ENALLAGMA 329 
stripe .56-.63 mm., of pale antehumeral stripe .28—.42 mm., of the dark humerai 
stripe .28-.35 mm. Black on the dorsum of abdominal segment 9 of almost 
uniform width from base to apex. 
320. Enallagma sulcatum Williamson 
Wmsen. ’22, p. 114. 
Length 32-35 mm. Expanse 36-42 mm. Fla. 
Male. Color, orange, blue and black. Face orange. Postclypeus entirely 
shining black or with superimposed pale areas making it almost entirely orange 
in some specimens. Pale transverse frontal band not reaching the pale area an 
terior to the median ocellus. Antennae with the base and the first segment, at 
least, orange, remainder black. Vertex black except for a small pale spot anterior 
to each ocellus. Postocular spots linear and joined together by way of the pale 
postocellar stripe, or narrowly separated from it, never joined with the pale 
color of the rear of the head. Anterior and posterior lobes of the prothorax largely 
orange. Middle lobe black except for the sides and two lateral spots of orange. 
no median orange spot on the dorsum. Thorax with the pale antehumeral stripe 
narrower than the black humeral. Width of the black mid-dorsal stripe .87 mm., 
of the pale antehumeral stripe .26 mm., of the black humeral about .55 mm. 
Third lateral suture covered with a black stripe for about the upper five-sixths of 
its length. A short black spot on the caudal end of the second lateral suture. 
Abdomen with the dorsum of segments 1-8 and 10 entirely metallic black, except 
for narrow interrupted basal rings on segments 3-6. Segment 9 entirely blue. 
Superior appendages not quite as long as 10. 
Mesostigmal plate largely black, in the female, with a pale stripe, the pos- 
terior and inferior black portion grooved. Width of the black mid-dorsal thoracic 
stripe .78 mm., of the paie antehumeral stripe .27 mm., of the dark humeral 
about .6 mm. Black stripe on the second lateral suture on slightly less than the 
upper five-sixths of its length, continued as a thread of black to the inferior end 
of the suture. Black on the dorsum of abdominal segments 1-9, that on 9 not 
reaching the apex. Segment 10 pale. 
321. Enallagma signatum Hagen 
Hag. ’61, p. 84: Mtk. Cat. p. 61: Garm. 17, p. 553: Calv. 719, p. 337: Garm. ’27, 
p. 62. 
Syn: dentiferum Walsh 
Length 33 mm. Expanse 38 mm. U. S. east of Miss. R. 
A large black and orange damselfly occurring quite commonly, at times, 
about floating vegetation. Male. Face pale. Postclypeus usually entirely black, 
sometimes with margins and median spots or streaks of orange. Pale transverse 
frontal band not reaching the median ocellus. Base and the first segment of the 
antennae pale. Vertex black except for a small pale spot anterior to each ocellus. 
Pale postocular spots linear and connected with each other, by way of the pale 
postocellar stripe, but never connected with the pale color of the rear of the 
head. Anterior and posterior lobes of the prothorax pale. Middle lobe black 
with the sides, a median spot and two lateral spots, pale. Thorax with the pale 
antehumeral stripe as wide as, or wider than, the black humeral. Width of the 
