OBSERVATIONS 



GENUS UNIO 



TOOETHER WITH 



nESCRIPTIONS OF NEW SPECIES, THEIR SOFT PARTS, AND EMBRYONIC FORMS, IN 

 THE FAMILY PNIONIDiE, 



REAP BEFMRK THK ACADEMY OF NATURAL SCIENCES OF PHILADELPHIA AND 

 PUBLISHED IN THEIR JOURNAL. 



BY 



ISAAC LEA. LL. D., 



PRESIDENT OF THK ACADEMY (IF NATURAL SCIENCBS OF PHILADELPHIA, F,Tr. ETC. 



WITH TWENTY-FIVE PLATES 



VOL. 



r 11 I I, A l> E L P H I A : 



PniNTED FOR THE AUTHOR. 



