CONTENTS 



PAGE 



INTRODUCTION. By C. K. Swaetz, Charles Schuchert, and Charles S. 



Peosser 23 



General Relations of the Devonian 23 



Paleogeogeaphy of the Devonian 33 



Historical Review and Biiiliogeaphy 42 



THE LOWER DEVONIAN DEPOSITS OP MARYLAND. By Charles 



ScHucHEET, C. K. Swaetz, T. Poole Maynaed, and R. B. Rowe 07 



Introductory GO 



Stbatigkaphic and Paleontologic Chaeacteristics 84 



helderbeeg formation 84 



Introductory 84 



Subdivisions 84 



The Keyser Member 85 



Character and Thickness 85 



Fauna 85 



Keyser-Tonoloway Boundary 85 



The Coeymans Member 86 



Character and Thickness 80 



Fauna , 86 



Coeymans-Keyser Boundary 86 



The New Scotland Member 87 



Character and Thickness 87 



Fauna 88 



New Scotland-Coeymans Boundary 88 



The Becraft Member 88 



Character and Thickness 88 



Fauna 88 



Becraft-New Scotland Boundary 89 



Composite Section of the Helderberg Formation 89 



oriskany formation 90 



Introductory 90 



Subdivisions 91 



Shriver Chert Member 91 



Character and Thickness 91 



Fauna 92 



Ridgely Sandstone Member 92 



Character and Thickness 92 



Fauna 93 



Shriver-Ridgely Boundary 94 



Limits of the Oriskany 94 



Oriskany-Helderberg Boundary 94 



Romney-Oriskany Boundary 05 



Composite Section of the Oriskany 95 



