species. They may not he new, or they may not be species at all,—but they
will be knoivn; and any mistake which has been committed will be at once
rectified,—any new name which has been wrongly imposed, immediately degraded
to a synonym.
Accordingly I have been careful in this respect; and I have in some instances,
given full descriptions, even of species which are certainly not new, but
which I did not find described by previous authors with all the detail that was
requisite for completely identifying them ; or, leaving out what they have noticed,
I have added such characters as they have omitted. My main object has been
to render all the species, whether rightly named or not, easily recognizable ; and,
however little the science may be advanced by what is brought forward, to make
that advance, so far as it goes, sure.
The method of description, and the mode of computing the fin-ray formula,
will be found conformable to the plan adopted in the “ Histoire des Poissons” of
Cuvier and Valenciennes; a work which, in so many respects, must always
serve as a model to labourers in this department of zoology.
The colours, in the great majority of instances, were, fortunately, noticed by
Mr. Darwin in the recent state. The nomenclature employed by him for the
purpose is that of Patrick Sym e; and he informs me, that a comparison was
always made with the book in hand, previous to the exact colour in any case
being noted. Where I have observed any markings left unnoticed by Mr.
Darwin, I have added them myself; and, in most instances, I have given the
general disposition of the colours as they appear in spirits, from the circumstance
of their being often so much altered by the liquor, and liable to mislead tliose,
who have only the opportunity of seeing them in preserved specimens. This is
what Cuvier and Valenciennes have frequently done in their work; and from
them I have borrowed the practice.
In a work of this nature, it has not been thought desirable to enter into any
discussion of the principles of scientific arrangement, or to effect any change in
systems already received ; its main object being the description of species. For
this reason, I have taken the groups almost exactly as they stand in the “ Histoire
des Poissons” of Cuvier and Valenciennes, or in the “ Regne Animal” of tlie
form er: yet there is reason to believe that many parts of their system will be
found hereafter to require some modification, especially in regard to families and
genera which have for their distinctive character the presence or absence of
vomerine or palatine teeth. The small value which is to be attached to such
character is pointed out in some instances in the following work, and much
dwelt upon.
In conclusion, it may be stated, that the whole of the species in the collection
of fiah brought home by Mr. Darwin, described in the following pages,
have been deposited by him in the Museum of the Philosophical Society of
Cambridge. They are mostly in spirit, and, generally speaking, in a good state
of preservation; some few, however, are in the state of skins only, and have
been mounted.
L. JEN Y N S.
Swaffham Bnlheck,
Jan. 8, 1842.