TrHE ARTESIAN WATER SUPPLY OF EASTERN FLORIDA.

thirty miles, then turning again flows a little south of east to the Atlantic Ocean. Nassau is one of the smaller rivers and with its tributary, Thomas Creek, forms part of the boundary between Nassau and Duval Counties.
Bordering the streams, both the main rivers and their tributaries, are found in many places, open flat, imperfectly drained pine lands. These lands are classed in the section treating of soils as open flatwoods. A somewhat different and more extensive type of country is that designated as palmetto flatwoods. An essential difference in these two types of country is the presence or absence of the saw palmetto, the pine forest being common to both. The palmetto flatwoods is the prevailing type of country throughout the southern part of this area. In Nassau and Duval Counties and along the tributaries of the St. Johns River extensive areas of open flatwoods occur.
Along the border of the uplands back from, the river and from the coast a different type of topography has developed, consisting largely of the sandy or rolling pine type of soil although scrub hammock lands occur. These several types of country are due to a considerable extent to the drainage conditions. On the summit of the plateau in the interior of Florida, palmetto flatwoods and to some extent open flatwoods are again encountered.
THE LAKE REGION.
The lake region is a term that has come to be applied in Florida tc a characteristic type of topography. The term does not refer merely to a section in which lakes occur, but is restricted in usage to apply to a section in which a particular type of lakes occur. The lake region consists of irregularly placed hills which descend abruptly to circular lakes. The soil is prevailingly sandy and well drained. There are few if any. surface streams, and the lakes have, as a rule, no surface outlet.
The lake region type of topography occurs in those parts of the State in which soluble limestones, although buried to a considerable depth beneath other formations, nevertheless lie sufficiently near the surface to affect the topography. In that part of the State in which limestones lie at or very near the surface large lakes rarely occur, although sink holes are frequent, some of which may contain water forming small sink hole lakes. On the other hand where the soluble limestones are so completely buried beneath other formations as to have no effect on .the topography lakes of this type do not occur..

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