434 BULLETIN OF THE BUREAU OF FISHERIES. 
sponge beds when, either by legal prohibition or from commercial considerations, 
they are wholly or partially abandoned for a few years. On most parts of this 
area the barry bottom is scattered and the water, which has a maximum depth 
of about ro feet, is frequently too muddy for work. 
Jewfish Bush lakes—These, known respectively as the upper and lower 
lakes, stretch from Jewfish Bush and Lower Matecumbe Key northwest to 
Schooner Bank, and produce limited quantities of excellent Key sheepswool. 
The bars are scattered and of comparatively small extent, and, particularly in 
the upper lake, the sponge growth is mingled with sea feathers and many kinds 
of noncommercial sponges. The water varies in depth between 6 and 1o feet, 
the deeper water being toward the northwest. 
In the summer of 1908 the sponge beds in this region and to the eastward 
were destroyed by “poison water.’’ It is probable that this was fresh water 
from the ‘Everglades, impounded by the railroad embankments of the ‘‘ Key 
West Extension.’”’ The closure or partial closure of the several channels - 
between the keys must result in the westward extension of the same density 
conditions which formerly prevented the growth of sponges inside of Key 
Largo, to which reference has been made before. 
Lignum-Vite and Cotton Key lakes.—These lie north of the Matecumbes 
and Lignum-Vite Key, are connected by Ironwood Channel, and almost sur- 
rounded by sand banks. The bottom of the former is almost all hard, and 
bears a scattered growth of sheepswool sponges and considerable quantities of 
other species. In Cotton Key Lake the rocky bottom is scattered and the 
growth consists mainly of grass sponges. In Lignum-Vitze Lake the depth is 
generally between 6 and 8 feet, while in Cotton Key Lake it averages about a 
foot less. The sheepswool and yellow sponges from these and the two lakes 
previously mentioned are the softest produced in Florida, making them especially 
desirable -for bath purposes; they are known to the trade as ‘‘ Matecumbe,”’ 
wool and yellow. 
The Cowpens are at the eastern limit of sponge growth inside the keys west 
of Cards Sound. They produce few sponges, and those found are usually rollers 
on the soft bottom. 
Biscayne Bay.—Cards Sound, which lies west of Biscayne Bay, contains a 
few yellow and grass sponges and an occasional sheepswool, but has never been 
of importance. There are also a few grass and yellow sponges scattered over 
Cutters Bank; which lies between the two bodies of water. 
Billies Lake, which lies in the southern part of Biscayne bay between: 
Cutter and Featherbed banks, contains a scattered growth of sheepswool, yellow, 
grass, and glove sponges, and it is stated that in that portion nearest Sands 
Key, which is at present the most productive, the growth was at one time 
prolific. It is probably now restricted by the number of small boats which 
