322 DRAGONFLIES OF NORTH AMERICA 
28 Prothoracic dorsal pits situated anterior to the middle of the me- 
dian lobe. The middorsal and humeral black stripes broadly 
joined by a black bar across the mesostigmal plate.......... 
lela a oi Saar Deen a une shine Lats Ree THUN HAS Bo Me dues = pictum, p. 331 
Prothoracic dorsal pits situated at about mid-length of the median 
lobe. Middorsal and humeral black stripes narrowly joined by a 
black stripe on the suture of the mesostigmal plate.......... 
aha ty Subir EATS im: caic oad lee le nad ROAR UE mere mine ee concisum, p. 332 
N. B. The females of the following species have not been included in 
this key, either because they are, as yet, not known, or have 
been inadequately described: culicinorum, dubium, eiseni, 
laterale, minusculum, piscinarium and semicirculare. 
306. Enallagma divagans Selys 
Selys ’76, p. 52: Mtk. Cat. p. 58: Garm. ’17, p. 536 and ’27, p. 79. 
Length 29-33 mm. Expanse 40 mm. Mass. to Fla. to Ind., Mich. and IIl. 
Color dark blue and black. 
Male.—Face blue. Labrum with a black median spot, postclypeus black, 
antennae black. Anterior part of frons blue, remainder of frons and vertex black. 
Postocular spots subcuneiform and not connected. Prothorax black with spots 
of varying sizes, one on the anterior lobe, sometimes very large, two lateral ones 
on the middle lobe, two lateral ones and a median one on the hind lobe, all pale. 
Thorax with the middorsal and humeral dark stripe wide, antehumeral pale 
stripe narrower than either. A short black basal line on the second and third 
lateral sutures. Abdomen blue-bronze, black as follows: a basal spot on 1; 
entire dorsum of 2-7 and 10. 8—9 entirely blue except for an occasional minute 
isolated black spot on the sides. Superior appendages black, shorter than 10, and 
not bifid, but comma-shaped with a short rounded upper part followed by an 
incurved slender process. In some specimens the differentiation between the 
“head” and “‘tail’’ of the comma is so marked as to give the appendage a bifid 
appearance. 
The female is similar to the male except the abdomen. The 8th abdominal 
segment is black on the dorsum with pale blue lateral spots on the caudal margin. 
Segment 9 blue with two short dorso-lateral black stripes that fuse at the base 
of the meson. 10 blue. 
307. Enallagma hageni Walsh 
Walsh ’63, p. 234: Mtk. Cat. p. 60: Whed. ’14, p. 93: Garm. 717, p. 547 and ’27, 
p. 75. 
Length 30 mm. Expanse 38 mm. Me. and Pa. to N. Dak. 
This species is probably our most common northeastern Zygopteron, being 
rivaled in its range only by Ischnura verticalis for number of individuals. During 
the summer it is usually present about ponds in such quantities as to be taken 
by the netful rather than as individuals. Masses of floating vegetation are dotted 
