MAKYLANI) GF.Or.OGICAL SURVEY Si? 



I'loiii till' oriijiiiic rciiiaiiis cxaiuiiiril." ( 'uiirad rrnm the lirsl aitplicil 

 tlu' |iaK'(iiil()l<iLii( al cv i(li'iu-i' hi' had ai(Hiir(Ml to an iiil('r|ir«'(atinii oT the 

 strali^rapliy; and, although many of his conclusions wore crrDncous, the 

 knowlodac of tlu- geology of Ihc Coastal Plain was very materially ail- 

 vanccd by his work. In this lirst paper such well-known early Ter- 

 tiary forms as Tiirrifella moiioni, CncuUaea (jiijunlni. and Crassalellu 

 aJaeformis are figured and described, while the presence of VeneriniriUn 

 planicosta Lamarck is also noted. By the use of the data afforded by 

 these investigations the strata at Fort Washington, were correlated with 

 the London Clay of England. 



In 1832 Conrad began the publication (in parts) of an important 

 work entitled "Fossil shells of the Tertiary formations of North 

 America." This and its companion volume upon the " Middle Ter- 

 tiary,"" commenced some years later, must be regarded as the basis of all 

 later work upon American Tertiary paleontology. In the earlier puljli- 

 cation Conrad regarded the deposits in the vicinity of Fort Washington, 

 as "Middle Tertiary."" and correlated them with the London Clay ami 

 Calcaire grossier of Europe, and the Claiborne beds of Alabama. 



Before the completion of Conrad's first work above mentioned Lea 

 jDublished his "" Contributions to geology."" in which a large number of 

 Eocene fossils are described and the stratigraphy of the Tertiary of the 

 Atlantic Coastal Plain is discussed. In this work the term Eocene is 

 first applied to the American LoAver Tertiary deposits, although the 

 general position of the deposits had already been recognized by Conrad. 

 The latter, however, in 1834, in his " Observations on the Tertiary and 

 more recent formations of a portion of the Southern States."' employs 

 the term Eocene for the Fort Washington deposits, although he there 

 regards them as younger than the Claiborne beds, and even suggests 

 their Miocene age. 



During the same year Professor William B. Eogers made his first con- 

 tribution to the Eocene geology of Virginia, and although this article 

 contained little of real importance, it is of interest as being the first of 

 a series of important publications upon the geology of Virginia. 



Dr. S. Gr. Morton, whose inyestigations were chiefly confined to the 

 Cretaceous, aiyes in his " S}Tiopsis, etc.,"'" published at this time, a 



