47 
of the shore-line. Off the western end, the water soon becomes 
from eighteen to thirty feet deep, but to the north and east it is 
very shallow and at low tide one can easily wade out several rods 
from the shore, and, in fact, at the eastern end, can very nearly 
wade to the next “key.” Here, then, are excellent opportuni- 
ties for finding the algae where they actually grow. The ordi- 
nary rise and fall of the tide is only two or three feet, and, as in 
Bermuda, comparatively few of the marine plants grow between 
the tide-marks, but from the low tide line outward to a depth 
of several fathoms they are found in great profusion. On the 
Fic. 4. Coralline Seaweeds ( Zithothamnion), from Key West. 
southern side considerable masses of sea-wrack were found cast 
ashore, consisting, at the time of my visit, chiefly of species of 
Laurencia. Certain other kinds of seaweeds growing off this 
same shore in great abundance were not cast on land at all or 
only in small quantity. Some which otherwise would have been 
missed were obtained by locating them from a boat with the aid 
of a water-glass, after the manner of the sponge-fishers, and then 
securing them by using along-handled rake. Nothing further in 
the way of dredging was attempted. A striking feature of the 
marine flora of Key West, though not usually perceived unless 
