AGASSIZ: THE FLORIDA ELEVATED REEF. 41 
indistinet location of secondary sounds and sinks as may be indicated by 
the many spurs and tongues, and islets and shoals, or long irregularly 
shaped finger-like tongues of land, whieh abound in Barnes Sound, and 
to the east all over the flats of the Bay of Florida. In many cases the 
former connection of the keys with the mainland is only to be traced 
from the innumerable small isolated islands scattered over the Bay of 
Florida, in a line from Long Key to Cape Sable. In the part of the Бау 
of Florida to the westward of that line, as far as Pine Keys, the man- 
grove keys and islets, the remnants of the former easterly extension 
of the mainland, have disappeared, while the group of keys to the west- 
ward of a line passing through Dahia Honda (Plate XV.) attests the 
former eastern extension of the peninsula of Florida, which has disap- 
peared through the same process now seen so actively at work in the 
district to the north of the outer line of keys from Long Key to Key 
Biscayne. 
Sounds similar to those so prominent on the northeastern extremity 
of the chain of Florida Коув — viz. Barnes, Card’s Sound, and Key Bis- 
cayne Bay (Plate XII.) — are repeated on a smaller scale from the Pine 
Keys to Key West as far as the Marquesas. An examination of the 
charts (Plate XV.) will show on many of the Pine Keys, Saddle Bunch 
Keys, Boca Chica, and Key West the mode of formation of smaller 
sounds; the disintegration of the larger islands leaving sometimes 
diminutive islands, or only narrow insular strips or angular spits and 
projections as remnants of the islands formerly limiting the sounds. 
These small and irregular sounds all discharge by so called creeks, 
Pelot's Creek, Sugarloaf Creek, and other outlets, which allow the piled 
up waters to escape and carry out the products of their disintegration 
of the island due both to solution and to mechanical action. 
With the exception of Pine Keys, the surface of the keys from the 
Marquesas to Key Largo is but indifferently wooded (Plates II., 111.), 
the vegetation consisting principally of a luxuriant fringe of mangroves 
(Plate IX.) and of low bushes, with occasionally a tree of larger size. 
On Key Largo and to the northward the trees are of larger size 
(Plate IV.). 
Perhaps the most instructive part of the Florida Keys regarding the 
formation of sounds is that part of Key Largo (Plate XII., and Coast 
Survey Chart, No. 167) where we find the spurs indicating its former 
connection with the mainland, forming on the one side Barnes Sound 
and separating it from Card's Sound, and on the other Blackwater 
Sound, flanked on the east by Barnes Sound, on the north by three 
