OBSERVATIONS 



GENUS UNIO, 



TriOETIIER WITH 



DESCRIPTIONS OF NEW SPECIES, THEIR SOFT PARTS, AiND EMBRYONIC FORMS, IN 

 THE FAMILY UNIONIDiF], 



HEAD BEFORE THE ACADEMY OF XATrUAL SCIENCES OF PHILADELPHIA AND 

 PfBLISIIEn IN THEll! JOrRNAL. 



ISAAC- LEA, LL ])., 



PRESIDENT OF TllK ACADEMY OF XATLRAL SCIENCES OF PHU-ABELPHIA, ETC. 



WITH THIRTY-FOUR PLATES. 

 VOL. 8. 



PHILADELPHIA: 

 PRINTED FOR THE AUTHOR. 



