PREFACE 



The present volume is the sixth of a series of reports dealing with 

 the systematic geology and paleontology of Maryland, the Devonian, 

 Lower Cretaceous, Eocene, Miocene, and Plio-Pleistocene deposits having 

 already been fully described. 



The Upper Cretaceous deposits which form the subject-matter of the 

 present volume are extensively developed in the Maryland area, and the 

 Maryland section is the type for the Middle Atlantic Coastal Plain. Simi- 

 larly the faunas and floras of the Upper Cretaceous are fully represented. 



The Upper Cretaceous deposits are described by Professor Win. Bullock 

 Clark, of the Johns Hopkins University, who has devoted many years to a 

 study of the Cretaceous of the Atlantic Coastal Plain. The chapter on 

 Petrography and Genesis of the Sediments is contributed by Dr. Marcus 

 I. Goldman, a former student of the Johns Hopkins University. 



The paleontological investigations have been jointly conducted by 

 several experts. The Vertebrata, and the fossil plants, which are espe- 

 cially prominent in the Magothy formation, have been described by 

 Professor Edward W. Berry, of the Johns Hopkins University, who has 

 also contributed the chapter on the Upper Cretaceous Floras of the World. 

 The abundant molluscan faunas of the Matawan and Monmouth forma- 

 tions have been described by Dr. Julia A. Gardner, of the Johns Hopkins 

 University. The Arthropoda have been described by Dr. Henry A. 

 Pilsbry, of the Philadelphia Academy of Natural Sciences ; the Bryozoa 

 by Dr. R. S. Bassler, of the U. S. National Museum ; the Echinodermata 

 by Professor Wm. Bullock Clark; and the Anthozoa by Dr. L. W. 

 Stephenson, of the U. S. Geological Survey. 



Grateful acknowledgment is made to all who have assisted in the 

 present study ; especially to Mr. A. B. Bibbins of Baltimore for much 

 information regarding the stratigraphy of the Raritan and Magothy 

 formations, and to Dr. T. W. Stanton and Dr. L. W. Stephenson for 



