230 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
fairly open valley for itself, which is in strong contrast to the deep 
gorge from which it just escaped. The numerous branches of the 
Tugaloo are busy draining and dissecting the adjacent upland sur¬ 
face, and even gnawing headward into the higher Chattahoochee 
level, gradually pushing the ragged Chattooga escarpment farther 
back to the northwest. 
(2) The Chattahoochee level .— That this represents a peneplain 
surface some 500 or 600 feet higher than the Tugaloo level, there 
can be no doubt. The surface is remarkably even, bevels across 
inclined crystallines in the same manner as does the lower level, but 
slopes gently down to the west instead of to the southeast. 
The Chattahoochee level is by no means so continuous in the 
Tallulah district as is the lower level, but is interrupted by such 
notable elevations as the Tallulah Mountains and other mountain 
masses to the north and west, while the streams on the lower level 
have eaten back into its southeastern border, rendering this border 
very ragged. The Tugaloo River even heads within this level, and 
several of its branches have cut deep gorges into it. Farther south¬ 
west this level is more continuous and more readily discerned. 
(3) The Chattooga escarpment .— As already indicated, this escarp¬ 
ment marks the place where the two peneplain levels “break joint,” 
its summit marking the eastern edge of the upper level, its base the 
western limit of the lower level. Headward erosion of many streams 
located on the lower level has made this escarpment extremely irreg¬ 
ular, and there is every reason to believe that the continued work of 
these streams is pushing the escarpment gradually backward to the 
northwest, robbing the upper level of more and more of its area, 
and adding to the area of the lower level. To the southeast, in front 
of the present escarpment, are occasional hills, some of them flat- 
topped, which appear to be erosion remnants marking a former 
southeastward extension of the Chattahoochee level. How much 
farther southeast this level once extended I am unable to say, but 
there can be little doubt that it was a considerable number of miles. 
A traveler on the railroad, leaving Toccoa, which is situated on 
the Tugaloo level, soon begins to pass up the heavy grade to the 
west, by which the train climbs slowly to the higher level of the Chatta¬ 
hoochee peneplain. At New Switzerland this level is first fairly 
reached, while near Alt. Airy the important features of the topography 
are especially plain. Here the Chattooga escarpment (locally called 
