NATIONAL FISHERY CONGRESS. 
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nonproductive of marketable sponges if the weather and water were always favorable 
to the spongers, the preservation of the beds largely depending on the prevalence of 
storms or turbid water during some seasons or parts of seasons. 
The slieepswool is believed by many observers to grow the most rapidly of any of 
the sponges, but information on this point is not as complete or accurate as might be 
desired. Some experiments performed and observations made by gentlemen of Key 
West lead them to believe that this species may, under favorable conditions, grow 
from the beginning to one-tenth of a pound weight in six months. The opinion that 
this sponge will grow from the spat to good commercial size in one year is practically 
unanimous and seems to be verified by the sponging operations. The spongers all 
testify that grounds which were thoroughly fished out one year are found to yield 
large numbers of commercial sponges twelve months thereafter. 
The catch of the sheepswool in 1895 was fifteen times and in 1897 six times as 
valuable as that of all other species combined, and is thus sufficiently important to 
give prominence to the sponge industry, even if no other kinds were taken. The aver- 
age prices per pound brought by sheepswool sponges were $1.57 in 1895, $1.60 in 1896, 
and $1.53 in 1897. 
Of late, owing to a diminished supply, the relative catch of sheepswool sponges 
has been decreasing, cheaper varieties entering more largely into the receipts. In 
1895 the percentage of sheepswool sponges in the total catch was 76; in 1896 it fell to 
04, and in 1897 was only 47. 
THE VELVET SPONGE. 
This is an uncommon form, with a very limited distribution. Along the west 
coast of Florida it is rarely found, the yield coming almost entirely from certain 
grounds among the keys. It resembles the sheepswool in general structure, but has 
a smoother surface and finer fibers. The characteristic feature is the presence of soft 
protruding cushions, whence the name. It is also known as the boat sponge. Its 
shape is very irregular. Its average size is 7 or 8 inches in diameter, but the diameter 
of some is a foot or a little over. Its principal source of supply is the region adjacent 
to the Matecumb'e Keys, where it is taken on coral bottom in water from 15 to 20 feet 
deep. The grounds have undergone serious depletion, and smaller cargoes are landed 
each year. Velvet sponges are taken in smaller quantities than any other Florida 
sponges. In 1897 many dealers did not handle any, and the receipts in recent years 
have never exceeded a few thousand pounds per annum. The usual price paid by 
dealers is 50 cents a pound. 
THE GRASS SPONGES. 
There are at least two species comprehended under the trade name of grass 
sponge, and the individual variations are numerous. One species (called Spongia 
graminea by Hyatt) has a coarse, open structure, with deep furrows on the sides, in 
which the afferent channels always begin. The general shape is that of a truucated 
cone, with the larger openings always on top. The other grass sponge ( Euspongia equina 
cerebriformis) resembles one form of the yellow sponge, but differs in having its 
surface marked by parallel longitudinal ridges surmounted by two or three lines of 
tufts. In the depressions between the ridges the large efferent canals open, their 
orifices being in rows. Many forms of this species exist. The cup shape predominates. 
