9 
AGASSIZ: THE FLORIDA ELEVATED REEF. 83 
Rodriguez and Tavernier Keys. At these points the elevated reef did not 
rise more than about twelve inches above high-water mark, and presented 
the same pitted and honeycombed appearance which characterized the 
elevated reef elsewhere. Тһе reef rock was full of pot-holes, and we 
recognized as forming a part of the elevated reef blocks of the same 
species of Orbicella, Meeandrina, Astron, and Colpophyllia characterizing 
the elevated reef elsewhere. The elevated reef shelves very gradually to 
the eastward, and at a distance of nearly half a mile from the shore we 
could recognize.it below water. 
In order to determine, if possible, the width of the elevated reef, a 
seotion was made across Key Largo extending from the low shore line 
of the elevated reef to the east of Sound Point, at right angles to the 
trend of the coast. Specimens were collected every 500 feet, and it was 
found that the elevated reef extended about 3,000 feet from the shore. 
Jeyond that point the rocks collected seemed to indicate an жоПап 
formation blown into a shallow sink behind the elevated reef, much as 
we observed it on some of the other keys, as at Key West, Boca Chica, 
the Marquesas, and others, where the elevated reef has either been 
eroded, or has been completely hidden by the sand thrown upon and 
over its surface from the shore line and adjacent flats. 
This would seem to indicate a probable width of the Florida reef at 
that point of at least nine miles from the outer reef patohes, a width 
of reef patehes without parallel in any other coral reef district of the 
West Indies. 
''he elevated reef erops out again near the eastern extremity of Elliott 
Key (Plate ҮШІ). Its highest point is from five to six feet above 
high-water mark. The part of the island where we landed is interesting, 
as showing next to the elevated reef a small beach of coral sand over- 
lappin the reef (Plate IV.). Judging from the aspect of the keys as 
we steamed along, the reef alternately crops out or is covered by coral 
sand, forming beaches in low places, or banks alternating with clusters of 
mangroves and strips of land behind the elevated reef, separating the 
inner sounds from the waters bathing the southern shores of the keys. 
The elevated reef is pitted, honeycombed, and full of pot-holes. From 
what we have seen thus far the impression is produced that the outer 
line of keys were once a part of one extended reef or patéhes of тесі, 
which formed a fringing or an edging reef off the southern edge of the 
peninsula of Florida, and that the reef was subsequently elevated, and 
the land thus raised eroded by the combined action of the rain and of 
the sea. The process must have been very similar to that which gave 
