338 DRAGONFLIES OF NORTH AMERICA 
336. Enallagma anna Williamson 
Wmen. ’00, p. 455: Mtk. Cat. p. 54: Kndy. ’17, p. 616. 
Length 32 mm. Expanse 45 mm. Wyo., Ariz., Utah 
This very pretty blue and black western damselfly is one of the few species 
in which the females submerge in ovipositing, unaccompanied by the male, 
although the male is present with her as usual until submergence takes place. 
The head of the male is blue above, yellowish below, vertex and frons black 
above. The first joint of the antennae is blue, the remainder black. Postocular 
spots connected with the postocellar pale stripe. Prothorax black, blue as follows: 
a transverse stripe covering the anterior half of the first lobe, a spot on either side 
and the sides of the middle lobe, and the posterior border of the hind lobe, which 
is entire and flattened above. Thorax with the following black: a middorsal 
stripe, a humeral stripe, wider below, and a line on the basal third or fourth of 
the third lateral suture. Abdomen blue with the following black: a basal spot 
on 1; an apical spot and narrow ring on 2; apical half or third of 3; apical half 
to three-fourths of 4; apical three-fifths or two-thirds of 5, apical two-thirds or 
three-fourths of 6; nearly all of 7; none of 8-9; all of 10. Superior appendages in 
profile view, about as long as 10, bifid, inferior arm shorter than the superior, 
a small pale tubercle usually present between them. 
The female is similar to the male except the posterior border of the prothorax 
has a low median elevation with a lower one on either side. Abdomen with the 
dorsum of 2—10 black, 10 very narrowly, sides and basal rings of abdomen yellow- 
ish or greenish. The wings of the female, as in all Enallagma, are slightly longer 
than those of the male. 
337. Enallagma eiseni Calvert 
Calv. 95, p. 486: Mtk. Cat. p. 59. 
Length 32 mm. Expanse 40 mm. B. Calif. 
Colors, blue and metallic black. The black as follows: a small median dot at 
the base of the labrum; the postclypeus; the antennae, except the first and the 
front of the second joint; the vertex; a narrow transverse band behind the blue 
postocular spots, these spots being cuneiform and connected with each other. 
Dorsum of prothorax black except the anterior and posterior borders, and a 
median twin spot, and lateral spots, and the sides of the middle lobe, which are 
pale. Thorax with the middorsal stripe black, but with the middorsal carina 
blue. Black humeral stripe, and a short black stripe at the base of the third 
lateral suture sometimes prolonged into a fine line, the only other black on the 
thorax. Abdomen blue, black as follows: a dorsal spot on the base of 1; on 2 
varying from a rather narrow middorsal band reaching from the base to the 
apex, narrowed at the middle of the segment, with an angular dialiation before 
the apex, to a round apical spot connected by an apical tail with the apex of 
the segment; 3 with lanceolate middorsal spot, pointed posteriorly, on the basal 
half, and a broader spot or band on the apical fourth; 4-6 similar to 3; 7 almost 
entirely; 8-10 blue, 8 with a minute middorsal, basal point, 10 with a narrow 
median stripe, black. Superior appendages longer than 10, bifid, the upper arm 
long, the lower arm appearing as an inferior basal triangle with the point directed 
ventrally. 
The female is unknown. 
