28 r.OYAL SOCIETY OF CANADA 



lu 1878, Dr. Hunt, in summing up the list of systems and forma- 

 tions in Canada or eastern North America, proposed the following 

 sclieme of nomenclature: 



Laurentian ; — Comprising a lower division, the Ottawa gneiss, and 

 an upper division, the Grenville series, between which is a supposed 

 Mant of conformity, the two constituting the lower Laurentian of Logan. 



Norian ; — The Labradorian or upper Laurentian of Logan. 



Huronian : — The Green j^Iountain scries or altered Quebec Group 

 of Logan. 



Montalban ; — The White Mountain or mica schist series. 



Taconian ; — The lower Taconian of Emmons or the Hastings series, 



Keweenian ; — The Copper-bearing series of Lake Superior. 



Cambrian ; — Among other things including the Quebec Group of 

 Logan. 



Siluro-Cambrian. 



Of the names here indicated it may be remarked that the Montal- 

 ban and Taconian have never been definitely or generally recognized in 

 discussions on Canadi:m geological problem?, while several of them ap- 

 parently relate to groups of rocks in the Huronian system which are 

 practically on the same horizon. 



In 1881 an important scheme of nomenclature was presented by Dr. 

 Selwyn, the late director of the Geological Survey, for use as a guide in 

 the colouring of the maps issued by that department. In this scheme the 

 upper member of the Palaeozoic formations was styled Permian or upper 

 Carboniferous, and a series extending from this to the base of the 

 Oriskany or lower member of the Devonian, was styled upper 

 Palœozoic. The lower Palœozoic began with the Lower Helderberg, or 

 upper member of the Silurian series, and extended downwards to the top 

 of the Huronian. This portion included, as sub-divisions, the 

 Silurian, Cambro-Silurian and the Cambrian, the latter of which was 

 supposed to include all beneath the Chazy formation. 



Ill this sclicme the Cambrian was made to comprise, as its upper 

 member apparently, the Sillery and Levis divisions of the Quebec group, 

 and the upper and lower Calciferous, supposed to re])resent the middle 

 portion of the system, while the upper and lower Potsdam, the latter in- 

 cluding the rocks of the St. John group or Acadian of Xew Brunswick, 

 were held to pertain to the lowest part, or to represent the lowest Cam- 

 brian. 



Since the date of this sclieme the formations in tlic Ottawa and St. 

 Lawrence basins have been studied very carefully and the views then 

 expressed have as a result been largely modified. 'J'hus it was found 

 that, in this area mentioned, the several formations from the top of the 



