INTRODUCTION. _ liii 
division (Cambrian Series)—the classification and nomenclature have the undoubted right 
of priority. Fourthly, that the nomenclature is geographically consistent and true—the 
best (and the only good) types of the Cambrian Series being derived from the sections 
of Cambria. Lastly, that no other classification and nomenclature which have yet been 
proposed satisfy all (or so much as one) of the above four essential conditions. 
On a review of all the facts above described, and adopting the words made use of by 
myself in the Philosophical Magazine*, I can now affirm with unhesitating confidence, 
“that the scheme of classification, and consequently of nomenclature, given in the above 
Tabular View, is true for the whole Cambrian series,—that it is the only approach to a 
good analysis of this series which has yet been given—that it was worked out correctly by 
my own labours among the older rocks of Wales, and has the claim of priority—that 
it is geographically appropriate—that it is physically true, because it makes a break between 
the Cambrian and the overlying Silurian series where nature herself had made it—and 
lastly, that it is palzeontologically true, inasmuch as that break is followed by an immediate 
and great change of the fossil species. It is true, exactly for the same reason that Smith’s 
original classification and nomenclature (however uncouth and harsh sounding) of the Oolitic 
series was true—because founded on true sections backed by lists of fossils. It is true, for 
the same reason that Mr Prestwich’s analysis of the deposits above our chalk is true. 
Lastly, it is true, for the same reason that the classification and nomenclature of the “ Upper 
Silurian” rocks is true. Nor is there, in the past history of British geology, any example 
of a single group, or series of groups, which has stood its ground and been established, 
except on principles like those which I have, I believe, correctly followed, and by the test 
of which I am willing that the scheme of classification and nomenclature, above given in 
the Tabular View, should stand or fall. That it will stand, I have not the shadow of a 
doubt, so long as we adhere to our geographical nomenclature.” 
That it may be superseded, hereafter, by some more general and scientific classification 
which may embrace the old and new world, and in which all merely geographical and local 
names will disappear, is quite possible, and I trust probable: but such a speculation does 
not come within the limited views of this Introduction. 
Other Schemes of Classification and Nomenclature applied to the Cambrian Series. 
Before I had, for the first time (1822), entered on an examination of the older 
Paleozoic rocks of England, their characteristic Fawna was by no means entirely un- 
known, or without any illustrations in the old Woodwardian Museum. Many good 
collections had been made from the Dudley Rocks, and some of the species had been 
named. One of the most characteristic fossils of the calcareous flags of Builth and 
Llandeilo (the Asaphus Buchii) was well known to collectors; and (along with one or 
* Paper on the May Hill Sandstone and the Paleozoic System of England, Philosophical Magazine, Dec. 1854. 
