91 



in its three stages of existence. By Joseph Leidy, M.D. Ex- 

 tracted from the Journal of the American Academy of Arts and 

 Sciences. Boston and Cambridge, 1848. 4to. — From the Au- 

 thors. 



Journal of the Franklin Institute. Third Series. Vol. XVII. No. 6. 

 June, 1849. Philadelphia. 8vo. — From the Institute. 



The Medical News and Library. Vol. VII. No. 78, and Supplement. 

 June, 1849. Philadelphia. 8vo. — From Lea and Blanchard. 



The African Repository and Colonial Journal. Vol. XXV. No. 6. 

 June, 1S49. Washington. 8vo. — From the American Coloni- 

 zation Society. 



A Narrative of Events which occurred in Baltimore Town during 

 the Revolutionary War: to which are appended various Docu- 

 ments and Letters, the greater part of which have never been 

 heretofore published. By Robert Purviance. Baltimore, 1849. 

 8vo. — From the Maryland Historical Society. 



Fac-simile Reprint of " Poor Richard's Almanac, for the year of 

 Christ, 1733. Printed and sold by B. Franklin, at the New 

 Printing Office, near the Market." Philadelphia, 1849. 12mo. 

 From E. D. Ingraham, Esq. 



Mr. Isaac Lea made the following communication upon 

 some reptilian foot-marks recently discovered by him in the 

 gorge of the Sharp Mountain, near Pottsville, Pa. 



It has not been until within a very few years that fossil " foot- 

 marks" have been discovered and sufficiently observed to identify 

 them with existing families and genera. Dr. Deane and Professor 

 Hitchcock observed many in the new red sandstone of Connecticut 

 and Massachusetts, and have described them in various papers in the 

 American Journal of Science and Arts. Recently the latter gentle- 

 man has published an extensive and able paper on the subject in the 

 Transactions of the American Academy of Arts and Sciences, Vol. III. 



Accompanying the " foot-marks," the surface of the layers was 

 frequently covered with " ripple marks, and the pits of rain drops." 

 Mr. Redfield also observed them in New Jersey. As strict science 

 is always disposed to receive new facts with caution, there was a 

 good deal of scepticism displayed on the announcement of these dis- 

 coveries; but the accumulation of evidence from various parts of the 

 world soon satisfied the doubts of the most scrupulous. It would 

 now be almost ridiculous to doubt " fossil foot-marks." There is no 

 geological fact better established. 



