DRAGONFLIES AND DAMSELFLIES IN PONDFISH CULTURE. 245 
cylindrical, covered with short and straight spines or sete. All the leg joints, including the coxe, 
are sparsely armed with sete; and there is a row of sete also along the dorsal surface of the abdomen 
close to the lateral margin. The color is a uniform, creamy white, except the three dark bands on the 
antenne and a narrow band on each femur and tibia of the legs. 
The Mask.—Mentum triangular, one-half wider than long; distal margin twice the length of the proxi- 
mal; one mental seta on either side, one lateral seta at the base of each lobe, two marginal sete; a row of 
nine small spines just behind the distal margin. Lateral lobes twice as long as wide, with one marginal 
seta and two raptorial setae; movable hook long and stout; an accessory spine just outside the base of the 
distal raptorial seta. 
Nis 
(A 
|>==4 
Si 
K 
NS 
& Sas 
SS i 1 LEZ 
IIA | ESR, 
TI ns 
Y, A OR \y 
(y 
PSO 
rs 
Sh 
TTT 
pipe 453) 
Sania 
VA 
it 
SF 
ZA 
SS 
58 
Fics. <8 to 60.—Development of Enallagma hageni: 58, egg; 59, mask of newly hatched nymph; 60, newly hatched nymph. 
ENALLAGMA SIGNATUM. 
These eggs were obtained from pond-lily leaves on July 28, r917, and began to hatch 18 days later, 
the period of incubation being again unknown. 
The Eqg.—The eggs are considerably like those of E. hageni, but they were arranged very differ- 
ently in the tissues of the leaf. Those of hageni were inserted without any definite order anywhere 
in the leaf; these were arranged in a semicircle on the underside of the leaf around some convenient hole 
or close to the margin. The female evidently thrust her abdomen down through the hole or down over 
the edge of the leaf and, reaching as far as she could, inserted the eggs into the leaf. 
The Nymph.—The nymph is just 1 mm. long, exclusive of the caudal gills; head wider than long, 
the two diameters in the proportion of 7 to 5, the anterior and posterior margins both strongly convex; 
thorax shorter than the head and two-thirds as wide; abdomen the same width as the thorax and taper- 
ing gradually backward; caudal gills short and slender; legs also comparatively short and slender, 
the posterior pair not reaching the center of the caudal gills; claws short and stout. The antennez are 
long and stout; the eyes at the center of the lateral margins project strongly. There are no sete 
on the dorsal surface of the head, on the thorax, or on the coxe of the legs; there is a single seta on the 
center of each abdominal segment near the lateral margin on each side; and the setz on the legs and 
