150 JOURNAL OF ENTOMOLOGY AND ZOOLOGY 
Co., Oxford, May 21, 1904 (Brltton). New York, Herkimer Co., 
Trenton Falls, collected by Osten Sacken; Dolgeville, May 16, 
1914 (Alexander); Fulton Co., Northampton, May 28, 1914 
(Alexander) ; Tompkins Co., Ithaca, May 1-10, 1913, (Alexander 
and Lloyd). Pcunsyhama, Wyoming Co., North Mt., June 7, 
1898 (Johnson). Maryland, Plummer's Is., April 12, 1908 (Bar- 
ber) ; April 21, 1907 (McAtee); Jackson's Is., May 22, 1913 
(Shannon and Barber) ; Cabin John Bridge, May 16, 1909 (Knab). 
Virc/inia, Fairfax Co., May (Banks). IUi}wis, collected by Kenni- 
cott. 
The following supplementary notes on the swarming and mating 
were made at Northampton (Fish-house) on the Sacandaga River, 
Fulton Co., N. Y., at the boom of the International Paper Mills. 
May 27, 1914 — This afternoon across the river from our camp 
this species was exceedingly abundant. They were there in untold 
myriads and at every step arose in clouds from under foot or from 
the leaves of choke-cherry on which they rested. They sat on the 
leaves with the head directed away from the observer ready to take 
instant flight. A few were in copulation on the leaves, but from 
observations made it seems probable that mating begins in the air 
and the pair seek a support later. Toward twilight this insect may 
be found in great numbers in company with many kinds of caddice- 
flies and a few may-flies. Seven p. m. — Eriocera swarming in great 
numbers, from 50 to 200 in a swarm facing the gentle westerly 
breeze (downstream). One big swarm near the shore numbered at 
least 2000 individuals and covered a vertical height of at least 50 
feet, the base of the swarm being about 15 feet above the surface of 
the water. Coming back across the boom it was found that several 
of these great swarms had fused so that one almost continuous 
swarm of thousands of individuals was formed, extending from 
shore to shore of the river. A great number of specimens were 
secured by a few sweeps of the net. When danger approaches, the 
swarm either mounts into the air overhead or else retreats before 
the breeze, never going sideways or advancing. Out over the land 
in the small swarms, copulation was observed several times. The 
males in the swarm dart rapidly at the females and seize them al- 
