10 
11 
12 
DRAGONFLIES OF NORTH AMERICA 
2. Females 
Dorsum of abdominal segments 3-6 mostly pale............... 2. 
Dorsum of abdominal segments 3-6 mostly black (4-6 in bipunctu- 
PACAAVOER 5 ocd wa lerrvsinin va ce oR eee ee Ee eee 15. 
Post basal stripes present on abdominal segments 3-6 and con- 
fluent’ with the apical black... : i. .:s.i.6 ia. S eee 3. 
Post basal stripes present on abdominal segments 3- or 4—6, but 
not usually confluent with the apical black................ 8. 
Dark ‘humeral stripe forked... <1: 50.52 0 See ee eee 4. 
Dark humeral stripe not forked. 2450. 2 Pe ee 5. 
Length’ of abdomen 26mm... 0 fe. oo ee eee hinei, p. 295 
Length of abdomen 20 mm... 22). violacea, p. 300 
Mesepisternal tubercle absent.................... tonto, p. 299 
Mesepisternal tubercle present... .... 0. Sein s 1 ss eee 6. 
Dark middorsal and humeral stripes reduced to a thin line or 
SIDBCTIE:. eM eas oes so a hi aff se nas a a as 
Dark middorsal and humeral stripes wide, nearly as wide as the 
pale antemumernl: .o6\. |. eee ke eee ee vivida, p. 301 
Thorax usually with a black line on either side of the middorsal 
carina, which is also black. Oklahoma.........intruda, p. 296 
Thorax with only the middorsal carina black, no black lines on 
either side of it. General........ moesta (inc. putrida,) p. 297 
Segments 8-9 of abdomen without black on dorsum (except on 9 
in someispecimens: of tivida) ....) . eee. i 9. 
Segments 8-9 of the abdomen pale, each with a long black stripe 
on each side of the dorsum, from base backward to a variable 
distance: WQ0te.. 5e leet > US IRS. Te eee 13. 
Two enormous pits on the anterior ends of the mesepisternum, 
one under each mesostigmal lamina............ rita, p. 298 
No such pit? present: fe 2... 1 Oe, OS eee 10. 
Antenodal cells in front wing three............ immunda, p. 296 
Antenodal'cellgamiront wing’4-5... fey. . 5 <i it. 
Black middorsal thoracic and humeral stripes and mesepisternal 
tubercles\presetite. ess... s+ des. Se i ee 12. 
Black middorsal thoracic and humeral stripes reduced to a mere 
line or absent, mesepisternal tubercles absent... .sedula, p. 298 
Middorsal carina abruptly ending in the mesostigmal plate. ... 
TE Oe eee it. ee en se. S emma, p. 294 
Middorsal carina widening out into a broad triangle in the meso- 
stigmal plate. . .crcrersceere reese er men vivida, p. 301 
