On the evening of August 13th, 1881, I observed them between the hours of 5 and 7 o'clock. The air for miles around seemed literally alive with these dragon-flies, from a foot above ground to as far as the eye could reach, all flying in the same direction, a south-westerly course, and the few that would occasionally cross the track of the majority could all the more easily be noticed from the very regular and swift course they generally pursued; but even these few stray ones would soon fall in with the rest again. Very few were seen alighting, and all carefully avoided any movable obstacles.

The next day very few were seen on the prairies, and these mostly of another species very abundant in this country, Anax junius (Drury), which were probably at home previously, and in a few days I could see none others but the latter. A few newspapers, and also a few correspondents from twelve to fifteen miles east and west of here, had observed and mentioned their flight.