SYNOPSIS 



THE FAMILY OF UNIONIDiE. 



Some students of the Molliisca have treated the Family Umomdce as of little 

 importance or interest. This has evidently ai'isen from the fact that they are com- 

 mon and generally not attractive to the eye as the marine species are. But when 

 we consider that over 1000 hooks and papers are inserted in the list herein presented, 

 we must acknowledge that most of the hest writers on Malacology have given space 

 and attention to the importance of the subject. Deshayes very properly remarks : 

 "Aussi il est peu de genres dans le grand ensemble des Mollusques qui ait ete plus 

 frequemment mentionne que celui-ci."' 



And Swainson in his Malacology very properly remarks that "The UnionidcB, of 

 all the groups of Dithteia (^Concliifera), is that which contains the greatest modifi- 

 cations of form; insomuch that it becomes almost impossible, in some of its minor 

 divisions, to determine which are species and which varieties," &c. — P. 290. 



The following table of arrangement and synonymy was undertaken purely with 

 the view, and in the hope of clearing away the difficulties which had encumbered 

 one of the most interesting families of the MoUusca. In this attempt I met, while 

 pursuing the task, with obstructions and difiiculties which I little anticipated at its 

 commencement. The want of some of the books of reference, and the confusion 

 which reigned throughout many of them, sometimes presented obstacles which seemed 

 almost insurmountable. The extensive and admirable library of the Academy of 

 JS^atural Sciences of Philadelphia has greatly aided me in this and the previous 

 editions. In attempting to establish the synonymy, I have endeavored to render the 

 strictest justice, and if, in any case, it be found that I have failed to do this, it will 

 be a matter of sincere regret. All corrections will be gratefully acknowledged. 



^ Traite Elementaii-e, T. xi. p. 195. 



