230 DRAGONFLIES OF NORTH AMERICA 
This is a most familiar skimmer. It divides its time between hovering 
over the water surface and perching on shore. The males are much in 
evidence. They rest with head low and tail elevated, and move the 
wings forward and downward into a drooping position by a succession 
of jerks. When old and pruinose they seem to prefer whitish perches, 
and will sometimes settle upon the rim of a collector’s white net or 
on his shirt sleeve or straw hat. They search ordinarily for the females 
and fly after them with great swiftness when discovered. 
The females slip in and out of sheltered places along shore, finding 
with difficulty a little freedom from molestation while laying their eggs. 
They hover low over the water, marking time, dipping down to the 
surface many times in nearly the same place, liberating 25 to 50 eggs 
at each descent. 
208. Plathemis subornata Hagen 
Hag. ’61, p. 149: Mtk. Cat. p. 142: Ris ’10, p. 263: Ndm. ’23, p. 130: Smn. 
726, p. 35. 
Length 45 mm. Expanse 70 mm. Kans. and Utah to Tex. and Calif. 
Face obscure brownish. Labrum, vertex, and cross stripe through ocelli, 
black. Thorax brownish with pale pubescence; the dark sides bear yellowish 
oblique stripes that are composed each of rows of 2 or 8 yellowish spots. Legs 
black. Wings as shown in accompanying figure; entire area before broad brown 
cross bands becoming pruinose around basal spots; stigma black. Abdomen 
blackish with lateral yellowish spots both above and below on swollen basal 
segments. These pale spots narrow and disappear to rearward. Apical segments 
and appendages black. 
45. Cannacria Kirby 
Slender and elongate dragonflies with abdomen laterally compressed 
on the three basal segments, scarcely widened as seen from above. 
Legs slender, hind femora spineless and thinly fringed with soft white 
hairs. Venation as indicated in key to the genera. Radial and median 
planate unusually well defined at outer end where strongly attached to 
veins; the upper of the 2 rows of subtended cells twice the width of the 
lower. 
Includes one South American species and the one described below. 
Habits and nymph unknown. 
209. Cannacria gravida Calvert 
Calv. ’90. p. 35: Mtk. Cat. p. 170 (as Brachymesia): Ris '12, p. 735. 
Length 50 mm. Expanse 82 mm. Md. to Fla. and Tex. 
A slender brownish species having usually a brownish spot on the middle 
of the wing. Face black and white. Labrum and frons black; sides of postclypeus 
white; intervening area variable, more or less spread over with brownish. Vertex 
