102 DRAGONFLIES OF NORTH AMERICA 
the water for its prey, plunging entirely beneath the surface. It immediately 
comes forth, spreads its wings, and flies away into the very top of one of the 
tallest trees along the river bank, there to enjoy its meal in quiet security. 
It very seldom alighted on the shore and proved difficult to capture, all the 
specimens having to be shot either while hovering over the water or while munch- 
ing their prey in the trees. 
It may be recognized when flying near at hand by the reddish-brown posterior 
end of the abdomen, which stands out in good contrast to the darker color of the 
rest of the body. In hovering over the water the abdomen is not elevated, but is 
held nearly horizontal. 
Subgenus GoMPHUS 
This, the typical group, contains species that are more slender 
than those of Gomphurus, having the clubbed segments of the abdomen 
narrower and their lateral margins less dilated. In our species, veins 
A, and A; are generally wide apart, at the base, with two rows of cells 
between. The posterior hamules of the male stand vertically or nearly 
so, and the subgenital plate of the female is normally short. 
The nymphs of this group are depressed, with abdomen wider than 
head and regularly tapering to a pointed rear end. Burrowing hooks 
are fairly well developed on fore and middle tibiae. There is a rather 
well developed end hook on the lateral labial lobe with 4 to 10 teeth 
before it, and the teeth, if unequal, diminishinsize proximally. Lowrudi- 
The Known Nymphs 
Med. Dorsal Relative lengths | Lat. 
Species Length lobe Teeth hooks Sa GR a |e Described by 
australis 30 | convex 8 | rion9 Ze |) AOL | Gs 6 | 7-9 | Ndm. & Hart ’01, p. 78 


2 teeth 2g? on 5-6 
borealis 30 | convex 8-9 0 8 | 10] 5 6 | 7-9 | Ndm. ’03, p. 265 
1 tooth 
cavillaris 30 | convex 10 | rion 5-9 one LOG: 5 | 7-9 | Brtn. ’28, p. 33 
descriptus | 29-32 | hardly | 7-10] r'on3-9 | 7] 10] 4 5 | 6-9 | Ndm. ’01, p. 454 
convex 
exilis 19-26 | convex 4-7 | low on 6-9 | 7 | 10 | 6 | 5.5 | 6-9 | Hag. ’85, p. 263 
1 tooth 
graslinellus 32 | hardly 9] 46,ron | 8/10] 5 5 | 6-9 | Hag. ’85, p. 2644 
convex 3 and 9 
lividus 30 | straight | 6-8 | humps on | 8 | 10 | 4 5 | 6or| Ndm. ’01, p. 455 
7-9 7-9 
minutus 30 | convex 8 0 8 | 10] 6 6 | 7-9 | Brtn. ’28, p. 32 
convex 
spicatus 28-31 | 1 or 0 7-9 | rion 9 Mo kay iat 5 | 7-9 | Hag. ’85, p. 2658 
teeth 

1 Rudimentary 
2 Middorsal groove 
3 Described also in Needham ’01. 
4 Described also in Needham and Hart '01. 
