. All these resemule those described by Meek and Ilayden, 

 from the Li<i;nite Tertiary further South, and the Cndmhi is 

 probably identical with their 6'. mftctrifoniiis, and indicates that 

 brajkish as well as fresh waters took part in the deposition of 

 the lower beds of this formation. 



Another peculiar feature in connection with the lignite deposits 

 is their tendency to burn away in sifii, and below the surface of 

 the ground. The beds become ignited by some prairie fire, or 

 '*he camp-fire of some Indian or trader, or it may be spontane- 

 ously (though this seems iniprob ible, as iron pyrites, the general 

 agent of spontaneous combustion in coals, is absent in these lig- 

 nites) ; and smoulder away I'or years, producing bivaks in the 

 edges of the bank by the caving in of superior beds, and giving 

 Tise to a material which is plentiful in many places, and resembles 

 a scoriaceous lava, but is reilly a species of clinker prmluced by 

 the fusion of the ashes of the lignite. 



In continuing westward, and after Inving crossed the region 

 of drift hills already mentioned as the Coteau de Missouri, the 

 Lignite formation is again represented in all the valleys and gullies 

 of the streams which now run southward, and form the upper parts 

 of the North Western tributaries of tho Missouri. Specially 

 good exhibitions of the rocks are to be seen in the first of these 

 large valleys, at a distance of ;U5 miles west of R 'd Uiver, and 

 also in another a few miles further west, whieh h;is been called 

 Pyramid Creek, from a remarkable pyramidiol hill formed by 

 the wearing away of the softer beds of the fornvition fi-om below 

 a layer of harder sandstone, a block of whidi has f^>rmed th3 

 capping of the hill. The beds are everywhere- nearly horizontal,. 

 showing merely local dips, and it does not ap^)ear that a great 

 thickness is represented by the whole of the- sections examined. 

 One locality is remarkable as showing the groatest development 

 of the lignit3 beds, and also for the abund mce of remiins of 

 plants in moderately good preservation. This is nearly 400' 



