INTRODUCTION. Ixy 
Nor were the consequences of this scheme only an inconsistent and unphilosophical 
nomenclature. All Cambria and Siluria must form one System. Therefore, on the scheme 
of the Survey, the oldest fossil-bearing rocks of Wales (under the name “Lower Silurian”) 
were linked to the true and undoubted groups of Siluria by a “Middle Silurian” group 
made up of the Caradoc Sandstone and the May Hill Sandstone. This link (the only 
support of the scheme which packed the rocks of Cambria and Siluria in one System) 
has now been broken; for it was not of nature’s workmanship: and the attempt at its 
fabrication showed the importance of a cautious adherence to fundamental principles; and 
also proved that excellent paleontologists and excellent field observers, even while com- 
bined together, may be greatly misled by a premature classification and nomenclature*. 
After his well-deserved triumphs, and the high honours gained in Russia, my 
friend seemed to aim at nothing short of a Palzeozoic Empire, over which the supreme 
authority was to center in himself. The highest collective group of the whole Palzozoic 
System must have a new name—Permian; and the symmetry of our English geographical 
nomenclature became disfigured by the interpolation of a foreign name, which put out of 
sight our own more perfect European typet. In pursuance of this commanding aim, the 
Silurian System was no longer a philosophic scheme worked out on principle and defined 
by admitted facts: but Siluria became a region undefined and expansible—capable of ab- 
sorbing within itself, right or wrong, all neighbouring countries which had with it any 
community of character or language. 
* While the May Hill Sandstone and the Caradoc Sandstone were regarded as one group, and called Middle Silurian, 
there was no motive for a nice separation of the fossil localities. At any rate, it is quite obvious that, in the collection of 
the Government Survey, the May Hill and Caradoc fossils must have been injuriously blended together. The collection 
made by myself had been formed without any hypothesis as to nomenclature, and with great care as to the localities. Hence 
(as has been above stated) Professor M°Coy was enabled from my collection (though far inferior to that of the Government 
Survey) to make the critical separation of the May Hill and Caradoc Sandstone, before he ever visited any part of Siluria. 
This separation was the very turning-point in the right interpretation of the physical as well as of the paleontological 
groups which enter into the structure of North and South Wales. 
As the classification and nomenclature of the Survey is hardly more or less than a following out of that which was 
advanced by Murchison in his map of 1843; the same objections apply to both. As I have succinctly stated the objections 
which I believe fatal to the scheme of the Government Survey, in one paragraph of a paper published by myself in the 
Philosophical Magazine of December last, I will subjoin them word for word to this note: though they are virtually but a repe- 
tition of the reasons above given against the unphilosophical and illogical extension of the published Silurian nomen- 
clature. They are as follows: ‘ Once for all, then, I confidently affirm, that the great Cambrian series is a natural and true 
series, and that its subdivisions have been rightly named in the above Tabular View. On the other hand, I contend that 
the classification and nomenclature of the same series in the scheme of the Government Survey are erroneous and untenable, 
Ist. Because it overlooked the true physical and paleontological base of the Silurian series. 2nd. Because its nomenclature 
is but an expansion of Silurian names derived from sections which were not true to nature. 3rd. Because no section, within 
the limits of Siluria, gives us a good older Paleozoic type. 4th. Because the nomenclature of the Cambrian series (as given 
in the Survey) was not deduced from the natural groups; but, on the contrary, the natural groups were so packed as to fall 
in with a previous (Silurian) nomenclature, which was based on erroneous sections. 5th. Because it introduces two different 
and incongruous schemes of nomenclature into one System, and consequently involves the nomenclature in most needless 
geographical contradictions and incongruities. There ought never to haye been any controversy on the questions I have 
been discussing ; and since the establishment of the May Hill Sandstone, there is now at least no shadow of reason for its 
continuance.” 
+ For the purpose of comparison with the corresponding rocks of France and Germany, our own highest British 
Paleozoic type is more perfect than the Permian of Russia. (Supra, note to p. xxyi.) 
