PREFACE. 
Anticipating that the publication of the Plates 
forming the third volume of my late father’s work 
on the ‘‘ Terrestrial Mollusks and Shells of the 
United States,” will excite increased attention to 
that subject, it has been suggested to me by my 
friend, Mr. Thomas Bland of New York, that a re- 
print of the original descriptions and accompanying 
remarks of Thomas Say will materially assist in the 
study of this branch of Zoology. 
I have accordingly collected and now publish, 
from the scattered and generally inaccessible writ- 
ings of Mr. Say, all that relates to our terrestrial 
species. 
These pages are offered to the Conchologists of 
America and Europe to aid and encourage them in 
their investigations, and to induce a just apprecia- 
tion of the labors of our first and greatest Naturalist. 
W. G. BINNEY. 
Germantow'^ Philadelphia^ 
