52 DRAGONFLIES OF NORTH AMERICA 
Diagnostic Characters of the Subfamilies of Anisoptera 
Brace _ Bisector Lat. car. 
Name Eyes Tri- of veinto of anal abd. 
above angles' H.W. — stigma loop 
AESCHNIDAE 
Petalurinae well alike? farout present absent variable 
apart 
Gomphinae well alike? farout present absent absent 
apart 
Aeschninae meeting alike farout present absent present 
Cordulegast- 
erinae touch- alike farout absent absent absent 
ing? 
LIBELLULIDAE 
Macromiinae meeting different nearer absent absent present 
Corduliinae meeting different opposite absent present present 
Libellulinae meeting different opposite absent present present 
1 Of fore and hind wings. 
2 Or nearly so. 
3 In relation to arculus. 
‘ Lateral carinae on abdomen. 
Auricles.5 
present 
present 
present 
present 
present 
present 
absent 
5 On side of second abdominal segment of male; notching of inner margin 
of wings goes with presence of auricles. 
Diagnostic Characters of Dragonfly Nymphs 
Groups irs.j. ant.j. labium  m. lobe lat. set. 
Petalurinae 3-3-3 76 flat entire absent 
Gomphinae 2-2-3 4° flat entire absent 
Aeschninae 3-3-3 v7 flat cleft absent 
Cordulegasterinae 3-3-3 ae mask cleft present 
Libellulidae 3-3-3 7? mask entire present 
ovp. 2 
absent 
absent 
present 
present 
absent 
The successive columns show the number of tarsal joints on fore, middle and 
hind tarsi, and of antennal joints; the shape of the labium, whether flat or mask 
shaped, covering most of the face, and whether cleft at the apex of the median 
lobe or not; also, whether there is a rowof definite raptorial setae upon the upper 
edge of the lateral labial lobe; and finally, whether there is an ovipositor de- 
veloped underneath the apical abdominal segments of the female nymphs. 
6 Terminal joints broad. 
7 Terminal joints slender, setaceous. 
8 Except in Gynacantha. 
