148 BULLETIN OF THE 



fully formed along the coast where the Everglade waters discliarge, 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 uo 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 cai'ried forward in an exceedingly 

 rapid manner. That a moi'e 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 Floiida 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 Eock 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 tliat 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 tlian 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 \Yorth. 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 uo 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 

 depai-ts from the shore near Fowey Rocks. Its warm, life-giving waters 



