40 THE PHYSICAL FEATURES OF CALVERT COUNTY 



1818. 



Maclure, Wm. Observations on the Geolog}' of the United States 

 of America, with some remarks on the probable effect that may be pro- 

 duced by the decomposition of the different classes of Eocks on the the 

 nature and fertility of Soils. Two plates. 



Republished in Trans. Amer. Phil. Soc, vol. i, n. s., 1818, pp. 1-91. 

 Leon. Zeit., i, 1826, pp. 124-138. 



1830. 



Hayden, H. H. Geological Essays; or an Inquiry into some of the 

 Geological Phenomena to be found in various parts of America and 

 elsewhere. 8vo. pp. 412. Baltimore, 1830. 



1834. 



Finch, John. Geological Essay on the Tertiary Formations in 

 America. (Eead Acad. Nat. Sci., Phila., July 15, 1833.) 

 Amer. Jour. Sci., vol. vii, 1824, pp. 31-43. 



Say, Thomas. An Account of some of the Fossil Shells of Mary- 

 land. 



Jour. Acad. Nat. Sci., Phila., vol. iv, 1824, pp. 124-155. Plates 7-13. 



1835. 



Van Eensselaer, J. Lectures on Geology; being outlines of the 

 science, delivered in the New York Antheneum in the year 1835. Svo. 

 pp. 358. New York, 1835. 



1838. 



Vanuxem, L., and Morton, S. G. Geological Observations on Sec- 

 ondary, Tertiary, and Alluvial formations of the Atlantic coast of the 

 United States arranged from the notes of Lardner Vanuxem. (Eead 

 Jan. 1828.) 



Jour. Acad. Nat. Sci., Phila.. vol. vi, 1829, pp. 59-71. 



1830. 



Conrad, T. A. On the Geology and Organic Eemains of a part of the 

 Peninsula of Maryland. 



Jour. Acad. Nat. Sci., Phila.. vol. vi, pt. 2, 1830, pp. 205-230, with two plates. 



