me 
E. B. Hunt on the Florida Reef. 205 
ue to the interrupted nature of coral beds, whether 7n situ or 
formed of coral boulders and sand. 
site, within their proper range of depth, temperature and water- 
supply, which growth, by secretion, separates the carbonate of 
lime from the mass of the ocean and gulf water; 2d, the un- 
uring action of the winds, tides and currents (aided by borin 
shells), in breaking up, triturating, transporting and depositing 
3d, solidi- 
fication by time, pressure, segregation and possibly by chemical 
Operation of these agencies, as now at work, and from the 
ero to pass back over the past until that time when the 
lorida Bank did not exist, and when the shore from Cape Sable 
to Fort Dallas was the open ocean-front of South Florida. It 
Seems however not too audacious to say that the agencies now 
at work previo a general type of operation which requires but 
unlimited time to realize results no less than the formation, not 
only of the line of keys and reefs, but of the immense substruc- 
ture which rises from the great original plane of the gulf bed. 
This plane along the Cuban coast was over eight hundred fath- 
oms deep, and it could hardly have been less than three hun 
fathoms under the present Tortugas group. 
The evidence that South Florida and the base of the Bank 
have recently undergone neither elevation nor depression, to any 
Considerable extent, is quite convincing. There is a remarkable 
Coincidence of general level along the crescent of keys, and no 
Teliable evidence of vertical movement is found on any of t 
rof. Tuomey fancied he saw evidence of elevation through sev- 
eral feet at Key Vaceas.' Believing that he had mistaken bould- 
ers for masses in situ, I inquired of Assistant Hilgard, whose ob- 
servations on the keys during his surveying labors have been 
extensive, and he replied that he has “never seen any coral 
raised in situ above the water. He paid some attention to 
the subject, and remembers those at Key Vaccas particularly, 
Where he satisfied himself by using @ crowbar that they were 
boulders bedded in sand.” Prof. Agassiz and Prof. LeConte 
4 This Journal, 1851, vol. ii, p. 890. 
Am. Jour. Scr.—Srconp Serres, VoL. XXXV, No. 104—Maron, 1863. 
27 
