74 BuUct'Di Wisconsin Natural History Society. [Vol. 6, Nos. 1 — 2, 
rupted sub-apical black rings till 6, plainest toward the apical seg-- 
ments; 7 mostly black, 8 — 10 black with narrow red rings and some- 
times a mid -dorsal red stripe. 
Female. — Thorax brown. A]jical segments of abdomen brown or 
black with the mid-dorsal stripe more distinct. 
Life Zone : Transition and Upper Austral. 
Wisconsin : Waukesha Co., June 15, 1902 ; Milwaukee Co., June 
22— July 6, 1902, June 14, 1903. 
Time and Habitat — May to July in grasses of lakes and river- 
banks. 
ENALLAGMA Charpentier, Lib. ISTeur., p. 21, 1840; Needham, Proc. 
U. S. Nat. Mus., 26, p. 720, 1903 (Venation). 
Most of our brightly colored damsel-flies flitting about the 
lakes, ponds and rivers in the early summer months belong to this 
genus. They are prettily colored, some blue, green and black, 
especially on the alDdominal segments, others are mainl}^ orange 
and yellow, varied with black, or blue on some segments of the ab- 
domen. The considerable variation in color and extent of the 
markings make them quite difficult to determine. In the males, 
however, this difficulty is obviated by the sufficienlty characteris- 
tic abdominal appendages. But the females, because of the great 
similarity of the species, tax the student's ingenuity to the utmost, 
and even then, in cases like carunculatum and civile, there is no 
absolute certainty of specific values. Certainty in such cases can 
only be had when the female is caught with the male. The follow- 
ing table, based on colors, refers only to males. 
1. Dorsum of segment 2 of abdomen blue with an apical spot 
black 2 
Dorsum of segment 2 black 14 
2. Dorsum of segment 3 — 5 at least one third blue 3 
Dorsum of segment 3 — 5 mostly black 11 
3. Segment 5 more than half blue 4 
Segment 5 with blue and black about equal carunculatum 
4. Apical two thirds of 6 black 5 
Apical third of 6 black hageni 
5. Superior appendages simple, cylindrical 6 
Superior appendages bifid 8 
6. Inferiors longer than superiors 7 
Inferiors not longer than superiors, strongly upcurved durum 
7. Superiors with an apical recurved lobe annexum 
Superiors with an apical tubercle calverti 
8. Superiors with an introduced tubercle between the branches. . . 9 
Superiors without an introduced tubercle between the branches 10 
9. Branches of the superior appendages equal ebrium 
Branches unequal, the upper shorter than the lower .. .doubledayi 
10. Tubercle equal in size to the branches civile 
Tubercle reduced, much smaller than the branches anna 
11. Sides of segment 2 blue 12 
Sides of segment 2 with a black spot geminatum 
