306 DRAGONFLIES OF NORTH AMERICA 
Transformation is apparently at its height about the latter end of 
August. It occurs always within a few inches of the surface of the water. 
The color changes that this species undergoes after transformation are 
very striking. It emerges from the nymph skin pale yellow and be- 
comes more yellow before it turns red. The bronzy green-black stripes 
upon the thorax and across the top of the head are at first pale brown 
and then deep brown and acquire their metallic luster only at full 
maturity. 
68. NEHALENNIA Selys 
These are very delicate little bronzy green damselflies the entire 
dorsum of head and body is more or less completely rich bronzy green. 
The face is pale, cross lined with black. The legs are short, pale, with 
black stripings and black spines. Wings are hyaline with pale stigma 
covering a single cell and with narrow quadrangle. The abdomen is 
very slender widening a little toward both ends. 
The nymphs (Ndm. ’03, p. 249) are slender, climbing forms that 
inhabit dense beds of submerged vegetation. They are greenish in color 
with faint brownish rings on legs and with spots on the gill margins. 
Our species of this Holarctic genus are distinguishable as follows: 
KEY TO THE SPECIES* 
Adults 
1. Males 
1 Superior appendages longer than the inferiors. Dorsum of abdo- 
minal segments 8-9 dark metallic blue, each with a narrow 
transverse pale line at base and apex, sides pale blue; 10 pale 
blue with a little black at the base middorsally............ 
eT IBRe IK! Set ne itll Unt PmN Me Viele Sta, nds Seat pallidula, p. 307 
Superior appendages equal to or shorter than the inferiors...... pak 
2 Abdominal segment 8 blue, with a transverse dorsal basal black or 
metallic green line or spot, 9-10 entirely pale blue. Superior 
appendages nearly as long but not as high as the inferiors seen 
in, profilesviews sce Ce ee oe gracilis, p. 307 
Abdominal segment 8 with a broad dark dorsal band reaching 
nearly to the apical margin; 9-10 blue with dark markings. .3. 
* Prepared by C. F. Byers. 
