, OBSERVATIONS 
ON THE 
eee Ss NE OY 
TOGETHER WITH 
DESCRIPTIONS OF NEW SPECIES IN THE FAMILIES UNIONID/, COLIMACEA 
AND MELANIANA. 
READ BEFORE THE AMERICAN PHILOSOPHICAL SOCIETY, AND ORIGINALLY 
PUBLISHED IN ITS TRANSACTIONS. 
BY 
ISAAC LEA, 
MEMBER OF THE AM. PHIL. SOC.; OF THE ACAD. OF NAT. SCIENCES OF PHILADA.: 
OF THE ZOOL. SOC. OF LONDON; OF THE IMPERIAL 
Soc. OF MOSCOW, &C. &C. 
WITH NUME 
US PLATES. 
l¢ ig, 
PHILADELPHIA: 
PRINTED FOR THE AUTHOR. 
