138 Canadian Record of Science. 



We all know how the Silurian in similar disturbed districts 

 was originally made to include the Cambrian, and the latter 

 the rocks since separated as Pebidian, and how Logan's 

 Huronian has been made to include great masses of rock 

 he would not have admitted as members of it. Such mis- 

 takes are inevitable, and shou d not invalidate good names. 



With reference to the proposal to substitute the term 

 " Levis " for Quebec, all the objections to the latter name 

 would apply to the former. Besides this, the rocks exposed 

 at Levis are known by all who have studied the geology of 

 the Lower St. Lawrence, to be only a part of the Quebec 

 Group. The latter name is also the more appropriate to a 

 series so eminently characteristic of a large portion of the 

 Province of Quebec, and so well exposed and easily studied 

 in the vicinity of that city. It is besides to be observed, that 

 the Quebec Group represents that development of the lower 

 member of the Cambro-Silurian or Ordovician system, which 

 is characteristic of all the Eastern part of Canada, and 

 which connects this best, both as to rocks and fossils, with 

 the development in Western Europe, as for instance, the 

 Arenig and Skiddaw groups of England. 



I may saj T here also, that this is entirely independent of 

 the questions which have been raised as to the relative 

 position of the Sillery sandstone and Levis shales. Ad- 

 mitting with Hunt and Ells, that the Sillery sandstone near 

 Quebec is older than the Levis, this Sillery is only one 

 group of sandstones out of several, which elsewhere underlie 

 and overlie the Levis, and the Levis itself is only one of at 

 least three (possibly four) bands of shale holding different 

 groups of fossils, which belong to the great Calciferous- 

 chazy formation of the Quebec group. This is established 

 by Lapworth's studies of the Graptolites, and I well know 

 the facts, from my own observations in the Lower St. 

 Lawrenee, where I have passed the summer vacations of 

 many years, and have occupied some of my leisure in 

 studying these puzzling deposits; mainly, however, as a 

 lesson in the intricacies of disturbed and originally irreg- 

 ular strata for the benefit of my students. 



