44 
Mr. Toalmin Smith on the Classification 
even detected, necessarily stains the matrix beyond the structure 
itself ; and it requires the nicest and most painful discrimination 
to determine what is due to structure and what to mere iron 
stain. Feeling however that such a course of investigation could 
furnish the only true materials of a natural classification, I have 
endeavoured to overcome these difficulties. And it may save the 
task both of making and answering many objections if I now 
state that I have, with this object, dissected with elaborate care 
numberless specimens, in addition to many hundreds of sections 
of specimens both in flint and chalk, which, with the like purpose, 
I have made. There is not one species which I have established 
which I have not determined from actual and personal section 
of specimens either in chalk or flint, usually both, and in which, 
with scarcely an exception, 1 have not followed and traced out 
the actual fold with the knife and needle. 
My aim has been to present such a classification and no- 
menclature as should be intelligible and at the same time ex- 
pressive; which, whether respect be had to genus, section, or 
species, should give some accurate and specific idea of the point 
on which the respective division has been founded; that thus a 
mere inspection of the table of classification may carry with it 
some real and true ideas as to the objects included*. The name 
descriptions so long before the world, and so often repeated, are funda- 
mentally erroneous, — the conclusions as to the oeconomy of the animal being 
necessarily, therefore, as fundamentally erroneous. It is upon the same 
laborious care which has enabled me to demonstrate these facts, that I rely 
in attempting the descriptions now to be given of the dilferent modes of 
folding assumed by that membrane, and the superficial appearances of 
which have misled these observers. 
* It is usually unadvisable to alter names once applied ; but where the 
character of an object has been wholly misunderstood, not even its generic 
or structural character having been known (see the last note), there can 
be no claim to retain old names. Their retention is then generally mis- 
chievous as a mere perj)etuation of error. I fully agree with Dr. Farre {ut 
ante, p. 405, note) that oftentimes confusion and doubt (in nomenclature) 
can only be dispelled by beginning de novo,” and so appl^nng new names 
in harmony with a system founded in nature and upon some definite prin- 
ciple. I think it better to give here all the names which occur in Mr. 
Morris’s Catalogue whose objects appear to belong to the Ventriculidae, — 
a list which will, moreover, show the "confusion and doubt” which have 
hitherto prevailed in the nomenclature of this family. 
Names in Morris’s Catalogue. 
Choanites flexuosus 
Choanites subrotundus 
Ventriculites alcyonides [OcellariaJ 
alternans 
Bennettise 
In the following classification. 
Ventriculites latiplicatus. 
Cephalites constrictus. 
Ventriculites quincuncialis. 
Probably V. bicomplicatus. 
One of the Cephalites annulati, but 
no accurate description ; and the 
figures of Michelin and Mantel 1 
totally differ. 
