Obituary. 451 



The Academy of Natural Sciences nobly maintains its prominence 

 among the publishing Societies of the United States, surpassing them all 

 in the beauty of its quarto Journal and of the numerous plates with which 

 Its articles on natural history are illustrated. We are particularly struck 

 with the dravvings (on stone by Ibbotson from Gabb's originals) illustrat- 

 ing the fossil Polyzoa, which for perfectness have not been surpassed. 



We are reminded by the appearance of Mr. Lea's paper in this Part of 



— 4. Observations on the genus Unio, etc.; by Isaac Lea, LL.D., &c., 

 with 18 Plates, Vol. VIII, Part II, Feb., 1862, read Nov. 12, 1861, pp. 57- 

 115. Mr. Lea's papers on the Unionidae and other fiesh water genera are 

 too well known by all students of malacology to require any extended 

 notice at our hands. As far back as March, 1860, Mr. Lea stated {Proc. 

 Phil. Acad., March 13, 1860) that the number of species described or 

 known to exist in this department was as follows: Unio 465, Margari- 

 tana 26, Anodouta 59 = 550, to wliich he added as not yet described 



Ilonduras, Central America, and one in Canada— Unio 2\), Anodonta 

 8 = 37, making the grand total at that date 617. Since then he has 



Death of General 0. M. Mitchel.— Science mourns the sudden dea 

 by yellow fever, of the patriot-soldier and eminent sf.ientist, Major Gene 

 OttMSBr McKnight MiTCHEL, which occurred at Beaufort, S. C, on t 

 30th of October. 



He had just entered, with his accustomed zeal and energy, upon the ; 

 duous duties of this difficult Military Department, when befell asacrifi 

 to that fearful scourge, the general absence of which among our armi 

 on the southern coast has been among the most noticeable hygienic fa< 

 of the campaign. 



General (Prof.) Mitchel was born on the 28th of August, 1810, 



adolescence. He graduated as a cadet at West Point Military Acadeir 

 Mathematics. Ho subsequently studied and pra " 



and in 1834 accepted a chair of nial 

 cinuciti College, which he held until 

 of the Railway system of Ohio, by c 

 ant lines of Railway in that State. 



"The Cincinnati Observatory owes 

 O.M. Mitchel. In the years 1841 a 

 called 



: in the Cin 



He aide* 



irs were subscribed in shares of twenty-live dollars; ana 

 observatory was given by Nicholas Longworth, Esq. It c 

 acres of ground, on one^of the higlie- ^-^'^ - »'- "-^^ 



:. JotJB. Sci.— Secosd 6 



