PERITHEMIS 205 
Our smallest skimmer. Face white with a black labrum and a big blackish 
median spot lying across the front-clypeal stuture. Vertex metallic blue. A 
broad black transverse stripe includes the middle ocellus. Thorax at first yellow, 
striped with black, later pruinose blue. Stripes on front of thorax very broad, 
covering most of area, leaving 2 oblique isolated yellow lines. On the sides the 
first stripe (2 and 3 fused) is broad and continuous, the 2 other stripes (4 and 5) 
are interrupted above and irregular, and tend to be confluent with each other 
at 2 points. Behind the last one there is an additional inferior brown streak. 
Legs black, Wings hyaline, sometimes broadly tinged with yellow at base, es- 
pecially in the 9. Stigma brown, whitish at ends. Abdomen black, broadly 
cross barred with yellow on the basal segments, becoming wholly pruinose blue 
with age. Appendage yellow. 
Weith (’01) was the first to work on the life history of this species. 
He says: 
Unlike most other Odonata, the imagos do not fly higher than a few feet 
above the ground, preferring to alight on the marsh grass and bask in the sun- 
shine, where numerous small Deptera suitable for food hover over the little 
stagnant pools. 
On June 22nd I found a number of females ovipositing in the shallow places 
where I had found the nymphs, in temporary water one to two inches in depth 
and very warm. The female dips her abdomen to the surface, after the manner 
of all Libellulines, but only about 3 or 4 times, then rests on the grass a few 
minutes and then repeats. 
37. PERITHEMIS Hagen 
Amber-wings 
Small dragonflies that lack the usual swelling on the basal abdominal 
segments and have the middle segments widest. The eyes are large, 
and for a distance confluent. Prothorax bilobed dorsally, the lobes 
fringed with long hairs. Thorax densely clothed with short brown hairs. 
Wings are short and broad with unique venation, the triangle of fore 
wing being as broad as long, and the bisector of the anal loop in the 
hind wing being almost straight. Sexes differently colored, wing of the 
female being very prettily marked with a pattern of brown. 
Though a number of names have been applied to the different color 
forms of this species, we are not able to define them and therefore treat 
them here as representing a single variable species. 
The nymph (Ndm. ’01, p. 513) of this genus is rather unique among 
our Libellulines in possessing a full series of flat, cultriform dorsal hooks 
the last being on segment 9. 
172. Perithemis domitia Drury 
Drury 1773: Mtk. Cat. p. 145. Whed. ’14, p. 101: Howe ’20, p. 75: Ris. ’10, 
p. 331: Garm. 27, p. 258. 
