314 2'he American Geologist. May, 1895 
about 300 miles, which is about the same as the distance from 
Buffalo to Montreal, and it is in the same direction. Dr. Bell 
reports Pleistocene marine shells in stratified deposits overly- 
ing the drift up to more than 500 feet above the sea on the 
shores of Hudson bay, and on the Kenogami river up to 
within 150 miles of lake Superior. There is much reason to 
believe that the Hudson bay region, as well as the St. Law- 
rence valley and the Great lakes, was involved in the Cham- 
plain uplift. 
This attempt to identify the Nipissing beach in Prof. Law- 
son's work is not offered as final or conclusive. But it is 
believed that it is the best that can be done in the present 
state of our knowledge of the north coast of lake Superior. 
A HYPSOMETRIC MAP OF MISSOURI. 
By C. R. Keyes, Jefferson City, Mo. 
The elevations of the various points within the boundaries 
of Missouri are, as in the case of most other states of the 
Union, known only in a somewhat general way. The pub- 
lished information of this character by the different states is 
meager and is often restricted to a few scattered lists of rail- 
road elevations unrevised and usually started from some point 
other than sea level as a datum. The importance of having the 
zones of equal altitude more than approximately determined 
and the convenience of having all elevations referable directly 
to mean tide as a datum line is fully appreciated by all who have 
had areal geological work to do. Its fundamental necessity is 
recognized whenever detailed topographical mapping imme- 
diately precedes or acccompanies the tracing and investiga- 
tion of the various rock formations. In the majority of the 
states no careful topographical mapping has been undertaken 
under the official direction of their respective geological sur- 
veys. Most of the more exact relief work of this character 
which has been accomplished in this country has been under 
Federal auspices, though some of the states have carried on 
similar mapping but in co-operation with the topographical 
organization of the general government. Usually, then, when 
the elevations of the different parts of any district are con- 
