SOMATOCHLORA 187 
147. Somatochlora ensigera Martin 
Mrin. ‘07, p. 298: Wmsn. ’07, p. 5: 712, p. 1538: Walk. ’25, p. 86. 
Length 50 mm, Expanse 72 mm. Colo., Mont. 
Syn: charadriae Wmsn. 
Labrum orange with a black border and a black median spot. Postclypeus 
ochraceous. Frons metallic blue in middle, surrounded at side and in front with 
orange brown. Occiput red brown. Thorax red brown deepening to blue black 
above. Side stripes well defined, the first broad and parallel sided, the second 
shorter and convex behind. Legs black, paler basally. Wings hyaline; stigma 
brownish. Abdomen greenish black, spotted conspicuously with yellow on the 
three basal segments; middorsal spot on 1, large lateral spots on 2, 2 basal tri- 
angular spots on 3, one laterodorsal the other lateroventral. 
Williamson ’07 quotes concerning this species: 
I took it at an altitude of about 8000 feet, July 31, 1898, in Bear Creek 
Canon, Jefferson Co., Colo. At the place I took it there were 2, but on account 
of the wariness and the almost inaccessible character of its haunts (on willows 
overhanging the swift and breakneck dashing Bear Creek), I was unable to 
secure the other specimen. The one captured was taken with difficulty, as it 
kept just out of the reach of the net. It appeared a weak flier however, and my 
opportunity came when an unusually strong gust of wind blew it towards me. 
148. Somatochlora tenebrosa Say 
Say ’39, p. 18: Mtk. Cat. p. 182: Wlsn. 712, p. 194: Walk. ’25, p. 100: Garm. 27, 
p. 227. 
Length 48 mm. Expanse 76 mm. N.H., N. Y. and N. J. to Ill. and Ky. 
A handsome species with brilliant thoracic coloration. Occiput brown. 
Face ochraceous; top of frons and vertex metallic; labrum yellow with median 
black spot and sometimes with a black border. Thorax brilliantly metallic 
bronze and green, the two lateral stripes pale yellow, the first dilated above, 
the second subovate and shorter. Legs black, femora paler externally. Wings 
hyaline with a faint basal tinge of amber; veins and stigma dark brown. Abdo- 
men blackish; segment 2 with large ventro-lateral yellow spots; accessory geni- 
talia pale; 3 pale basally with 2 pairs of lateral triangular spots. 
Walker (’25) says it is an inhabitant of the small forest streams, and 
that it seems to be partial to shady places. Other writers speak of it 
as being distinctly crepuscular and shade loving. Brimley ’03 reports 
it “flying over fields and open ground by the side of small streams and 
marshes—flies high and is hard to catch.”’? Wilson 712, says: 
Ten or a dozen specimens were patrolling back and forth just after sunset 
in one corner of an old pasture near a small brook at the foot of the mountains. 
They were strong and rapid fliers and extremely difficult to capture. They moved 
gracefully up and down and in and out, weaving together their paths of flight 
like the intricate mazes of an old fashioned dance. But never for an instant could 
they be caught off their guard. At the first attempt of the net they all retired 
