XX1V PREFACE TO THE SECOND EDITION. 
foreign naturalists seem to have felt the necessity of establish- 
ing divisions in those immense genera, in which such incon- 
gruous species were formerly heaped together ; their groups 
are now precise and well defined, their descriptions sufliciently 
detailed, their figures scrupulously exact even to the most 
minute characters, and very frequently of the greatest beauty. 
Scarcely any difficulty remains therefore in determining the 
identity of their species, and nothing hinders them from com- 
ing to an understanding with respect to the nomenclature. 
This, unfortunately, has been almost neglected ; the names of 
the same genera, the same species, are multiplied as often as 
they are spoken of; and should this discord continue, the same 
chaos will be produced that previously existed, though arising 
from a different cause. | 
I have used every effort to compare and approximate these 
redundancies, and forgetting even my own little interest of 
author, have often given names which seem to have been form- 
ed expressly to avoid being compelled to avow the borrowing 
of my divisions. But in order thoroughly to execute this un- 
dertaking, this pinax of the animal kingdom, which becomes 
daily more and more necessary, to examine its proofs, and to fix 
on the definite nomenclature that would be adopted, by basing 
it on sufficient figures and descriptions, requires more space 
than I can dispose of, and a time imperiously claimed by other 
works. It is in the ‘‘ History of Fishes,’’ which, assisted by 
M. Valenciennes, I have commenced publishing, that I intend 
to give an idea of what I think might be effected with respect 
to all parts of the science. This is a mere abridgement, a 
simple sketch—fortunate will I be if I succeed in rendering 
it correct in all its parts. 
Various descriptions of a similar kind have been published 
on some of the classes, and I have carefully studied them all, in 
order to perfect my own. The «‘ Mammalogie’’ of M. Desma- 
rest, that of M. Lesson, the ‘‘ Traité sur les Dents des Qua- 
drupedes” of M. Frederick Cuvier, the English translation of 
my first edition by Mr Griffith enriched by numerous additions 
~ chiefly by Hamilton Smith, the new edition of the ‘« Ma- 
