6 PREFACE. 



to the conchologists of the country for aiding 

 him in various ways, among whom may be 

 mentioned Mrs. Say, Messrs. Adams, Anthony, 

 Binney, Blanding, Conrad, Couper, Emerson, 

 Gould, Lea, LeConte, Lewis, Mighels, Nuttall, 

 Phillips, Poulson, Wagner, Wood, and Whit- 

 temore. 



