80 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT. 
under very exceptional circumstances can a formation be older than 
the latest of the fossils that it contains. 
The following section is found on the east bank of Peace River 
about three hundred yards up stream from the Brownsville Bridge, 
and one-half to three-quarters mile above the Mare Ci;eek section. 
1. Soil and incoherent gray sand------ 4 feet 
2. Yellow sand, somewhat indurated —-- 5 feet 
3. Fine black phosphate pebble, interbedded with sand, and containing 
also leaves, branches and partly decayed logs to water’s edge — 3 feet 
This exposure is clearly a river deposit, and can hardly be older 
than Pleistocene. From this exposure in addition to the decayed 
wood and leaves was taken the usual Peace Creek fossils including 
teeth of the elephant, E. columbi, tooth of the deer, Odocoileus, 
broken ribs and teeth of sharks and rays. 
Fig. 10 .—Chlamytherium humboldtii, left jaw, interior view. A tracing 
taken from Lund’s original illustration. One-half natural size. Introduced for 
comparison with specimens found in Florida. (2) Chlamytherium septentrionalis. 
Two teeth from the right lower jaw. At the left, the third tooth from the 
back of the jaw (presumably the seventh from the front) ; the grinding surface 
of the tooth measures 22 by 6 mm. At the center, the fourth tooth from the 
back, (presumably the sixth from the front) ; the grinding surface of the tooth 
measures 23 by 6 mm. At the right, median section through the fourth tooth 
from the back of the jaw, showing by diagrammatic section the cavity at the 
base of the tooth. All from specimen No. 1722, Fla. Geol. Surv. Natural size. 
From Vero, Fla. 
