OF THE ALGuE GENERALLY. 
5 
2. A tiny sieve, such as is sometimes suspended from 
the mouth of a teapot to intercept the minute portions of 
the leaves. It must be of very fine wire, and provided 
with a handle. Its use is to secure floating masses of 
Desmidiacese, Limnochlids, &c. 
3. A common iron spoon is convenient for lifting with 
care the upper layers of mud, where there is reason to 
suspect the presence of Diatomaceas and Desmidiacege. 
4. Where Characeas are likely to be met with, or, indeed, 
for dredging purposes generally, Caspary’s rake is an 
Fig. 8. 
admirable instrument, fig. 8 . It is made of iron, and is 
of the following dimensions ; — Length, a, b , ten inches ; 
width, c, d , from the point of one tooth to the opposite 
point, three and three-quarter inches; distance between the 
points of the teeth c , e, three-quarters of an inch. The 
handle, f < 7 , terminating in a ring, to which a stout cord 
may be attached, is five inches long. The weight of the 
instrument must not be less than two or three pounds; 
if lighter, it is apt to jump over slight obstacles at the 
bottom of the water, and thereby miss the object to be 
caught. The length of line, which should be about the 
thickness of a finger, must of course be adapted to the 
depth of the water. An Alpine lake frequently requires 
as much as eighty or ninety feet. For convenience 
