Harring and Myers—The Rotifers of Wisconsin. 649 
inches. The finished net should be sewed to a metal ring with 
a socket (text fig. 1) for attachment to a pole or to a jointed fish¬ 
ing rod of the stout marine type; this can be taken apart and 
packed in a small space. A wide-mouthed bottle or an aluminum 
Text Pig. 1.—Collecting net. 
centrifuge shield of 50 cubic centimeters’ capacity should be at¬ 
tached to the lower end of the net; the centrifuge shield is more 
satisfactory, as it will not break on coming in contact with stones, 
tree-stumps, etc. The concentrated portion of the collection should 
be poured through a metal strainer which will allow the rotifers 
to pass through but will keep out the larger organisms, plants, 
and trash; 40 to 60 meshes per inch is a very suitable screen. 
By far the largest number of species of rotifers are to be found 
among the leaves of submerged plants; in such places the net 
method of collecting is rather inefficient, and far better results 
are obtained by simply bringing home the plants. Several bottles 
should be about half filled with plants, without crowding, holding 
the bottles close to the surface of the water while filling in order 
