2 JO On the Geology of the Island of Montreal 



a pear encrinite, from a specimen from Montreal, found by 

 Mr. Lee, (37th infantry,) and from Lake Simcoe, found by 

 myself, I have since met with, in a more perfect form, at the 

 natural steps above the Falls of Montmorenci, near Quebec- 

 It most probably does not belong to this family at all ; but is 

 a multilocular shell, resembling the orthoceratite. I am not 

 now prepared to add further respecting it, than that it is 

 straight or curved cylindrical, large in what we may pro tem- 

 pore call the middle, and tapering gradually towards the ex- 

 tremities : which, by the by, have not been seen. Its septa 

 are straight, (not sinuous,) transverse ; and average six to 

 the inch. In ten individuals no siphuncle has been discovered. 

 My largest fragment is four inches long, by nearly two in 

 greatest breadth. 



The accidental minerals occurring in the limestone of 

 Montreal, are in very small quantity, and few in number. 

 They are confined to purple fluor, in plates, lining fissures, 

 and as small cubes superimposed : yellow blende, in imbedded 

 crystalline masses : and iron and copper pyrites, in druses and 

 as coatings. 



The alluvial ridge, which surrounds two thirds of this island, 

 and is so distinct on the southern and eastern aspects of the 

 hill, may be considered as an ancient embankment, in one of 

 those vast bodies of water which were left by the last deluge ; 

 and which in the lapse of ages have undergone repeated sub- 

 sidences, until they have assumed their present shapes and 

 number. From whatsoever source this bank may have deriv- 

 ed its materials, its course and form have been imparted to it 

 by waters flowing nearly in the same direction as the Ottawa 

 and St. Lawrence of the present day : but at an elevation 

 which would give them an infinitely greater extent than they 

 now possess. I have traced it for one hundred and sixty-five 

 miles up the former stream, when I met with a barrier of sterile 

 hills, through which it forces its way, leaving behind it the 

 vast and sometimes fertile deposits in which Lakes des Allii* 



