356 DRAGONFLIES OF NORTH AMERICA 
third lateral suture and a black basal spot on the second lateral suture. Dorsum 
of the thorax entirely black, the pale antehumeral stripe being represented by 
two widely separated blue spots on the upper and lower end of each mesinfrae- 
pisternum. Dorsum of abdominal segments 1—7 metallic black. Segments 8-9 
blue, each with a rectangular black spot at the basal end of each, joined across 
the dorsum by a fine black basal line; preapical teeth also black. Segment 10 
mainly black above, the bifid process being conspicuous. The inferior abdominal 
appendages are deeply bifid. 
Female. The coloration in the female is very variable ranging between the 
light phase, Heterochromatic, where the extent of the black on the head and 
thorax has been reduced to a minimum, i.e., the postclypeus is entirely yellow, 
the postocular spots are large and joined, the dark middorsal and humeral 
thoracic stripes are mere lines and the legs are entirely pale; to the dark phase, 
homochromatic, where head and thorax are colored as in the male. The extent 
of pale coloration of the abdomen is less variable and resembles the male, except 
that the dorsum of segment 9, to a greater or less extent, inferiorly, is always 
black. On the hind margin of the prothorax there is a medium truncate tooth- 
like process with a pencil of erect hairs on either side. The females of cervula 
do not possess the ventral spine on the apical margin of segment 8. 
Dr. Kennedy (717) gives the following interesting account of this 
species as observed by him in Washington and Oregon. 
While occurring from early spring till heavy frostsin autumn, Jschnura cervula 
reaches its greatest abundance during the months of May and June. About 
running water it is scarce, in such places choosing the more stagnant spring 
laterals and side ponds. As with the other species of this genus, it is seldom 
found over the water or on land far from the moist banks of a pond or stream. 
It emerges in the day time usually between 9 and 11 o’clock in the morning, 
when it can sometimes be found emerging in swarms. At such times the nymphs 
can be seen swarming to the bank with a tadpole-like wriggling motion. They 
usually wait about 15 minutes after crawling from the water until they dry and 
the back splits. A half hour later they are on the wing. This species has, 
especially during imaginal life, the Lestes habit of hanging among aquatic 
vegetation and dodging among the reed stems to avoid capture. 
Copulation takes place with the couple moving about among the vegetation 
or at rest on some leaf, and lasts for many minutes. 
In oviposition, the female usually unaccompanied by the male, deposits her 
eggs in any vegetable matter under the surface of the water which is soft enough 
to be pierced by her ovipositor, usually the stems of aquatic plants, but some- 
times she will alight on the surface of a floating mass of filamentous algae and 
oviposit in the tangle of filaments. Usually the abdomen is bent U-shaped and 
the wings are loosely folded as in copulation, but occasionally she assumes the 
poses of perparva, with the wings tightly folded. 
359. Ischnura damula Calvert 
Calv. ’02, p. 126: Mtk. Cat. p. 68. 
Length 27-30 mm. Expanse 32-34 mm. N. Mex. and Colo. 
This species of Ischnura is similar to cervula in coloration. It differs mainly 
in the structure of the superior and inferior abdominal appendages and the dorsal 
