504 HE. C. CASE 
Conemaugh. In West Virginia, Hennen found the cast of a bone 
comparable only with Pareiasaurus in red shales about 200 feet 
below the base of the Monongahela series. 
Dr. I. C. White has long contended that the sudden appearance 
of the red sediments in the Conemaugh marks the beginning of a 
new geological period with changed conditions of environment 
and sedimentation. The red deposits continue in Pennsylvania 
and West Virginia more or less dominantly to the top of the 
Dunkard. Farther to the north the red sediments, tillites of the 
Boston basin, the New Glasgow conglomerate and the red con- 
glomerates, and shales and sandstones of Prince Edward Island 
are certainly well up in the late Paleozoic. Sayles and Mansfield 
have demonstrated the glacial origin of the Squantum tillite, and 
Bell has shown that the New Glasgow conglomerate is due to an 
elevation somewhere to the southeast. 
These local proofs of elevation are but contributory evidence 
of the commonly accepted elevation of the whole eastern part of 
North America, probably as a continuation of the same movement 
which formed the Hercynian chain somewhat earlier in Central 
Europe. The elevation of North America which began on the 
eastern side was gradually extended to the west, as is shown by 
the progressive disappearance of the Mississippian sea and the 
Pennsylvanian coal swamps in that direction. 
The elevation was attended by a gradual change in climate; 
instead of gray and black shales and white sandstones the prevail- 
ing deposits were colored red by the oxidation of the iron under the 
influence of a less equable climate, as seasons of relative drought 
and humidity succeeded each other. 
As this climatic change migrated toward the west only slowly, 
red sediments were formed at progressively higher and higher 
levels. In western Kentucky, Indiana, and Illinois the conditions 
necessary for the formation of red beds did not arrive until after 
the highest sediments now preserved had been formed, or only 
thin deposits were formed which have since been removed by 
erosion. ‘That the surface on these regions was dry land by the 
time ‘‘Permo-Carboniferous conditions’’ (formation of red beds) 
had reached them is suggested by the mode of occurrence of the 
vertebrates in Illinois and the Merom sandstone in Indiana. 
