220 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
red or brown loam hills, sandy and calcareous hammocks, flat pine woods, prairies, lakes, sink-holes, waterfalls, caves, and other curiosities. The flat pine woods are very similar to those of East Florida (described a few pages farther on), but are readily distinguished by the fact that they are always lower than the adjacent loamy hills, while those of East Florida are higher. In elevation above sea-level this region ranges from over 200 feet in some places along its northern edge to about 5o feet near some of the lakes and rivers.
Streams are not rare in some parts, but there is considerable subterranean drainage besides. There are quite a number of streams which rise near the northern and eastern edges of this belt, flow across it toward the Gulf, and disappear into the ground near the lower edge. The topography of the region is complex, and difficult to describe in general terms, but by considering a small part of the area at a time some of the more striking features can be pointed out.
In Gadsden County the topography is just about what would be produced by normal erosion, there being plenty of valleys and streams and no lakes or sinks. The red hills, with many ponds and few streams, and forests composed of hardwoods and shortleaf pines, culminate in the northern half of Leon County, and, extend eastward with diminishing relief through Jefferson and part of Madison. South of the Santa Fe River the red clay is scarcer, and in Marion County the belt under consideration is reduced to a ridge of high hammock, with sandy soil, limestone near the surface, and neither streams nor lakes.
Many if not most of the lakes in this region are of a peculiar type (unknown outside of Florida), flat-bottomed, with one or more sink-holes at or near their edges, by means of which the water is kept drained off most of the time, especially during the dry season.* Such lakes when dry are commonly known as prairies, though they have little in common, with the large flatwoods prairies of South Florida, except that they are treeless and subject to inundation at more or less regular intervals.
Conditions are not very favorable for peat in the Middle Florida hammock belt, on account of the paucity of streams and the frequent emptying of the lakes. There are, however, various kinds of swamps, some of which contain pretty good peat; and many of the lake-bottoms (or prairies) are dotted with saucer*This type of lake or prairie is discussed by Dr. Sellards in a paper preceding this.