XX TABLE OF CONTENTS. 



The graptolites of Point Levis ........ 399 



Discover)' of trilobites at Point Levis 400 



Logan describes and defines the Quebec group 401 



He supposes a great and continuous dislocation ..... 402 



Hall accepts Logan's stratigraphical conclusions 403 



Potsdam of the Ottawa basiu and of Wisconsin . . . . . 403 



Its relations to the primordial of Europe . ..... 404 



History of the Paradoxides Harlani of Braintree 405 



The primordial fauna in Newfoundland and New Brunswick . . 406 



Murray on the geology of Newfoundland 406 



The Lower Potsdam fauna of Billings 407 



Fossiliferous rocks of Troy, New York 407 



Menevian fauna in New Brunswick 407 



Crystalline schists of Nova Scotia 408 



Eophyton and its supposed geological relations 409 



Hicks and Barrande on the early trilobitic fauna 409 



Murray on ancient fossiliferous rocks in Newfoundland . . . 410 



Dawson on ancient foraminiferal forms 411 



On the Palaeotrochis of Emmons 411 



Billings on paleontological breaks in the Ottawa basin . . . .412 



The true horizon of the Levis limestone 412 



Its equivalents in Great Britain and elsewhere 412 



Unconformability of Calciferous and Trenton formations . . . 413 



Discordance between the Quebec and Trenton groups .... 413 



Lesley on a similar discordance in Pennsylvania ..... 414 



The Chazy formation on the Ottawa River 414 



Absence of the second fauna to the eastward 415 



Distribution of the Lower Helderberg fauua 415 



History of the Oneida conglomerate 416 



Mingling of second and third faunas on the Saguenay .... 417 



Fossiliferous rocks of Anticosti 417 



Middle Silurian division in Great Britain 417 



Middle Silurian of Billings different therefrom 418 



Two faunas in the Upper Silurian of Murchison 418 



The Onondaga and Water-lime formations 418 



Introduction of the terms Silurian and Devonian in America . . . 419 



Views of De Verneuil and of Hall 419 



Names adopted by the geological survey of Canada 420 



The geological survey of Pennsylvania 420 



The nomenclature adopted by Rogers 421 



Rogers on the British equivalents of American rocks .... 422 



Errors of the Silurian nomenclature 422 



The Upper Cambrian or Siluro-Cambrian division .... 423 



Jukes and Giekie on the Silurian nomenclature 424 



Barrande's downward extension of Silurian 424 



Great importance of Sedgwick' s geological labors 425 



