I 



ADVERTISEMENT. 



The following list has been prepared by Dr. Theodore Gill, at 

 the request of the Smithsonian Institution, for the purpose of 

 facilitating the arrangement and classification of the Mollusks 

 and Shells of the National Museum ; and as frequent applica- 

 tions for such a list have been received by the Institution, it has 

 been thought advisable to publish it for more extended use. 



JOSEPH HENRY, 



Secretary S. I. 



Smithsonian Institution, 



Washington, January, 1871 



ACCEPTED FOR PUBLICATION, FEBRUARY 28, 1870. 



(iii ) 



