SUBFAMILY GOMPHINAE 59 
egg laying are unattended by the males. They move slowly above the 
water, descending to strike the surface at irregular intervals, liberating 
a score or more of eggs at every stroke. In copulation the pairs seek 
the shelter of shore vegetation. Some of the larger forms hang up 
in the tree tops. 
The nymphs of this group are burrowers in bottom mud, sand and 
sediment. They are at once distinguishable by the wedge-shaped 
form of the head, the thick four-jointed antennae and the two-jointed 
front tarsi. The tips of the front tibiae are more or less flattened and 
hooked for burrowing. Their legs being scarcely opposable, they do 
not climb up slender stems at time of transformation, but lie flat 
upon the sand of the shore or sprawl over mats of grass or climb a 
little way up on broad rough surfaces, such as tree trunks. 
KEY TO THE GENERA 
Adults 
1 Fore wing, nodus beyond the middle of the wing and basal sub- 
costalicrossweingenerally present... |... 0. donors ee 2. 
Fore wing, nodus at the middle of the wing and basal subcostal 
ALToTSIe ier Cl fas cE Sek aa ered a eS 2 Ane eae COIN Ae ok I 5. 
De UO GREBE Ny s2 4 08 Be a os, De! hie 2) a's, ayers Satine pees 3. 
Aa DIG evap, 28 eM Mien: ve ates on lee a 4, 
3 Triangle short, outer side nearly straight, not at all sigmoid 
SOP nL SSR AE Ma So! tiene SS cree CY ae a Cyclophylla, p. 65 
Triangle long, outer side with sigmoid curvature.............. 
OE sg nay De aa tie Rede UREA RUS RY I. Ye Seno Si Gomphoides, p. 63 
4 Hind wing triangle with outer side nearly straight; trigonal 
Plamavesweak. «<< Suge ls aca) pk ee ee Aphylla, p. 64 
Hind wing triangle with outer side angulate; trigonal planate 
WellidewelOpeGes. <0. flees sad fee ees Progomphus, p. 62 
5 Triangles with a cross vein; anal loop of four cells Hagenius, p.65 
Triangles open; anal loop of fewer cells or wanting............. 6. 
6 Anal loop semicircular, of three cells...... Ophiogomphus, p. 67 
Anal loopindistiieh on waAnbIng .))..¢-..)..:<ccuuanet te copumeedneed 3 G 
7 Hind wing with anal crossing distant from second cubito-anal 
cross Vein. by less thanits own leneth, oo eee. * oo 8. 
Hind wing with anal crossing distant from second cubito-anal 
éross vein by more thanitsown length... .-.795 99. 0. .25.. 16: 
