JTo. 10. 



M0N0GRAPHY 



OF THE 



FAMILY UNIONIDH, 



OR NAIADES OF LAMARCK, 



(FRESH WATER BIVALVE SHELLS,) 



NORTH AMERICA 



ILLUSTRATED BY FIGURES DRAWN ON STONE FROM NATURE. 



BY T. A. CONRAD, 



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

 THE GEOLOGICAL SOCIETY OF PENNSYLVANIA. 



PHILADELPHIA: 



J. DOBSON, 108 CHESNUT STREET. 



BOSTON: PERKINS & MARVIN.— PITTSB URGH: JOHN I. KAY & Co.- 



NEW YORK: HALL & VOORHIES, 118 NASSAU STREET.— L ONDON. 



O. RICH, No. 12, RED LION SQUARE.— PARIS: ARTHUS 



BERTRAND, FILS, RUE HAUTEFEUILLE No. 23.— 



HAMBURGH: PERTHES & BESSER, 



No. 22, AM JUNGFERNSTIEG. 



E. G. DORSEY, PRINTER. 



May 1838. 



