i.'^ iS^ 



OBSERVATIONS 



GENUS UNIO, 



TOGETHER WITH 



DESCRIPTIONS OF NEW GENERA AND SPECIES IN THE FAMILIES 



NAIADES, CONCHA, COLIMACEA, LYMNiEANA, ME- 



LANIANA AND PERISTOMIANA . 



CONSISTING OF 



FOUR MEMOIRS READ BEFORE THE AMERICAN PHILOSOPHICAL SOCIETY FROM 

 1827 TO 1834, AND ORIGINALLY PUBLISHED IN THEIR TRANSACTIONS. 



WITH COLOURED PLATES. 



BY 



ISAAC LEA, 



.MEMBER OF THE AMERICAN PHILOSOPHICAL SOCIETY ; 



OF THE ACADEMY OF NATURAL SCIENCES OF PHILADELPHIA ; 



OP THE LYCEUM OF NATURAL HISTORY OF NEW YORK ; 



OF THE GEOLOGICAL SOCIETY OF PENNSYLVANIA; 



HONOR.IRY MEMBER OF TUB MEDICAL SOCIETY OF ORANGE COUNTY, NEW YORK ; 



MEMBER OF THE ROYAL PHYSICAL SOCIETY OF EDINBURGH ; 



OP THE BRITISH ASSOCI.^TION OF SCIENCE ; 



OF THE NATURAL HISTORICAL SOCIETY OF MONTREAL ; 



CORRESPONDING MEMBER OF THE LINNJIAN SOCIETY OF BOURDEAUX ; 



ETC. ETC. 



PHILADELPHIA: 

 PRINTED FOR THE AUTHOR 



BY JAMES KAY, JUN. AND CO. 



