List of Crustacea Cladocera from Madison , Wis. 
397 
THE CONE-DREDGE. 
The dredge which I have used for collecting seems worthy of special 
description. It consists of four parts: the body, the cone, the net, and 
the screw-top. The body is a cylinder of stout tin, strengthened by a 
wire at each end, four inches long, and four inches in diameter. On 
top of this is placed a cone of brass netting, five inches high. This is 
attached below to a circle of tin so that it fits into the top of the body 
like the cover of a tin pail. The bail of the body is of stout brass wire; 
the ends passed through the side of the body and enlarged, and the 
loop of wire shaped so as to fit within the cone and project through a 
hole in its top with an eye into which the dredge-line can be fastened. 
To the end of the line is attached a snap-hook larger than the hole in 
the top of the cone, so that the cone can not come off the body when 
in use. There are two cones provided for my dredge, one of one-tenth 
inch mesh, and the other of one-twentieth inch. 
The Jjy inch mesh is coarse enough unless it is desired to secure very 
large forms. For ordinary shallow water collecting it is the best size. 
The cone can easily be removed for work at night in the open water. 
The net is of fine cheese cloth, eighteen to twenty-two inches long, 
conical, large enough at the base to slip over the dredge body, to which 
it is tied. It is faced with stout muslin for a distance of two or three 
inches at each end. At the smaller end it is small enough to fit the 
screw-top, a tin cylinder one inch in diameter and one and one-quarter 
inches in length, with a wire in one end and on the other a zinc 
screw-top, such as are used on kerosene cans. 
The seam along one side of the net is so made as to leave a sort of a 
loop in the cloth, through which a string can be run. One end of this 
string is tied about the dredge body; to the other end can be attached 
a weight, when desired, without having the pull of the weight come on 
the net. 
This dredge is very useful for collecting small animals in shallow or 
weedy water. It can easily be thrown from the shore to a distance of 50 
feet or more, thus permitting much more extensive collecting from 
shore than does the ordinary hand net. It can be drawn through weeds 
and over muddy bottoms, straining large amounts of water without 
becoming filled with mud or clogged with weed. If it is desired to col¬ 
lect from water close to the bottom without obtaining mud, a weight 
fastened to the end of the cord spoken of, so as to drag behind the 
dredge will cause the dredge to lift at each pull and so exclude most of 
the mud, except in very deep water. If a band of cloth is fastened 
about the base of the cone, leaving only the upper part free it will ad¬ 
mit the water just above the bottom without scraping up mud. An old 
rake or other irregular piece of iron fastened to the dredge-line in front 
of the dredge will stir up the bottom and thus samples of bottom ani- 
