I. 



CONTENTS. 



No. IV. 



Description of Six New Species of the Genus Unio ; embracing the 

 Anatomy of the Oveduct of one of them, together with some Anato- 

 tomical Observations on the Genus. By Isaac Lea. 259 



No. V. 

 On the Geographical Distribution of Plants. By C. Pickering, M.D. 274 



No. VI. 



An Account of some Human Bones found on the Coast of Brazil, near 



Santas. By C. D. Meigs, M.D. - - - 285 



No. VII. 

 Some Observations on the Moulting of Birds. By George Ord. - 292 



No. VIII. 



Experiments made on the Poison of the Rattlesnake ; in which the 

 Powers of the Hieraceum Venosum, as a Specific, were tested ; 

 together with some Anatomical Observations on this Animal. By 

 R. Harlan, M.D. - - 300 



No. IX. 



On the motion of Solids on Surfaces, in the Two Hypotheses of Perfect 

 Sliding and Perfect Rolling, with a Particular Examination of their 

 small Oscillatory Motions. By Henry James Anderson, Professor of 

 Mathematics and Astronomy in Columbia College, New York. 315 



No. X. 



General Observations on the Birds of the Genus Tetrao ; with a Synop- 

 sis of the Species hitherto known. By Charles Lucien Bonaparte, 

 Prince of Musignano, &c. - - - 38: 



