168 NEW YORK STATE MUSEUM 
the 16th was a revelation. Insects of five orders in astonishing 
numbers had transformed beneath it, and: were assembled under 
the ridge cord, waiting to be picked off. There were several square 
feet of Chironomidae in the top, and stone flies and crane flies 
and caddis flies and May flies were scattered all over the sides. 
We found the gathering of all these specimens no inconsiderable 
task. It required usually more than an hour’s diligent application 
for two of tis every time. And this, added to other matters we 
had in hand, left us no time for investigating the relations these 
insects bear toward each other in the stream bed before their 
transformation. This account, therefore, of the insect life of 
Beaver Meadow brook is to be considered as a mere preliminary 
statement, giving only such data as were obtained with the aid of 
this. tent trap. We believe that this trap will yield quantitative 
results within its proper field (winged insects with aquatic larvae) 
and that it is the first to be devised that is of any value for quanti- 
tative purposes. And we believe furthermore, that this collecting 
method is one of wider applicability. We think, for instance, that 
a water tent may be used for positive determination of the breed- 
ing grounds of various kinds of mosquitos, and of the relative 
numbers in which each kind is produced. 
The yield of the winged insects from this area six feet square of 
brook bottom is shown in the following table :1 
1] have recently made an improvement in the construction of the tent 
trap —one that greatly economizes the labor of taking out the catch. I 
make it now in pyramidal form with opaque sides supported on a solid 
frame, but with a hole at the top, over which I place a light bag of netting. © 
The insects crawl up into this bag, which being detachable, may be ex- 
changed in a moment for another, and with all its contents inserted into a 
large cyanide bottle. 
