THE FIVE DIVISIONS OP THE "QUEBEC GROUP." 467 



5. The Quebec Citadel series, also Cambro-Silurian, the horizon of which 

 is not yet definitely fixed, though the fossils from it have a distinctly Tren- 

 ton-Utica aspect and may represent a thickening of the lower portion of the 

 latter formation. These rocks are also seen on the island of Orleans at its 

 northwest extremity and for several miles eastward, as well as at various 

 points on the St. Lawrence. They are separated from divisions three and 

 four by well defined lines of fault. 



These are succeeded upward by the fossiliferous Utica and Hudson River 

 or Lorraine shales, which are seen at Montmorency falls, Beauport, and 

 other places in the vicinity of Quebec. 



