246 THE CANADIAN NATURALIST. [Vol VU. 



the first elevation towards the Cotoau de Missouri, or region of 

 high and broken ground which separates the waters draining by 

 the Souris and Saskateliewm Rivers to Hudson's Bay, 'Vom 

 those forming the northern tributaries of the Missouri River, 

 and falling at last into the (Julf of Mexico. Here also the river 

 valley of the Souris, which is the largi-st stream in proximity to 

 the line, u.. ''-rgoes a remarkable change, its banks become 

 scarped and bare, and are seen to ba composed of stratified 

 fi mds, clays and sandstones belonging to the Lignite formation. 

 The beds here represented are probably among the lowest of the 

 Lignite group, and near their b ise is a remarkable nodularly 

 hardened s indstone, which has been formed by the action of the 

 ■weather wliere it outcrops in the valley into a group of extremely 

 pietnres((ue ;ind castellated rocks, known collectively by the 

 lialf-brecds as the Rovhe Ptrde. The lower part of this sand- 

 stone is grey, and so soft tliat it may be cut and scraped away 

 ■with a knife. The upper part is divided into thinner beds and 

 is hardened by calcareous cement. IJoth L.yers show false bedded 

 structure in great perfection, and the lower has been pierced by 

 ■window-like openings, due to weathering along lines of jointage. 



These rocks have bc'cn probably from time immemorial objects 

 of superstition to the Indians inhabiting this region of the plains, 

 and chiefly belonging to the Cree and Assinel)oin tribes. They 

 have covered the lower soft part of the sandstone with rude 

 carvings, some re|)resenting human figures on foot or on horse- 

 l> ick, others various animals of tiie chase, and many merely re- 

 sembling strings and necklaces of beads. These sandstones closely 

 resemble those described in Wyomi g and elsewhere to the south 

 at the base of the Lignite tertiary, and which there weather inco 

 similar fantastic forms, to which names such as "Fairy's Caves," 

 "' Hermit's Caves." (!te., have been applied. 



For iibout 15 miles westward along the Souris Valley, many 

 loiinks showing good exposures of the Lignite Tertiary rocks 

 occur. The strata there represented probably overlie those of 

 the Roche Percee, and cont:iin many beds of lignite, which those 

 seen immediately underlying the sandstone do not. 



The beds in association with which the lignites occur are 

 mostly arenaceous clays, sometimes changing into moderately 

 coarse sands or soft sandstones, but generally more resembling a 

 true clay of a hard character, and frequently passing intc a species 

 of clay-slmle. The colours of the beds are very varied, much 



