80 FLORIDA GEOLOGICAL SURVEY ELEVENTH ANNUAL REPORT. 
VEGETATION. 
The rolling uplands of the northern part of this area, although 
largely cleared at the present time, supported originally a mixed 
timber growth, including short-leaf pine and many hardwood de- 
ciduous trees, such as red oak, live oak, hickory, dog-wood and 
magnolia. The chief timber growth of the lands in the southern 
part of the area is the long-leaf pine. In the flatwoods the under- 
growth associated with this pine is chiefly saw-palmetto. In the 
well drained areas the undergrowth consists largely of the black- 
jack oak. 
When studied in detail the vegetation of this area may be di- 
vided into several more or less well-marked vegetation types, and 
in his report on the vegetation of northern Florida, published in 
the Sixth Annual Report of this Survey, Dr. R. M. Harper has in- 
dicated eight vegetation types within this area. The plants charac- 
terizing each type are there listed. 
ELEVATIONS. 
The only precise levels available in this area are bench marks 
established by the U. S. Army Engineers. These are placed on the 
west bank of the Apalachicola river in Jackson county. In addi- 
tion to these precise levels the profiles and levels of railroads have 
been available in determining elevations. The profile of the At- 
lanta and St. Andrews Bay railway, shown on a map accompany- 
ing this report, was made possible through levels obtained from Mr. 
Arthur Pew, Civil Engineer, Atlanta, Georgia and Mr. B. W. 
Steele, President, Dothan, Alabama. All levels obtained have af- 
forded material assistance in the study of the topography and geol- 
ogy, and the writers wish to express their appreciation of the as- 
sistance thus received which has very much facilitated the prepara- 
tion of this report. 
The following is a description of the bench marks that have 
been established upon precise level within this area. 
About two miles west of River Junction, 65 meters west of west concrete 
pier of Louisville and Nashville railroad bridge over the Apalachicola river, 
1 meter north of trestle, bench mark is the top of a copper bolt set in a con- 
crete post.' Elevation, 63.786 feet. 
