(30 INTRODUCTION. 
tion of the wrong he was doing, and his practice was 
in this particular very loose. M. Deshayes, in the 
Encyclopedic, seems to have been careless in looking 
up his authorities, and had not awakened to the impor- 
tance of reforming the nomenclature by restoring origi- 
nal names, for winch he has since proved himself to be 
an able and zealous advocate. But it may be said, 
without justly incurring reproach, that neither of them 
seems to have considered it to be necessary, to pro- 
vide himself with the means of making such references 
to American authors, as was proper and essential in 
order to render his own works more accurate, and to 
guard against injustice to others. Indeed, so late as 
1839. M. Deshayes, in his continuation of M. FeYus- 
sac's work, in giving the synonymy of Helix sej tern- 
volva ascribes the specific name to M. Ferussac, over- 
looking entirely the fact that Mr. Say had published 
the species four years in advance of M. Ferussac, as 
plainly appeared from the dates of the respective works 
to which M. Deshayes referred in his own description. 
It may be said, in excuse, that the writings of Ameri- 
can naturalists, scattered as they are through various 
periodical publications, are procured witli difficulty in 
Europe. This is probably true, to a considerable ex- 
tent, but it is no more true than that similar European 
publications can hardly be obtained here. They can 
be obtained by those who deem them sufficiently im- 
portant to warrant some trouble in procuring them; 
and the author who undertakes a general work, like 
