24 THE EOCEN"E DEPOSITS OF MARYLAND 



the interpretation of the strata is thus made accessible. The present 

 report inchides the results of such an exhaustive study of the fauna of 

 the Eocene of Maryland, together with a critical review of the species 

 described by previous authors, as well as the description of a large num- 

 ber of new forms. It is believed that a much more accurate idea of the 

 faunal characteristics, as well as of the physical conditions prevailing 

 during the Eocene period on the Middle Atlantic Coast, will result from 

 the methods pursued in this investigation. Certainly the data for the 

 comparison of the fauna with those of other areas will be greatly aug- 

 mented. 



HiSTOEICAL EeVIE-W." 



On account of its extensive waterways and the ready access thereby 

 gained, the Atlantic Coastal Plain was early visited for purposes of geo- 

 logical investigation. At first the observations were of the most general 

 character, no attempt being made to differentiate the deposits or even 

 to correlate the strata as a whole with those of other districts. 



Among the earliest investigators of the region was Professor Peter 

 Kalm, who was sent out in 1749 under the auspices of the Swedish Eoyal 

 Academy of Sciences to make a study of the various branches of natural 

 history in America, and who spent considerable time in a study of the 

 northern Coastal Plain. 



He was followed in 1777 by Dr. Johann David Schopf, of Germany, 

 who visited America in order to study the geological features of the 

 eastern portion of the continent. The importance of his observations, 

 which mark considerable advance over those of Kalm, has not been very 

 generally recognized by later Avriters, but he showed a remarkably keen 

 insight into the geology of eastern North America, Avhich was lacking 

 on the part of some of his successors. 



The first attempt to correlate the deposits of the eastern United State^j 

 with the geological cohinm then established in Europe was made by 

 William Maclure, in 1S09, in his Observations upon the Geology of the 



I lioth ill this and in tlic subsetiueut chapter, coiiiprisiufi- the Bibliography, refer- 

 ences are made to articles and books dealinj^ also with the Eocene of Delaware and 

 V'irtriiiia since the deposits are embraced in the same geologic province with those of 

 Marvl.'iiid. 



