74 
PALEONTOLOGICAL GEOLOGY 
Cretacic types, is no sign that we ourselves are actually living 
in the Cretacic time. Yet, this very thing is what we are asked 
to admit in the Cannonball controversy. 
Implicit reliance upon palegeographical maps is particularly un¬ 
fortunate and unconvincing. None of these maps up to the 
present time are constructed upon a modern physiographic basis. 
Hence they are largely not only almost incomplete, but, what is 
more serious, they are usually highly misleading. Their support¬ 
ing evidence in the case under consideration is necessarily entirely 
negatory. 
On the other hand, the ultra-conservative policy of the United 
States Geological Survey in geological classification is equally 
unfortunate. In waiting for the very last word in age determina¬ 
tions laudable advancement is lost sight of. This laisez faire 
method already puts the Federal bureau far behind the times. 
Normal forward movement is impossible. 
To one who has seen the Cannonball terrane only by gas-light 
its stratigraphic problems seem to present no very great difficulties. 
Its diastrophic measurement appears relatively easy, and, more¬ 
over, harmonizes perfectly the conflicting lines of biotic inference. 
The Lance formation, of which the Cannonball member has al¬ 
ways been regarded as the uppermost division, rests on a marked 
erosion unconformity. 
This stratigraphic break appears to have very large value, as 
Doctor Cross suggests, instead of small importance, as Professor 
Schuchert assumes. It seems to have very wide expanse; and to 
be represented in force on the Rocky Mountain front, where it is 
known as the Laramian Hiatus, and where a mile-high pile of 
strata are destroyed. There it marks the undoubted base of the 
Tertiary succession, a great basal section of which is older than 
any other Eocene beds that we know on the continent and perhaps 
in the world. 
In such an Eocene sequence it does not seem out of usual order 
that there should be at some time or other an incursion of marine 
faunas which would leave their impress along an old temporarily 
advancing seashore. Settlement of the Cannonball question sup¬ 
plies the basis for all modern terranal classification. It is probable 
that this will be done eventually upon other than paleontologic 
principles. Keye;s. 
