LHE -SURALIGRAPHY OF THE: POTOMAC GROUP IN 
MARYLAND." 
. CONTENTS. 
Introduction. 
Description of the deposits. 
The Patuxent formation. 
Name and areal distribution. 
Leading features of the deposits. 
Characteristic local sections. 
Fossils. 
The Arundel Formation. 
Name and areal distribution. 
Leading features of the deposits. 
Characteristic local sections. 
Fossils. 
The Patapsco formation. 
Name and areal distribution. 
Leading features of the deposits, 
Characteristic local sections. 
Fossils. 
The Raritan formation. 
Name and areal distribution. 
Leading features of the deposits. 
Characteristic local sections. 
Fossils. 
Interpretation of the deposits. 
Sedimentation and structural relations. 
Correlation. 
The Taxonomic views of other writers. 
Comparative Taxonomic table. 
INTRODUCTION. 
The recent controversy regarding the age of the Potomac 
formation, which has been precipitated as the result of the con- 
flicting evidence presented by the palaobotanists and the verte- 
brate paleontologists, suggests the necessity of determining the 
*The investigations have been carried on under the auspices of the Maryland 
Geological Survey and the Woman’s College of Baltimore. 
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