16 [Ffb., 1846. 



Unio crassus presented by him this evening, and stated that 

 it is one of those which he placed in the river Susquehanna? 

 in a living state, in the year 1841, a record of which fact will 

 be found at page 104, Vol. 1, of the Proceedings of the Aca- 

 demy. As no western species of Unio, except U. viridis, 

 Raf,, had hitherto been found in that river, Mr. Haldeman 

 had no doubt that the present specimen was in reality one of 

 those referred to. The growth had been inconsiderable, and 

 the genera] appearance very little changed. The other indi- 

 viduals of this and other species seem not to have survived. 



Stated Meeting, February 10, 1846. 

 Vice President Morton in the Chair. 



DONATIONS TO LIBRARY. 



Eleventh and Twelfth Memoirs with reference to the law of 

 Storms in India, &c. By Henry Piddington. Calcutta, 

 1845. From the Author. 



A letter was read from Mr. Piddington, dated Calcutta, 

 September 8, 1845, accompanying the donation of his Me- 

 moirs above announced, and calling the attention of the So- 

 ciety to the Postscript to the 11th Memoir, page 64, " where 

 a curious experiment will be found detailed, which sets the 

 whole question of circular or converging winds (winds blow- 

 ing towards a centre) completely at rest, for these seas at 

 least." 



A letter was read from Benjamin Silliman, Jr., dated New 

 Haven, February 6, 1846, requesting on behalf of M. Alcide 

 D'Orbigny, of Paris, exchanges between him and the Aca- 

 demy, both of books and specimens of Natural History, and 

 suggesting especially the transmission of the publications of 

 this Society for such of M. D'Orbigny 's works as may be de- 

 sirable for its Library. 



