JAPANESE DRAGONFLIES OF THE FAMILY CALOPTERYGIDAE. 105 
and to characterize them as follows. 
8. Mnais strigata Hagen. 
Mnais strigata Selys, Synop. Calop. p. 20 (1853). 
Mnais pruinosa (male) Selys, Synop. Calop. p. 20 (1853). 
Mnais costalis (male) Selys, Synop. Calop. add. II. p. 7 (1869). 
Mnais pruinosa race costalis, Selys, Ann. Soc. Ent. Belg. XXVII. p. 
129 (1883). 
^ 40-45mm. ^ 35-40mm. 
o' 35-38mm. ^ 35-38mm. 
^ 1.8-2mm. $ 1.5-2mm. 
Body metallic green or greenish 
Length of the abdomen 
Length of the hind wing 
Length of the pterostigma 
Male. Polymorphic in wing color, 
blue, dencely pruinosed in adult specimens, exept latenal sides of the thorax. 
The both sides of the labrum, a patch on the first joint of antenna, a small 
part on coxa and two streaks on the metepimeron dull yellow. Legs black. 
Upper anal appendages also black, blunt tipped, curved inwards with seven 
or eight spines of indefinite size along their outer margins. Wings vary 
according to forms as I am going to mention below, pteratigma long, in- 
variably red in color. 
a. iypica (Hagen) Oguma. (PI. 1. fig. 3). 
Wings hyaline, often faintly suffused with pale yellow, nervures dark 
brown. I take this species as the typical form, not only by its simplest 
color like females, but also being priorly described. 
ß. costalis Selys. (PI. 1. fig. 1-2). 
Wings hyaline, distal three fourths bright saffron with an opaque part 
of brick color along the costa, the nervures dark brown, but those imbedded 
in the colored part likewise saffron. In the most of specimens the opaque 
part not extended to the pterostigma distally and to M 2 , at most, posteriorly, 
but I have a single specimen in which the opaque part greatly elongated- 
reaching up to pterostigma in one direction, while surpassing A x in other 
