Maryland Geological Survey 37 



pointed out the fact that Morton's uppermost division of the Cretaceous 

 was really of Eocene age. 



Philip T. Tyson in 1860, in his first report as State Agricultural 

 Chemist, referred to the Cretaceous fossiliferous greensand of the Eastern 

 Shore of Maryland and also mentioned the occurrence of the same forma- 

 tion to the south of Baltimore, although the latter observation was not 

 substantiated by authentic paleontological data. He, furthermore, recog- 

 nized the presence of some of the New Jersey Cretaceous divisions upon 

 the Eastern Shore of Maryland but made little or no attempt at their 

 delimitation. 



For many years sugsequent to Tyson's work nothing of importance was 

 accomplished in the interpretation of the Cretaceous deposits of Mary- 

 land. In 1889, however, the writer described the presence of fossiliferous 

 Upper Cretaceous beds in Anne Arundel and Prince George's counties, 

 Maryland, a number of highly fossiliferous localities being found at 

 various points throughout this area. Many well-known Cretaceous fossils 

 already described from the Xew Jersey formations were recognized and 

 listed in this publication. 



Subsequent to the publication of this article further investigations 

 were carried on by the writer and his associates on the Cretaceous deposits 

 of the state. At the same time a number of other students were engaged 

 in a study of this and adjacent areas, among them P. E. TJhler and X. H. 

 Darton, who proposed names for several of the formational units, Uhler 

 proposing the names Baltimorean and Albirupean, the former represent- 

 ing the Potomac deposits described in the Maryland Geological Survey 

 report on the Lower Cretaceous and the Albirupean portions of the non- 

 marine strata younger than the Potomac that are discussed in the present 

 report. Darton proposed the name Magothy formation for the deposits 

 overlying the Earitan, and the name Severn for the still later Cretaceous 

 deposits of the state which the author of this chapter has correlated 

 with the Matawan and Monmouth formations established in Xew Jersey 

 and which contain quite distinctive faunas. 



The relations of the Cretaceous deposits throughout the northern half 

 of the Atlantic Coastal Plain, including Maryland, Delaware, and Xew 



