C N T E N T S 



Descriptions of New Genera and Species of the Family Unionidse. Read Dec. 29th, 1857, ■ Page 9 



" New Embryonic Forms of Thirty-eight Species of Unionida;. Read Nov. 23d, IS.'JS, 43 



'< New Unionida of the United States. Read Nov. 23d, 1858, .... ^1 



