280 
FLORIDA GEOLOGICAL SURVEY—THIRD ANNUAL REPORT. 
The Cladium, Enpcitorium and Sagittaria are especially charac¬ 
teristic of the marshes bordering the lake, while most of the other 
herbs grow along the bayous in the swamp. Most of the plants in 
this list have already been mentioned as characteristic of calcareous 
swamps. 
The peat in the marsh, as far out as I was able to go, was about 
20 feet deep, which is considerably above the average. In the 
swamp at the point tested, which was where the railroad crosses 
one of the bayous, the peat was so full of logs that it was difficult 
to push a sounding instrument into it very far, but it seems to be 
at least 12 feet deep. 
In both swamp and marsh the peat is brown, moderately coarse, 
with a slight sulphurous odor. A most interesting feature of this 
peat is that it contains numerous univalve shells (a fact which was 
discovered by Dr. Sellards about four years ago). The shells are 
especially abundant in the bayous, at depths exceeding four feet. 
A small sample of this material from 6 feet below the surface 
of the water (which was only a few inches deep) in one of the 
bayous, collected April 23, 1909, was examined by Dr. W. H. Dali 
of the U. S. National Museum, with the assistance of Dr. H. A. 
Pilsbry of the Philadelphia Academy of Natural Sciences, and a list 
of 15 shells, including one new species, found in it was published 
by Dr. Dali in The Nautilus for May, 1910. On May 16, 1910, 
I collected a larger quantity of peat from the same spot, at a depth 
of 4 to 5 feet, and in this the following species have been indenti- 
fied by Bryant Walker, Esq., of Detroit, Mich. 
' • '■/ • 
Amnicola angustifia Pilsbry 
Amnicola Floridand Frfld.? 
Amnicola Harperi Dali 
Amnicola Sancti-Johannis Pilsbry 
Amnicola sp. 
Amnicola sp. 
Ampullaria sp. (very young) 
Ancylus obscurus Hald. 
Gillia Wctherbyi Dali? 
Goniobasis catenaria Say (G. pap 
illosa A nth.) 
Lymnaea ccdumella Say 
Paludestrina acquicostata Pilsbry 
Paludestrina monas Pilsbry 
Physa Cubensis Pfr. 
Pisidium sp. 
Planorbis Alabamensis avus Pils¬ 
bry 
Plan or bis dilatatus Gld. 
Planorbis parvus Say 
Planorbis trivolvis Say 
Planorbis tumidus Pfr. 
Polygyra sp. 
Succinea sp. 
Vertigo ovata Say 
Vivipara Georgiana Lea? 
Vivipara Haleana Lea 
All or nearly all of these are said to be found still living in 
Florida, so that their presence in this peat deposit does not indicate 
