IMJiAy DRAGON FLIES. 019 



Abdomen short, slim and slightly fusiform in the male, cylindricul in the 

 female. 



Genitals ; male; small tentacuhe with no distinct ontor branch ; superior 

 appendages slim and strongly curved. Female ; border of 8th segment not 

 diluted : 8th ventral plate proh)nged in a somewhat projecting vulvar scale: 

 ventral plate of 9th segment drawn out into a long, tongue-like process 

 which overlaps a small 10th segment, tho latter furnished with long, fine 

 bristles. 



Wings small to moderately broad, nearly always partly coloured ; reti- 

 culation moderately open; trigone in the fore-wing with a nearly, uniformly 

 broken or bent costal side ; trigone in fore-wing in line with the trigone of 

 tho hind ; arc between antenodal nervures 1-2 ; sectors of arc stalked for 

 a long distance ; 8th and 9th nervures joined at the posterior angle of the 

 trigone in the hind- wing or occasionally separated for but a short distance; 

 7-9 antenodal nervures, the tinal one complete ; trigone in the hindvving 

 distal to the arc : 4th nervure with but a single, flat curve ; 1 row of cells 

 between o and 5a ; oa only poorly developed ; cubital nervures in fore-wing 

 varying, the distal one corresponding to the costal side of subtrigono which 

 is not regularly formed ; 2 to o cubital nervures in the hind-wing ; all 

 trigones entire ; hypertrigones usually traversed ; 1 row of cells in discoidal 

 field of fore-wing : 8th nervure in fore -wing nearly straight, the discoidal 

 field nearly parallel and a single row of cells nearly up to thetermen where 

 the field is a little dilated ; no supi,lementary nervures to bridge ; variable 

 loop, small, closed, seldom of more than 4 cells. 

 Stigma medium. Membrane nearly obsolete. 



o 



Key to Specik?. 



i. Base of wings a deep yellow colour, in the fore 

 up to trigone, in the hind up to node. 

 Brown colouration of apices if present, only 



poorly so and diffuse. 

 2-0 cubital nervures in the hindvving . . . .T. platyptem. 



ii. Base of wings hyaline. 



Brown colouration of apices well-marked and 



sharply limited. 

 2 cubital nervures in the hind-wing . . . . 7'. yerOunjii. 



1. Tetrathemis platyptera, Selys. 



r. flava, KriKjer. 



T. pulchra, Lnidlaic. Proc. Zoo. Soc, Land., 1902, I, p. 71, tab. i't.fifj. 3. 



Expanse 4o mm. Length 24 mm. 



Head, thorax and abdomen a dark yellow colour. 



Wings ; hind-wing rather short, the base bearing a constant bright yellow 

 suffusion extending from the base to the node or a little beyond it ; in the 

 fore-wing this suffusion reaches only to the trigone and has a somewhat 

 diffuse outer border. Bej^ond the node, the wing hyaline with, in some 

 specimens, a brown marking of the posterior part of the apex. 



Antenodal nervures in the fore-wing 9, in the hind 7 ; cubital nervures in 

 the fore-wing 1-2, in the hind 3. Superior appendages short, cylindrical, 

 pointed and in the female somewhat remote. 



Genitals : female : vulvar scale reaching up to the 9th abdominal seg- 

 ment, not projecting, terminating in a small, sharply curved arch. 9th 

 ventral plate prolonged in a small, elliptical tongue, placed somewhat 

 below and behind, overlapping the 10th segment which latter is furnished 

 with set£e. Stigma 2 mm. 



Hab. Bengal, Malacca. 



