324 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT. 
In wet seasons the entire type is covered with water and not in¬ 
frequently water remains in the ponds the greater part of the year. 
There is no textural difference in the typical soil and that of the 
included ponds, but it is not uncommon to find the soil in the latter 
lighter in color. The ponds support a heavy growth of cypress, but 
in the less depressed areas the timber growth is more scattered and 
consists of mixed longleaf pine and cypress. The areas also support 
a good growth of coarse grasses. The slightly depressed areas 
which are narrow and winding closely resemble shallow stream 
channels and probably represent the floors of ancient lagoons or 
sounds. 
The hig'her lying areas of Plummer fine sand support a light 
growth of longleaf pine. A scattering growth of scrub palmetto 
is also present, but this is not characteristic of the type and occurs 
only where small areas of Portsmouth fine sand were of necessity 
included in the Plummer fine sand. 
Owing to poor drainage, none of this type is at present under 
cultivation, and in its present state it is of no 1 agricultural value 
except for pasture. 
BLACK SOILS. 
SEDIMENTARY MATERIAL-SANDS AND CLAYS. 
Portsmouth Series. 
The soils are dark gray to black, and are high in organic matter. 
The subsoils are light gray to mottled gray and yellow, and the 
heavier members are always plastic, though usually carrying a 
noticeable amount of sand. These soils are developed in flat to 
slightly depressed, poorly drained situations, and require ditching 
before they can be used for agriculture. The series is most exten¬ 
sively developed in the flat woods, or the low region of the Coastal 
Plain, east of the Mississippi River. 
PORTSMOUTH FINE SAND. 
The surface soil of the Portsmouth fine sand, as typically de¬ 
veloped, consists of a dark-gray or black fine sand, with an average 
depth of 10 inches and containing considerable organic matter. 
The subsoil is a light-grav fine sand, practically free from humus, 
passing at about 24 inches into a hardpan stratum. This layer some¬ 
times lies directly beneath the dark surface soil, while in other places 
it is either separated from the dark surface soil by a layer of gray 
