INTRODUCTION. Ixxix 
Cambrian Series, he ought to have made it typical, and based his nomenclature upon it. Even 
had he but published this suspicion, without the support of proof, he might perhaps have 
had the shadow of a claim to the publication of a prototype. But he did no such thing: 
and if his present views be conveyed by the above extract, they only prove how entirely 
at fault he was in his original interpretation of his own section. For he surely will 
not contend that he had a right to mean one thing by such words as Llandeilo Flag 
and Lower Silurian while he was in Caermarthenshire, and quite another thing when he 
was applying the same words to his rocks in the miniature tracts of the Shelve and the 
Stiperstones. To do this would only be to introduce (as I have said before) a palpable 
sophism. To call his miniature section a prototype is, therefore, a strange fallacy of language. 
It was neither a prototype, nor was it taken as a type at all when he included (in 1843) all 
Cambria in Siluria. Nor was it taken as a type by the Government Surveyors while they 
were endeavouring (though they had utterly destroyed the typical meaning of the Lower 
Silurian Sections) to sanction the extended Silurian nomenclature, by a monstrous and 
unnatural process of development of its groups, through the older regions of North Wales. 
The Cambrian Series of North Wales is the trwe prototype, both historically and geologically. 
I first made known this prototype; and no one has any right to tamper with it; unless 
where he can prove it wrong. If Professor Ramsay and Mr Salter can shew that certain 
obscure and difficult groups between the Llandeilo Flag and the Longmynd are the probable 
equivalents of some of the older subdivisions of the Cambrian Series, so much the better ; 
they do not thereby destroy, but confirm, the truth of the Cambrian prototype: and but 
for the evidence supplied by the typical Cambrian groups, the groups to the west of the 
Longmynd might have remained, to this day, in the same erroneous relations in which 
they were left in the “ Silurian System.” 
In leaving this chapter of “Siluria” I cannot but express my astonishment at its want 
of complete and fair historical statement, and consequently of conclusive argument. It is, in 
fact, a one-sided advocacy of that which is indefensible: plainly shewing, that however well 
informed, and armed at all points in his own Silurian country, my friend lost his strength 
when he wandered, unconsciously, beyond his true Silurian base. The Montgomeryshire 
sections, west of the Longmynd, are well deserving of study; and, classification apart, they 
are excellently described in the Silurian System. But when the author offers them as the 
prototype of the Cambrian Series he misdates their chronological place in the geological 
history of our Paleozoic rocks. And if he represent them as conveying, by themselves, the 
most distant conception of nature’s clear and grand development of the Cambrian series, 
he, thereby, either proves that he writes as an advocate, or that he writes on a subject 
he has not worked out for himself, and with which he is even now but imperfectly 
acquainted *, 
* Two very grave errors affect my friend’s reasoning in every part of the controversy. Ist, He assumes that he has a 
right to change his principles of nomenclature when he is dealing with his lower groups. 2ndly, That having committed a 
