198 DRAGONFLIES OF NORTH AMERICA 
cast above and with a whitish clypeus. Two minute yellowish spots sometimes 
are apparent toward the apical margin of the dark labrum. Frons above, vertex 
and occiput metallic green. Thorax of the same color, shining underneath the 
hoary hairs, only the depths of the lateral sutures appearing blackish. Legs 
black. Wings hyaline with stigma and costa black. Abdomen blackish green, 
with only a streak of yellowish on the sides of segments 2 and 3 beneath. Ap- 
pendages black. 
This species frequents the boggy edges of cold upland lakes and 
ponds. It flies swiftly, a few feet above the water, with occasional 
haltings, ‘‘marking time” in the air. These haltings give the best 
opportunity for capture with a net. The flight is free and graceful, as 
the coloration is beautiful. Occasionally one will leave its accustomed 
beat along the shore and sweep out far away from the water and dis- 
appear among the trees. 
The nymph (Ndm. ’01, p. 503) lives sprawling amid the trash at the 
edges of the water, and climbs a little way up projecting roots or sticks 
to transform. June is the time of transformation. Adults fly through 
July. 
34. DorocorpuLIA Needham 
These are elegant little dragonflies with hairy thorax and smooth 
shiny bronzy green abdomen. The abdomen is constricted in the middle 
and notably widened toward the tip. These are bog loving species of 
our Northeastern States and Canada. 
The nymphs are similar to those of Cordulia except for the characters 
stated in the key. Only the nymph of D. lepida has been made known 
(Ndm. ’01, p. 505). 
KEY TO THE SPECIES 
Adults 
1 Abdomen with segments 7 to 10 spatulately widened.......... 
aNd aide eras sett Ait nce CRNA aie eee ra ce Cg ed libera, p. 198 
Abdomen with segments very moderately widened. .lepida, p. 199 
167. Dorocordulia libera Selys 
Selys ’71, p. 263: Mtk. Cat. p. 127: Howe 19, p. 54: Garm. ’27, p. 238. 
Length 42 mm. Expanse 64 mm. Me., N. Y., Wis. and Ind. 
A charming little bronzy green species, with spatulately dilated abdomen. 
Face greenish with yellowish clypeus. Sides of frons obscurely marked with yel- 
lowish, top of frons, vertex and occiput metallic green. Thorax green, darkened 
only in the depths of the lateral stutures, densely clothed with tawny hairs. 
Legs black. Wings hyaline, with a golden tinge at the extreme base, costa and 
