230 NEW YORK STATE MUSEUM 
and remains stopped till the pools are refilled in late autumn, ~ 
and the stems and leaves, now dead, fall into the water. I have 
gathered the eggs in the middle of July and again in the middle 
of October and found them at apparently the same stage of de- 
velopment. Eggs placed at the latter date in a bowl of water 
in my laboratory hatched within a week. I did not try hatching 
any of them earlier. : 
Exposed as they are above the water, these eggs are subject to 
parasites, which destroy often a large proportion of them. 
From a handful of bur reed leaves well studded with Lestes eggs, 
Fig.6 Theegg of Lestes uncata : 
I once bred large numbers of the following parasites, the two 
last named being hyperparasites on the third named in the list. 
Brachista pallida Ashm. 
Centrobia odonatae Ashm. | 
Polynema needhami Ashm. | 
Tetrastichus polynemae Ashm. 
Hyperteles polynemae Ashm. . 
The nymphs live among submerged plant stems. Their ex- 
tremely slender legs, long swaying bodies, and leaflike gill | 
plates, together with a sober color pattern of greens and browns, 
render them very inconspicuous when in their native haunts. 
In aquariums they are rather shy, and do not feed under observa- 
tion so readily as do many other genera. I have observed them 
eating some of the larger entomostraca and smaller dipterous 
larvae (Corethra and Chironomus). 
Since the nine species occurring in or regional in New York 
State have all been described several times in recent and avail- _ 
able papers, and since the females are well nigh indistinguish- 
able, and determinations must at present be based on the males 
and chiefly on the form of the terminal abdominal appendages 
of the males, I have not thought it worth while to give descrip- 
