148 BULLETIN OF THE 
fully formed along the coast where the Everglade waters discharge, it 
seems to me there can be no question as to the relatively rapid excava- 
tion of the deposits of the Everglade district. There can be no doubt 
that this region shows in a very clear way how, under certain conditions, 
the process of excavating the interior of a plateau of limestone deposits 
may under favorable circumstances be carried forward in an exceedingly 
rapid manner. That a more distinct reef has not been left around this 
region of excavation is possibly due to the fact that this region has re- 
cently been somewhat lowered above the height to which it formerly 
attained. There is a good deal of evidence to the effect that the whole 
peninsula of Florida has undergone a subsidence of ten or twenty feet 
in altitude since the last period of elevation. 
It is commonly supposed that the living coral reefs of Florida cease 
at Key Biscayne, and that no true reef exists to the northward of that 
point. Although there is clearly no extensive development of reef de- 
posits north of Cape Florida, my observations, though limited, are suf- 
ficient to show that a distinct reef, essentially the continuation of the 
main reef of Florida, that on which Fowey Rock Lighthouse stands, ex- 
tends along the shore at least as far as Hillsborough River. In January, 
1888, I was so unfortunate as to have my boat capsized on the edge of 
the Gulf Stream, to the eastward of the mouth of that river. It was 
necessary to bring the boat ashore bottom upward by swimming beside 
it. Near the shore, there being a heavy sea on, we came upon a line 
of breakers, beneath which the water was not more than six feet deep. 
The effect of the surface of this reef on the bare feet of my party clearly 
indicated that it was composed of firm coral rock. Subsequent inquiry 
has shown that this reef is largely covered by living corals, including 
many Gorgonias and actinoid corals, mostly of the common species of 
Manacina, fragments of which are abundantly strewn along the beach 
all the way from Cape Florida to Lake Worth. Between Hillsbor- 
ough River and Jupiter Inlet the breakers show in times of storm the 
continuation of a lower reef near the shore, and the fragments of 
Manacina, often two feet in diameter, lying upon the beach, likewise 
afford evidence of a living reef in this section. North of Jupiter 
Inlet, my assistant, Mr. C. W. Coman, found fragments of Manacina 
scattered along the shore for a distance of twelve miles. Beyond 
this point, a careful search showed no trace of stony corals. The 
lessened development of the reef from Key Biscayne to Lake Worth 
is doubtless in part to be explained by the fact that the Gulf Stream 
departs from the shore near Fowey Rocks. Its warm, life-giving waters 
