iV PREFACE. 



before mc belonging to the Smithsonian Institution. In addition 

 to these I have had the opportunity of studying all the original 

 specimens of Mr. Say, Prof. Haldeman, Dr. Gould, Mr. Lea, the 

 Academy of Sciences of Philadelphia, the Museum of Compara- 

 tive Zoology at Cambridge. I have received also tj^pical speci- 

 mens from almost all those who have described species, and 

 corresponded so generally on the subject, that were I to specify 

 those to whom I am indebted for information, the list would con- 

 tain the name of nearly every living American conchologist. 



The descriptions of orders, families, genera, and subgenera are 

 principally copied from "The Genera of Recent Mollusca." 



The subject is brought down to January, 1864. 



All the original figures of shells and lingual dentition were 

 drawn by Mr. E. S. Morse, of Gorham, Maine. 



W. G. BINNEY. 



Burlington, N. J., August, 1865 



