to 
=] 
=) 
clusions... Whether the name Laramie shall be restricted to the lower of 
the three divisions found in the Denver basin and its equivalents eise- 
where, as proposed by Cross and Eldridge, Knowlton and Peale; ‘or to 
one or both of the upper divisions, as advocated by Veatch; or retained 
to designate all the formations between the Fox Hills and the Fort Union; 
or wholly abandoned, is yet to be settled; and with this I have nothing to 
do. It is the purpose of the present paper to show that those deposits that 
lie above the Fox Hills and are known to contain remains of dinosaurs; 
more specifically the Laramie, as understood by Cross and Hldridge; the 
Arapahoe and the Denver of Colorado; the Lance Creek, or ‘“Ceratops,” 
beds of Converse County, Wyoming; the Hell Creek beds of Montana; 
and the beds underlying the Puerco in New Mexico, ought not to be re- 
ferred to the Tertiary, but to be retained in the Upper Cretaceous. 
2. NECESSITY FOR ACCURATE CORRELATION OF THE PRIMARY DIVISIONS OF 
THE GEOLOGICAL COLUMN IN THE DIFFERENT CONTINENTS. 
It appears to the writer that it is a matter of great importance that 
the primary divisions of geological time, the ages and the periods, and the 
corresponding systems of rocks of all parts of the world should as far as 
possible coincide. By this is meant that geologists should not (to employ 
an illustration) include in the Lower Cretaceous any deposits of one con- 
tinent that were being formed synchronously with Jurassic deposits of 
another continent. Nor ought they to include in the Tertiary of America 
any formations that are the time equivalents of European Cretaceous for- 
mations. It may be a matter of great difficulty to attain agreement in 
some cases, but it ought to be resolutely striven after. And in this con- 
nection the writer indorses fully the quotation made by Mr. Cross (Proc. 
Wash. Acad. Sci., xi, p. 46) from Dr. C. A. White’s address. It may be 
added that modification of the primary divisions ought to be made by in- 
ternational bodies of geologists and paleontologists. 
The reasons why the primary divisions of geological history should be 
fixed as accurately as possible, even though arbitrarily, seem to be simple 
enough. Geology is the history of the development of the earth and its 
1 Veatch, A. C., Amer. Jour. Sci. (4), xxiv, 1907, pp. 18-22. 
Cross, Whitman, Proc. Washington Acad. Sci., xi, 1909, pp. 27-45. 
Knowlton, I’. H., Washington Acad. Sci., xi, 1909, pp. 179-238 
Stanton, T. W., Washington Acad. Sci.. xi, 1909, pp. 239-293. 
Peale, A. C., Amer. Jour. Sci. (4), xxviii, pp. 45 58. 
