BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 



Vol. 21, pp. 677-716 December 23, 1910 



PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY 



ORDOVICIC-SILrEIC SECTION OF THE MIA^GAN AND ANTI- 

 COSTI ISLANDS, GULF OF SAINT LAAVEENCE^ 



EY CHARLES SCIIUCHERT AND W. H. TWEXHOFEL 



{Presented before the Paleontological Society December 30, 1909) 



CONTENTS 



Page 



Introduction 678 



General statement of the geologic sequence 081 



Geologic section of Anticosti Island 684 



The long ranging species 683 



Mingah Islands succession 686 



Canadie system. Beekmantown series 686 



Romaine formation — thickness and general characteristics 686 



Romaine formation, Division A 686 



Romaine formation, Division B 687 



Romaine formation, Division C 687 



Correlations 688 



Ordovicic system. Chazian and Mohawkian series 688 



Mingan formation — ^thickness and general characteristics 688 



Mingan formation, Zone Ai 689 



Mingan formation. Zone A2 . . • 689 



Mingan formation. Zone A3 690 



Mingan formation. Zone A4 691 



Mingan formation, Zone A5 691 



Correlations 692 



Anticosti Island succession 693 



Ordovicic system. Macastey black shale 693 



Location and characteristics 693 



Correlation 694 



Cincinnatic system. Richmondian series 694 



General discussion of the series 694 



English Head formation (Richardson's Division A) 695 



Correlation 696 



Charleton formation (Richardson's Division B) 697 



Correlation 699 



Cincinnatic system. Gamachian series 700 



General discussion of the series 700 



Ellis Bay formation (Lower half of Richardson's Division C) 701 



Correlations 704 



1 Manuscript received by the Secretary of the Geological Society July 15, 1910. 

 XLVII— Bull. Geol. See. Am., Vol. 21, 1909 (677) 



