152 JOURNAL OF ENTOMOLOGY AND ZOOLOGY 
male retired to a support although the species was never observed 
to swarm during the hours of sunlight. 
The number of individuals participating in these swarms was 
again very astonishing, many of the swarms numbering thousands 
of individuals. The motions in the swarms were very rapid, almost 
like bees, and the sound produced was a very low pitch, much lower 
than that of Ciilex. 
May 29, 1914 — A rather strong southerly breeze blowing. At 
6:35 p. m. small swarms of from 25 to 30 individuals had gathered. 
At this time the sun was still up but low in the west. These swarms 
were enlarged rapidly. At 6 :45 one big swarm was formed near 
the east bank, this being nearest the point where the insects spend 
their days and so they swarmed there first. One pairing of three 
individuals came down as described above and when about a foot 
above a board in the water, the male in copulation dropped the other 
two. These rested for a moment and then the male attempted to 
engage the female in copulation. She resisted but finally he man- 
aged to seize her with his forceps. Then he attempted to fly away 
but she seized hold of the board with all her feet and he was un- 
able to fly away. This seems to prove that the normal place for 
copulation is in the air. 
Enemies: Dragon-flies, Hclocorditlia uhleri Selys, feed upon the 
Eriocera swarms during sunlight. They do their capturing by dart- 
ing back and forth through the masses of individuals. 
Oviposition: Many Eriocera were noted engaged in dipping 
down to the water as though engaged in the laying of eggs. Only 
a few individuals allowed themselves to be taken and all of those 
secured proved to be males. Why males should go through these 
actions is uncertain to me, but I have observed it many times in 
several different species. I think that the female lays her eggs in 
the water although no specimens were taken while egg-laying. 
PENTHOPTERA Schiner 
This interesting genus includes but six described species of which 
P. chirothecala Scop., P. dniicoidcs Scop., P. schmtsci Kuntze and 
P. grisca Riedel are Palaearctic, P. albilarsis O. S. is Nearctic and 
