E. B. Hunt on the Florida Reef. 203 
apparent that a westward extension of the reef must be slowly 
taking place. It would thus appear that the. keys, at least in 
their substructure, are rather results of the waste from the 
present line of reefs than an original and anterior reef growth. 
Concurring with this process is the growth of coral as now at 
ortugas, and in such heads or masses as can find foundation on 
the sand slopes of the keys. 
he solidification of the keys must be a slow and later process, 
and, some thousands of years hence, the sand masses of the Tor- 
tugas may assume an oolitic structure like that now seen at Key 
West. The calcareous marl, wherever found, seems to be pre- 
paring for solidification, and in a single instance of hard marl, 
from the eastern portion of Key West, I observed what could 
easily be fancied to be the circles of incipient oolitic segregation. 
The crystallization of the contained salt soon broke up.this ap- 
pearance, and I never again obtained it, though the confirmation 
of such an observation of oolite ab ovo would have great interest, 
12 Consideration of the vast masses of this rock in the earth’s 
crust. ‘That the finely comminuted white mud or marl solidifies 
. 
looking much like bones, but distinctly showing the spiral curl- 
Mg in the section. Most of the oolitic rock of Key n 
Wholly composed of oolite. The summit of this mound is about 
en feet above high water, and is believed to be the highest 
Point on the whole line of keys. The gale of 1846 raised the 
Water to within seven feet of the apex, and we can readily con- 
