Subfamily MacromiInaE 
The Belted Skimmers 
These are very large, strong flying, clear winged dragonflies, with 
robust bodies and long legs. In the hind wing the triangle is remote 
from the arculus (though nearer it than in the fore wing); the anal 
loop is never foot-shaped, but is short and compact, lacking a bisector. 
The distinctive feature of their coloration is a conspicuous band of 
yellow encircling the synthorax at the middle sutures, showing as a 
single oblique, middle yellow stripe upon the sides. 
These dragonflies are the monarchs of the upper air. They fly high 
and forage widely and are exceedingly difficult to capture. They go 
volplaning about the shores of lakes and large ponds and the more 
quiet places in the large streams. 
The nymphs are short and flat with widely sprawling legs. The eyes 
are very prominently elevated on the superolateral angles of the head, 
and between them is a conspicuous frontal horn. There is a row of 
strong, cultriform mid dorsal hooks running length-wise of the abdomen. 
These nymphs are not found in the weed beds, but on the bare areas 
of the bottom, amid the silt which spreads over them. 
The group is a small one, including in our limits but 2 genera, which 
may be distinguished as follows: 
KEY TO THE GENERA 
Adults 
1 Dorsal surface of the head with the occiput larger than the vertex; 
subtriangle of the fore wings usually divided by a cross vein; 
4 to 6 cross veins in the space above the bridge............ 
Beh aodavabecs Syn L2te Pee Dee a ee ee ee ee Didymops, p. 169 
Dorsal surface of the head with the occiput much smaller than the ~ 
vertex; subtriangle of the fore wings generally open; 2 or 3 cross 
veins in the space above the bridge......... Macromia, p. 164 
Nymphs 
1 Head hardly as wide across the eyes as across the bulging hind 
angles; lateral spines not incurved, those of the ninth abdominal 
segment hardly surpassed by the tips of the appendages; dorsum 
of the tenth abdominal segment with no trace of a dorsal hook 
ee ee eee em ee Didymops, p. 169 
Head widest across the eyes; spines of the ninth abdominal seg- 
ment shorter, not nearly reaching the level of the apices of the 
appendages; dorsum of the tenth segment with a very rudi- 
mentary dorsal Halk 3 ol. os oe ee oe Macromia, p. 165 
