1897.] Geology and Paleontology. 527 
The data actually at the disposition of science are sufficiently num- 
erous to sketch the principal features of the great physico-geographical 
changes, such as the invasion of the oceans, the relations which exist 
between these and the general oscillations, ete. The reconciliation of 
these data with the faunal data could doubtless accomplish the admis- 
sion of a new grouping of geological systems, and put an end to the 
continual fruitless polemics, which ensue from the efforts one is obliged 
to make in order to bring into the frame work of the actual systems 
all the peculiarities which the various regions offer. It goes without 
saying that the discussion of this question of a general nature does not 
exclude the necessity of examining the propositions of the commission 
for the unification of the nomenclature ; but a satisfactory preliminary 
understanding would certainly contribute much to prepare the success 
of the deliberation on the propositions suggested by the commissions 
of Geneva and Manchester. 
After the examination of the first points it would be very desirable 
that a second question of principle should be cleared up, that of the 
rules to follow in the introduction of new terms in stratigraphic nomen- 
clature. Each of us knows how many new denominations appear in 
the literature to designate different geological divisions. Frequently 
the authors of the new terms introduce them without any argument, 
either batrological or faunal, which might serve to distinguish clearly 
the sediments to which they apply these denominations from the adja- 
cent deposits; it happens even sometimes that the authors themselves 
have very vague conceptions of what they call by anew name. Such neo- 
logisms appear not only in the special literature, but quite frequently in 
the manuals, whence they pass into the general literature. These new 
terms being evidently but a useless burden to the science, it is in the 
highest degree desirable that the Congress, which has already estab- 
lished rules to follow in the paleontological nomenclature, assert itself 
also on the question of the stratigraghic nomenclature, and that it 
establish data which may authorize the application of new denomina- 
tions to certain deposits. baht 
Another question of not less absolute necessity in the opinion of the 
Committee on Organization, is that of petrographic nomenclature, of 
which it is more than urgent to-day to establish the principles. 
The inundation of new terms in the science has attained such dimen- 
sions that very soon no human memory will be able to retain the whole 
mass of new denominations, and the reading of each memoir will neces- 
sitate the employment of a special glossary. The labors undertaken in 
‘this direction could be made simultaneously with the deliberations on 
