ef 
able that Walsh’s statements were based on insufficient data. 
The imagos usually keep near their nymphal home. The 
Zygoptera both fly and alight low, usually over water; the 
stronger E'schnide fly high and scatter more; while the other 
imagos are diversified in these respects, many species being 
taken both along streams and along borders of roads and fields 
at some distance from water. 
All dragon-flies are most active in hot, quiet, sunshiny 
weather. They cease flying by sunset, except a few of the 
Zé schnide, which may be seen in hot pursuit of small Diptera 
during the evening twilight. 
The history of the order as a whole in the vicinity of 
Havana, while under our observation, is interesting but some- 
what puzzling. In 1894 there was a great abundance of indi- 
viduals, in all stages. In 1895 the season’s collecting opened up 
well. Extremely low water prevailed, however, and in June the 
shallow waters became greatly heated by the sun, their recorded 
temperatures reaching as high as 96° Fahr. On one occasion, 
when the heat of the water was especially noticeable, a num- 
ber of dead nymphs were found floating about, along the west 
shore of Quiver Lake. Not many nymphs were seen in the usual 
situations at the close of this season, and from that time on 
through 1896, they were reduced to insignificant numbers. The 
low water of 1895, however, encouraged the development of spe- 
cies liking swampy situatious, and there was consequently in * 
1896 an excessive development of Pachydiplax longipennis and 
species of Sympetrum. A slight rise took place in the spring of 
1896 and the river became very foul. At the close of the year the 
drouth was broken, with a more extensive rise of the river, and 
the season of 1897 showed am increase in the number of nymphs. 
The winter and spring following brought much high water in 
the river, but the nymphs did not greatly increase in numbers. 
Kellicott has noted (97a ; 97, p. 69) that im Ohio the warm 
rainy weather of April, 1896, following the drouth of 1594-95, 
caused emergence earlier than usual, and the number appear- 
ing did not seem noticeably reduced by the drouth. 
