222 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
large enough to be called creeks, and probably 1o lakes. The soil is everywhere sand, and the ground-water is so near the surface that very little of the land is cultivated. The population is consequently sparse, and wells and other excavations zo rare that it is not easy to make a general statement as to what underlies !-,e sand. On the shores of Apalachicola Bay can be seen low bluffs of hardpan, a substance which looks like black sandstone but can be easily crumbled in the fingers,* and this probably underlies much of this region (and parts of some of the other flatwoods regions) at no great depth. The limestone which is supposed to form the foundation of all Florida' is not near enough to the surface in the Middle Florida flatwoods to have any marked effect on the vegetation.
The innumerable bays and ponds all contain some peat, but on account of the flatness of the country it is so shallow (hardly ever more than a foot or two in thickness) that it will probably be a long time before it can be utilized with profit. No samples have been taken from this region.
GULF HAMMOCK REGION.
(PLATES 17.2, 20.2, 21)
Between St. Mark's on the west and Tarpon Springs on the south, within about T5 miles of the coast, the country is mostly flat, damp and sandy as in the region just described, but differs from that in having limestone everywhere near the surface, and often cropping out. The greater part of Sumter County seems to be also of this character. The whole region, including the Sumi vl County portion, seems to be less than 75 feet above'sea-level
This is a somewhat more diversified region than the adjacent flatwoods above described, as it contains many low hammocks (of which the great Gulf Hammock of Levy County is typical), a few lakes, and some areas of undulating dry sandy pine larud (especially in Taylor County), hardly distinguishable from that of the lime-sink region. Although long-leaf pine is-the most abundant tree here, as in most other parts of Florida, there is a considerable variety of hardwoods in the hammocks and swamps.
The coast of the Gulf hammock region is unique. Islands and beaches are practically absent from it, but the ocean bottom slopes so gradually (only a foot or two to the mile in most places) thai large waves cannot approach the shore, and the effect is much the
*An analysis of this mnaterial can be found in the chapter on fossil peat.