Prof. F. W. Hutton — On Geological Nomenclature. 61 



and in time both may be shown to be equivalents of the "Gondwana 

 System" of India. If so, the earlier name would stand for the 

 Eegional System and the others would become synonyms. But it 

 would not therefore follow that the Cainozoic Systems of India and 

 New Zealand were equivalents ; each sj'stem would retain its own 

 name until it was proved to be the equivalent of some other. Some 

 systems would be quite local, others w^ould be widely spread. 

 Exactly the same method would be employed with the series com- 

 posing a system. Each would retain its own name until two or 

 more were united by palseontological evidence. Of course differences 

 of opinion would arise as to whether two series, or two systems, 

 should or should not be united. This is unavoidable in any case. 

 It is the same difficulty which naturalists have to deal with in 

 making species and genera. But it is no more, and probably a con- 

 census of opinion would soon settle each point. 



It may be objected that a great number of names would have to 

 be introduced, many of which would in time become obsolete. This 

 is true ; but on the other hand, applying the names of the rock- 

 systems of Europe to the systems in other parts of the world must 

 always be very inaccurate, and may lead to serious error. It is 

 better to multiply names if it insures accuracy, than to insure in- 

 accuracy by making a few names cover everything. An illustration 

 will render the comparative merits of the two methods clearer. 

 Suppose, then, the existence of a rock-system in Chili which in 

 reality covered in time part of the Jurassic and part of the Cretaceous 

 period. At first, when the knowledge of its fossils was slight, there 

 might be a difference of opinion as to its age. B}'^ the one method 

 some geologists would apply the name Jurassic, others Cretaceous to 

 it, so that confusion might easily arise. But when its true age came 

 to be known, a compound name, such as Cretaceo-Jurassic, would 

 have to be invented, and even then, this cumbrous name would not 

 be accurate, as the system would not cover the whole of these periods. 

 By the other method the system would at once be called (say) the 

 * Talca system,' and under this name it would always remain, unless 

 shown to be the exact equivalent of some other system. Its true age 

 would at first be disputed, but no confusion could arise, as no 

 chronological name would be applied to it. Ultimately this point 

 would be settled and the system referred to its proper place in the 

 universal scale. The name ' Talca system ' would also be accurate, 

 as it would include those particular rocks only, neither more nor less. 



It might also be objected that under the system here advocated it 

 would not be possible to colour geological maps uniformly ; but this 

 objection has no weight. It is impossible, in any case, to colour all 

 geological maps uniformly, because the regional systems overlap in 

 time. It would be no advantage to call a system Silurian, in order 

 that it might be so coloured, when we know that it cannot be the 

 equivalent of that European system. In the method I advocate the 

 colours would represent the chronological divisions of the universal 

 scale, and each system would be coloured as if it belonged to that 

 chronological division which most nearly represented it. 



