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in this article as to the various haunts and seasons of the dif- 
ferent nymphs and imagos, will give one a pretty good idea what 
species may be found in the waters near at hand. Nymphs of 
species inhabiting vegetation may be secured with a dip-net or 
rake. The dip-net is quite an essential article. The kind most 
in use at the Biological Station has a D-shaped ring made of 
heavy wire about a quarter of an inch thick, the two ends joined 
at the middle of the curve, the last three or four inches of the 
ends bent outward, welded together, and inserted into the 
handle, as in a hoe or rake. The net is of bobbinet, with a 
mesh about like that of mosquito-netting, or finer. It is cut about 
four or five inches larger than the ring all around and gathered 
up to form a shallow bag without seams. This bag is edged 
with a band of strong cloth slightly larger than the ring and 
then sewed by this edge to the ring with good fine twine. 
The nymphs sprawling on the bottom are secured by vig- 
orous movements of the net close to the bottom, the currents 
produced sweeping them into the net. The burrowers are taken 
by scraping the surface layer of the bottom into the net or into 
a sieve, and then sifting or washing out the mud or sand, thus 
leaving only the nymphs and coarser rubbish. In deep-water 
collecting a dredge must be used. The swamp-inhabiting 
nymphs are easiest secured in the early morning as they come 
up for transformation. A pair of rubber boots is often very 
useful. 
The smaller imagos are easily taken, but the larger ones 
will often stimulate the activity and alertness of the collector 
to a considerable degree. If the air net be of light, strong, clean 
material, like bolting cloth, not too fine-meshed, the possibili- 
ties of capture will be greatly increased. The best time to col- 
lect dragon-flies is on cool, cloudy, or windy days. On one 
memorable occasion on the shore of Cedar Lake, just after a 
light rain,a heavier storm impending, the dragon-flies were 
found resting on weeds among the trees on the sloping shore, 
so sluggish that they were picked up by hand in large numbers. 
Eggs of the families which oviposit free in the water are 
