26 PTIYSIOGRAPHY AND GEOLOGY OF THE COASTAL PLAIN PROVINCE. 



In a letter the author reports that the infusorial stratum has been traced entirely 

 across the state. In some places it rests upon the Eocene at other times upon Miocene. 

 He therefore concludes that it should be referred to a position within and near the 

 bottom of the Miocene, although he doubts whether the infusorial strata all occur at 

 exactly the same horizon. Many imperfectly carbonized vegetable remains which "seem 

 to be referable to creeping and cryptogamous plants" are reported to occur in great 

 abundance at some localities. 



TuoMEY, M. Notice of the Discovery of a new Locality of the "In- 

 fusorial Stratum." 



Aiiier. Jour. Sci., vol. xliv, pp. 339-341, 1843. 



The writer describes a deposit of the "infusorial stratum" within the city limits of 

 Petersburg, 30 feet in thickness, and containing the casts of Pectens, resting upon the 

 Eocene. The author definitely refers the infusorial stratum to the Miocene and correlates 

 it with the Richmond bed on the basis of the microscopic fossils. 



1844 



Bailey^ J. W. Account of some new Infusorial Forms Discovered in 

 the Fossil Infusoria from Petersburg, Va., and Piscataway, Md. 

 Amer, Jour. Sci., vol. xlvi, pp. 137-141, pi. iii, 1844. 

 Several new species are described and figured. 



Ehrenberg, C. G. Ueber zwei neue Lager von Gebirgsmessen aus 

 Infusorien als Meeres-Absatz in Xord iVmeiika uiul eiiH' Vergleiclmng 

 derselben mit den organischen Kreide-Gebilden in Europe und Afrika. 



Bericht k. p. akad. Wiss., Berlin, pp. 57-97, 1844. 



Review Amer. Jour. Sci., vol. xlviii, pp. 201-204, 1845, by J. W. Bailey. 



The author describes 112 species of diatoms in the infusorial earth of Richmond, and 

 67 from the deposit at Petersburg, of which 46 are common to the two localities. 



EoGERS, H. D. Address (on American Geology, and Present Condition 

 of Geological Eesearch in the United States). 



Amer. Jour. Sci., vol. xlvii, pp. 137-160, 247-278, 1844. 

 A brief review of the geology of Eastern Virginia is given. 



1845 



Bailey, J. ^Y. Notice of some New Localities of Infusoria, Fossil and 

 Eecent. 



Amer. Jour. Sci., vol. xlviii, pp. 321-343. pi. iv, 1845. 



Gives tables of all known species then described from Petersburg and Kichmciid. 



Conrad, T. A. Fossils of the (]\Iedial Tertiary or) Miocene Foriiuitioii 

 of the United States, No. 3. 



Pp. 57-80, pis. 30-45, Phila., 1845. Republished by W. H. Dall, Wasliin.^ 

 ton, 1893. 



