348 DRAGONFLIES OF NORTH AMERICA 
13 Dorsum of abdominal segment 10 entirely black............... 
si a ue: sh hel insbascovea aueepebaurausto ne USGA Ret gee nO ean we denticollis, p. 348 
Dorsum of abdominal segment 10 with blue spots. .gemina, p. 349 
14 Unknown or’no material availables2-2. pa eee 
345. Ischnura denticollis Burmeister 
Burm. ’39, p. 819: Mtk. Cat. p. 68: Kndy. 717, p. 500: Smn. ’27, p. 15. 
Syn: exstriata Calv. 
Length 28 mm. Expanse 30 mm. Calif., Ariz.. Nev. and Utah 
This small feeble western damselfly has the face of the male, including the 
mouth parts, the genae, the postgenae, and the anteclypeus; pale. Labrum pale 
with a black basal line. Postclypeus black. Pale transverse frontal band wide, 
reaching to, and including the basal segments of the antennae. The vertex, 
remainder of the frons and antennae black. Pale postocular spots very small and 
entirely surrounded by black. Prothorax entirely metallic black except for a 
transverse stripe on the anterior lobe, and the sides of the middle lobe, which 
are pale blue. Thorax greenish blue, the dorsum entirely black: this color ex- 
tends rearward along the sides to half way between the first and second lateral 
sutures. Third lateral suture narrowly black, this color widening above into a 
spot. Abdomen shining black, except as follows: sides of segments 1-3 and 
8-10 blue. The apex of 2 blue. A trifoliate pure blue spot on the apex of the 
dorsum 8-9. Sides of segments 4-7 yellow. Segments 3-7 with narrow, pale 
basal rings, interrupted middorsally. 
Female, usual adult coloration. Labrum greenish edged with black above. 
Anteclypeus, genae, vertical surface of the frons, and the base of the mandibles 
bluish-green. Postclypeus and vertex black. Postocular spots moderate, blue, 
and confluent with the pale color of the rear of the head. Prothorax bluish-green 
on the sides, the dorsum black, except the anterior lobe. Thorax blue with wide 
middorsal black stripe and antehumeral pale stripe. A very narrow humeral 
dark stripe and basal spots at the base of the second and third lateral sutures. 
The abdomen has the dorsum entirely black, or is colored as in the male. 
“The female of this species from the teneral to the senile color passes through 
several remarkable color stages, and it is dichromatic and possibly trichromatic 
in color.’’—Kennedy. 
The following account of its habits has been taken from Dr. Ken- 
nedy’s (’17) account of this species. 
This smallest of western dragonflies occurs throughout the warmer valleys 
of Calif., Nev., Ariz. and N.W. Mex..... This species is found commonly on 
the high central plateau of Mexico... . at an elevation of over 6000 feet. In 
Calif. and Nev. it is found from sea-level up to 4400 feet. It is in these states 
distinctly a spring stream form, though in southern Calif. it is found about almost 
any permanent sluggish water. 
The habits of this species are in general Ischnuran but indicate greater feeble- 
ness. Early in the morning it is found in the sedges and grasses bordering the 
