308 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT. 
grass ponds, as well as the lakes and clear water ponds of the county, 
have probably resulted through the formation of basins by the solu¬ 
tion. of underlying limestone. 
The Leon fine sand is a fiatwoods type occupying a position slight¬ 
ly elevated above the Portsmouth fine sand. It is excessively drained, 
except at times of heavy rainfall, when it is usually covered with 
water. The objectionable hardpan is present, which adds to the 
low productiveness of the soil. Longleaf pine, scrub palmetto, wire 
grass, and “oak runners” constitute the characteristic vegetation. 
The Fellowship series, represented only by the fine sandy loam, 
occupies a position in the fiatwoods similar to that of the Portsmouth 
fine sand. The surface, dark with organic matter, is underlain by 
orange and ocherous fine sand, grading into similar colored fine 
sandy clay. Beneath this is found shell fragments and shell lime¬ 
stone. The material, of the subsoil at least, may be partly residual in 
origin. The marly character of the subsoil of the Parkwood soils 
is thought to represent a more advanced stage in the decomposition 
of the underlying marine deposits than is found beneath the Fellow¬ 
ship fine sandy loam. The vegetation is the sarnie as on the Fellow¬ 
ship and Portsmouth soils. 
The Plummer fine sand occupies low, flat semiswampy areas 
which are at present of no agricultural value. Water stands on the 
greater part of the type much of the time and cypress is the main 
tree growth. In many respects the Plummer fine sand closely re¬ 
sembles the more recent deposit of Tidal marsh, which is still in pro¬ 
cess of formation, and may be closely related to it in origin. 
In mapping Swamp the classification has been confined to low- 
lying areas along stream courses and bordering the larger bodies of 
fresh water. Swamp material varies considerably, but a great deal 
of it consists of areas of muck and peat too low lying and wet to be 
of any value in their present condition. 
Coastal beach is a self-explanatory term. It consists of sand and 
shells and is unsuited for agriculture. 
Including Coastal beach, Tidal marsh, Muck, and Swamp as 
types, ii types of soils were mapped, and several type phases were 
recognized. 
The following table gives the name and actual and relative ex¬ 
tent of each soil mapped in Pinellas County: 
