DRAGONFLIES AND DAMSELFLIES IN PONDFISH CULTURE. 241 
bristles along the dorsal surface of the abdomen, between the réspiratory system and the lateral margin 
on either side. The antenne are relatively large; base white with a pale grayish distal band; first 
joint white through the center, pale grayish at either end; second joint with proximal three-fifths dark 
and distal two-fifths white; third 
joint dark, tipped with white. 
These nymphs did not ascend 
to the surface of the water, like 
those of luctuosa, but stayed 
down near the bottom of the 
tumbler. 
The Mask.—Mentum twice 
as wide as long; the distal bor- 
der two and a half times the 
proximal; the lateral margins 
curved; three sete on either 
side, near the lateral margin; 
three mental sete in a straight 
line; a slight lobed promi- Wis. 44 and 4s—Hybrid from male Libellula pulchella and female Libellula luctuosa; 
nence behind the center of the 44, mask of newly hatched hybrid nymph; 4s, newly hatched hybrid nymph. 
distal margin, without spines. 
Lateral lobes one-third longer than wide; two sete on the outer border near the base; two on each 
blade; raptorial seta considerably longer than the movable hook, the latter short and slender; distal 
margin with four teeth near the outer edge, the first two the longest. 
ERYTHEMIS SIMPLICICOLLIS. 
The first females were seen laying in pond 4D on July 12, 1917. Eggs laid July 13 hatched July 23. 
The Egg.—The egg of this species is an elongated ellipse, with rather pointed ends, and is a little 
more than twice as long as wide, the respective diameters being 0.60 mm. and 0.27 mm. ‘The neck 
has a base narrower than its height, divided at the tip; there is a small process on the posterior end 
of the egg; the yolk granules are minute. 
The Nymph.—This nymph has the most pigment of any of those examined, and is banded brown 
and yellowish white; the eyes are light orange yellow with comparatively large black spots; the sides 
of the head are brown shading into light yellow on the median line; each thorax segment is brown 
0.5 mm. 
46 
Figs. 46 to 48.—Development of Ervtkemis simplicicollis: 46, egg; 47, mask of newly hatched nymph; 48, newly hatched nymph, 
bordered with dark yellow along the lateral margins and light yellow in the center, thus leaving a clear 
yellow longitudinal streak through the center of the body; the ninth and tenth segments are yellow; 
the legs are dark proximally, with a white band across the distal ends of the coxez, femora, and tibiz. 
The central yellow line of the head passes over the forehead and down between the antennz onto the 
labrum. On the back of the head it is widened considerably and usually mins out into two rounded 
points on either side, with two small, brown spots, one on either side of the midline, at the level of the 
posterior points. ‘Through the thorax it is narrow, then widens again on the first three or four abdomen 
