3 "Tt i 



C~JG 



MONOGRAPH! 



OF THE 



FAMILY UNIONID^E, 



OR NAIADES OF LAMARCK, 



(FRESH WATER BIVALVE SHELLS,) 



OF 



NORTH AMERICA, 



ILLUSTRATED BY FIGURES DRAWN ON STONE FROM NATURE. 



BY T. A. CONRAD, 



CURATOR OF THE ACADEMY OF NATURAL SCIENCES OF PHILADELPHIA, HONORARY MEMBER OF 

 THE GEOLOGICAL SOCIETY OF PENNSYLVANIA. 



PHILADELPHIA: 



J. DOBSON, 108 CHESNUT STREET. 



1836. 



