PREFACE TO THE FIRST EDITION. XXVil 
M. Sonnerat, at the Isle of France by M. Mathieu, in the Nile and Red 
Sea by M. Geoffroy, &c. I was thus enabled to verify most of the 
species of Bloch, Russel, and others, and to have prepared the skeletons 
and viscera of nearly all the subgenera, so that this portion of the work 
will, I presume, present to icthyologists much that is new. 
As to my division of this class, I confess its inconvenience, but I still 
think it more natural than any preceding one. When I some time ago 
published it, I put it forth for what it was worth; and if any one discovers 
a better principle of division, and as conformable to the organization, ] 
shall hasten to adopt it*. 
It is well known that all the works, on the general division of the 
Invertebrated animals, are mere modifications of what { proposed in 1795, 
in the earliest of my memoirs; and the time and care I have devoted to 
the anatomy of the Mollusca in general, and principally to the know- 
ledge of the naked Mollusca, are likewise well known. The determina- 
tion of this class, as well as of its divisions and subdivisions, rests on 
my observations; the magnificent work of M. Poli had alone anticipated 
me by descriptions and anatomical researches, useful to me it is true, but 
confined to bivalves and multivalves only. I have verified all the facts 
furnished to me by that skilful anatomist, and I have, I think, marked 
with greater accuracy the functions of some organs. I have also endea- 
voured to ascertain the animals to which the principal forms of shells 
belong, and to arrange the latter from that consideration; but as to the 
ulterior divisions of those shells whose animals resemble each other, I 
have examined them only so far as to enable me to describe those admitted 
by Messrs. de Lamarck and de Montfort; even the small number of 
genera or subgenera which are properly mine, are derived from observa- 
tions on the animals. In citing examples I have confined myself to a 
certain number of the species of Martini, Chemnitz, Lister, and Soldani, 
and that only because the volume in which M. de Lamarck is to treat this 
branch, not being yet published, I was compelled to fix the attention of 
the reader on specific objects. In the selection and determining of these 
species, however, I lay no claim to the same critical accuracy I have em- 
ployed for the Vertebrated animals and the naked Mollusca. 
The excellent observations of Messrs. Savigny, Lesueur, and Desmarest, 
on the compound Ascidia, approximate the latter family of the Mollusca 
to certain orders of Zoophytes—a curious relation, and an additional proof 
of the impracticability of arranging animals on one single line. 
The Annulata (the establishing of which order, although not the name, 
belongs de facto to me) have, I think, been extricated from the confusion 
* The Second Edition, however, as will be seen in the Second Volume of this 
Translation, contains a new arrangement of the class of Fishes, which, though pre- 
senting some deficiencies in precision, still possesses the advantage of not breaking 
in upon its natural families.—Ene. Ep. 
