INTRODUCTION. 

Tur large number of figures in so small a space, and the 
circumstance that many of the shells there indicated have not 
been delineated, or even mentioned in more recent iconogra- 
phies, have rendered Wood’s Index Testaceologicus, a work 
of acknowledged utility and general popularity. Its value to 
the naturalist, has, however, been much diminished by the 
now obsolete method of the classification adopted, (that of 
Linnzeus) by the uncertainty or incorrectness of its recorded 
localities, and by the too frequently erroneous appellations 
(erroneous according to the present more restrieted notions of 
permitted variation) bestowed upon the objects engraved. 
These defects it has been the object of the present edition to 
amend. 
It is hoped that the Synopsis will remedy the inconvenience 
of seeking the species of a Lamarckian genus in plates adapted 
to the arrangement of Linneus, for by its aid, the concholo- 
gist can readily discover with what figures his specimens should 
be compared. Any change, indeed, in the relative position 
of the drawings to accord with the progressive advances of 
Lamarck, Sowerby, and Deshayes, would probably be futile, 
since the genera, throughout zoology, in the present tran- 
sitional stage of natural science, are continually being sub- 
divided and renamed; hence ¢heir systems likewise may 
prove as ill-adapted to the more stringent requirements of 
the coming generation, as that of their great predecessor to 
the enlarged ideas of the present era. 
The localities have been revised and augmented through 
the increased experience which the researches of Quoy and 
Gaimard, Cuming, Hinds, D’Orbigny, and other exploring 
a 

