xii INTRODUCTION. 
next in succession to that species it most nearly resem- 
bles and. approximates. 
The first column of the Catalogue which follows the 
description of the genus will, it is presumed, be found 
to contain a comprehensive list of all the species at 
present described. In the second column is placed a 
list of the localities, which from our connections we 
have been able greatly to enrich and correct. The 
last column contains the trivial or common names. 
The plates which embellish this work are taken from 
specimens in our own cabinet, and we are indebted to 
the kindness and indefatigable exertions of an artist 
of the greatest talent, for the accurate and elegant de- 
lineation of them. 
