PREFACE BY THE EDITOR. 



Much of the coufusion which already exists in the synoaoiny of 

 American MoUusca, has arisen from the general inaccessibility of 

 the writings of Thomas Say. Scattered through numerous and 

 costly works and obscure publications, they have always been ob- 

 tained with difficulty, and for many years past a large portion of 

 them have become absolutely unattainable. His species have been 

 known to most American conchologists rather by tradition than 

 from a careful study of his excellent descriptions ; a fact readily 

 accounting for the confusion which is to be found in the more 

 recent American and European works. 



To remedy this evil in the department in which my personal study 

 has been more particularly devoted, I collected and published, in 

 1856, all Mr. Say's descriptions of land shells. Having since thee 

 been requested to add the fluviatile and marine species, I have now 

 undertaken to do so, hoping thereby to induce a just appreciation 

 of the labors of our greatest Naturalist, as well as to increase the 

 facilities of the student of American Conchology. 



This volume contains all the writings of Mr. Say on recent Con- 

 chology, excepting his " Glossary of Conchology," and " List of 

 Exotic Shells in my Cabinet." The extracts from the uunieroas 

 original works are given as nearly as possible in chronological order, 

 the descriptions of terrestrial species being placed collectively at 

 the commencement. To remedy the inconvenience of not having 

 the various genera and species more nearly collated, I have added 

 a complete alphabetical catalogue of all the species described in 

 Mr. Say's writings, with a reference to the date, volume, page, and 

 figure of the original publication and of this reprint. To this must, 

 be referred all questions relating to priority of publication of any 

 disputed species. 



The plates include all the figures ever published by Mr. Say. 

 Plates 1 to 68, inclusive, have been printed from the original copperb 

 of the " American Conchology." Plates 69, 70, 71, 72, are fac simi- 

 les of the plates of Nicholson's Encyclopedia. On plate 70 will 

 also be found fac similes of the figures of Modiola opifex, from the 

 Journal of the Academy. Plates 73 and 74 are printed from the 



