\TIONS | 
a an 
TOGETHER WITH 
__ DESCRIPTIONS OF NEW SPECIES IN THE FAMILIES NAIADES, 
_ COLIMACEA, LYMNA ANA, MELANIANA 
- AND PERISTOMIANA. 
4 
WITH NUMEROUS PLATES. 
iat ISAAC LEA, 
MEMBER OF THE AMERICAN PHILOSOPHICAL SOCIETY, 
: no ETC, Bic.) 
~y 
VOL. NX 
PHILADELPHIA: 
PRINTED FOR THE AUTHOR. 
