state at length the views of foreign authors, merely to show in
what respects I differ from their conclusions, or to detail their
systems only to illustrate my own departures from their methods
of arrangement, appeared to me less likely to serve the cause of
a branch of knowledge yet in comparative infancy, than to place
before the inquirer a series of observations for which I could
personally vouch, and thus to accumulate facts, at present so
scantily supplied, upon which the future student might rest a
more complete structure of theory and classification.
How far the present work contains materials new to the
English reader will be understood when I state, that of the 224
species included in the first sub-tribe, not more than twenty have
hitherto been recorded by our native observers ; and of the others,
a very large proportion are either for the first time described, or
can only be doubtfully referred to the outline figures given by
Elirenberg and Kiitzing, and rendered accessible to the English
reader in the pages of Pritchard’s History of Animalcules.
But the task I had assigned to myself would have been much
less productive of results had I not been aided by the frank and
cordial co-operation of fellow-inquirers, who, by the liberal communication
of specimens from other localities, have enabled me
to enrich my record with some of its most beautiful and interesting
forms. It is my pleasing duty to acknowledge the obligations
I thus owe to Mrs. Griffiths of Torquay, Dr. Dickie of
Belfast, Dr. Greville of Edinburgh, Professor Williamson of Manchester,
Mr. Edward Jenner of Lewes, and M. De Brebisson of
Falaise, whose entire herbaria in some cases, or in others ample
selections therefrom, as fax as relates to the Diatomace®, have
been placed at my command. I have, however, to regret that
these collections, with one exception, contain but few species in
the genera embraced in my first volume, and that in this exception,
which refers to the species from Ealaisc, the specimens
reached me at so late a period that I have been unable to use
them in the nomenclature of my plates, and could only employ
them in correcting and enlarging the synonyms given in the text.
Eor other specimens, and many of them in a living state, I
am indebted to gentlemen, whose favours I have recorded under
Ihe species they have respectively contributed. Among these
fellow-labourers I must not omit a special acknowledgment to
my zealous and indefatigable correspondent Chr. Johnson, Esq.
of Lancaster, who, by frequent communication of specimens collected
by himself and Mr. George Smith of Wray, and by the
liberal aid of books and translations, has contributed important
assistance.
Nor do I wish to leave unnoted the labours of my predecessors,
more especially those of Mr. Ralfs and Mr. Thwaites, to whom
IS due nearly aU that has been known of our British species of
Diatomaceae. How much is owing to the accurate and laborious
researches of Mr. Ralfs, will be better seen in my second volume,
which will embrace the greater number of the genera to which
he has directed his attention.
I have, lastly, to acknowledge the efficient assistance received
from my able coadjutor Mr. Tnffen West, whose accurate representations,
in every case faithfully drawn from nature, have
so materially enhanced the value of my work to the scientific
student, and conferred upon it much of whatever value it may
possess, in the estimation of the general observer.
As I have not admitted anything into my pages which I have
not verified by actual observation, I have abstained from recording
localities unless specimens have been seen and examined
by myself. In the uncertainty which attended the nomenclature
of species, and the imperfect means of identification open to the
English observer, this course was imperative.
I have departed from the ndc in one case only, Arachmidiscus