88 



The Magazine of Natural History. New Series. Edited by Edward 



Charlesworth. Vol. II., No. 25. London, 1839. — From the 



Editor. 

 Communication relative to the West Branch and Alleghany Canal. 



By B. Aycrigg. Harrisburg, 1839. — From the Author. 

 The American Medical Library and Intelligencer. By Robley 



Dunglison, M. D. Vol. II. No. 24, and Vol. III., No. 1. 



Philadelphia, 1839. — From the Editor. 

 The Augustan Age. A Lecture before the Athenian Institute. By 



Charles D. Meigs, M. D. Philadelphia, 1839.— From the 



Author. 

 Statistical Tables, exhibiting the Condition and Products of certain 



branches of Industry in Massachusetts, for the year ending April 



1, 1837. By John P. Bigelow. Boston, 1838 From Mr. 



Elliot Cresson. 

 Real Museo Borbonico. Nos. 37 to 47. Naples, 1833 to 1836.— 



From the King of the Two Sicilies. 

 Vocabolario Universale della Lingua Italiana. Nos. 31 to 35. 



Naples, 1837 and 1838.— From the Chevalier Morelli. 



The Committee to whom was referred a paper, entitled. 

 " Contributions to the Geology of the Tertiary Formations of 

 Virginia. Second Series. By Professor William B. Rogers, 

 and Professor Henry D. Rogers," reported in favour of the 

 publication of the Memoir, which was ordered accordingly. 



The object of this communication is to describe the Geology of the 

 Peninsula embraced between the Potomac and Rappahannock rivers, 

 extending from the Chesapeake Bay to the limit of tide water, near 

 Fredericksburg. 



This area consists almost exclusively of the two great divisions of 

 the Tertiary Deposites of Virginia, namely, the Eocene and Miocene 

 formations. 



The paper commences with a sketch of the topographical features 

 of the peninsula, making allusion, among other points, to the interest- 

 ing terraced configuration of the land bordering the valleys of the 

 two rivers. It then proceeds to delineate the boundaiies of the 

 Eocene and Miocene formations. The Eocene is shown to occupy 

 the western part of the peninsula, overlapping at its western edge the 

 secondary sandstone of Fredericksburg, and extending eastward 

 with a very gentle eastern dip beneath the overlying Miocene deposites, 



