SECOND ANNUAL REPORT—SOUTHERN EEORIDA. 223 
The writer groups all the west coast non-oolitic limestones show¬ 
ing marine fossils as a single formation, although they vary consider¬ 
ably in appearance. 
Stratigraphic Position:—These limestones underlie the gray sands 
of the mainland, the marls of the coastal swamps and the keys of the 
southern portion of the Ten Thousand Islands. They also extend 
along the southwestern border of the Everglades. Their relations to 
the non-oolitic marine limestones designated as Palm Beach limestone 
cannot be determined, the great saw-grass swamp of the Everglades 
separating the nearest exposures. The minimum interval between 
outcrops is about thirty-five miles. The relation to the Miami oolite 
cannot be determined with exactness, though from samples collected 
along the Florida East Coast Railway between Eong Siding and Jew- 
fish Creek, the writer believes that the oolite is younger than the non- 
oolitic limestones which lie south of it. Outside the shore-line of the 
mainland, the rock lies below sea level, and its relation to the Key West 
oolite across the Bay of Florida has not been established. 
A well drilled through the rock at Everglade showed that the 
limestone rested there on a fine gray sand. It is uncertain whether or 
not the limestone was struck at Marco. Possibly it was not and the 
limestone may be represented there by unconsolidated quartz sand and 
shell fragments. 
Lithologic Characteristics:—The Postmans River limestone varies 
so greatly that it is impossible to give a description that contains feat¬ 
ures common to all localities. At the type locality on Postmans River, 
the rock is described by Dali as very hard and consisting of large 
masses of Polyzoa more or less completely changed into crystalline 
limestone. The cavities are filled with crystals of calc-spar. Hand 
specimens show individual crystals an inch long. All the samples col¬ 
lected by the writer from Postmans River and from below water level 
in Allens and Turners Rivers had common features. Near Deep Lake 
the rock is softer and more friable. Rock from the head of Hender¬ 
sons Creek contained much more sand than specimens collected to the 
south, and in samples collected at several localities in White Water 
Bay from its mouth to its eastern extremity, a distance of nearly twenty 
miles, the proportion of quartz sand in hand specimens is very small, 
and microscopic sections show sand but rarely. Between Jewfish 
Creek and Manatee the rock is much less crystalline than on the west 
coast or toward the entrance to White Water Bay. 
Thickness:—The formation is probably thin. The well at Ever¬ 
glade went through but thirty feet of it. A boring at the plant of the 
Minette Lumber Company near the mouth of Shark River penetrated 
over forty feet of hard rock. 
