INDIAN DRAGONFLIES. 507 



quadrangular, overlapping the lobe laterally ; internal tentaculse robust hooks 

 curving first backwards and then outwards. Lobe rather higher than the tenta- 

 culfe, narrow and strongly arched. 



Sexual organs of the female ; border of 8th segment not dilated ; 8th ventral 

 plate prolonged as a rather large, oval, \'Tilvar scale which projects almost at a 

 right angle from the body axis ; 9th ventral plate sHghtly carinated in the middle 

 line. 



Wings moderately broad, often differing in the two sexes, often coloured 

 wholly or in part and often showing an extensive formation of secondary reticu- 

 lation ; trigone in the forewmg 2 to 3 cells distal to the line of the trigone in the 

 hind ; sectors of the arc in forewing short, in the hind, a longer fusion ; arc 

 between the 1st and 2nd or at the 2nd antenodal nervure ; 8th nervure in the 

 hindwing at the anal angle of the trigone ; antenodal nervures numerous, in the 

 forewing llj to 36, the final incomplete, often a development of reticulation 

 at the outermost antenodal nervures ; base of trigone in the hindwmg at the 

 arc ; 4th nervure moderately convex in the middle ; normally 1 row of cells 

 between 5 and oa, but owing to a developmen-t of secondary reticulation, this 

 space is often filled with a close irregular network made up of several rows of 

 cells ; trigone in the forewing relatively short and broad, its relation to the 

 hypertrigone rather more than a right angle, traversed by 1 or 2 main nervures 

 and often filled \\-ith secondary nervures ; trigone in the hindwmg with a strongly 

 concave, distal border, traversed once but often filled with a network of secon- 

 dary reticulation as in the trigone of the forewing ; cubital nervures generally 

 multiple ; supplementary nervures to the bridge either absent or if present 

 numerous ; 8th nervure strongly curved ; discoidal field with 3 rows of cells or 

 filled with a close reticulation ; nearly parallel sided as far as the termen. Anal 

 field of hindwing broad, loop with long and broad apex, the external angle 

 obtuse, the midrib almost straight. The cells between the inner border of loop 

 and basal margin of the wing, only indistinctly arranged in rows of largish cells 

 which in one species are further divided up by secondary nervules, Membrane 

 moderately large. Stigma moderate to very long. 



The members of this genus show wide variation in their general facies and 

 often very marked variation in the individuals of any one species. 



In some species the sexual differences, especially in colouring are very pro- 

 nounced. Six species are taken within Indian limits. 



Key to Species. 



A. Numerous nervures traversing the space bounded 



in front and behind by the subcostal and 3rd 



nervures and laterally by the node and the 



proximal end of the bridge. 



i. Male ; wings dark golden brown With 

 reddish reticulation as far out as the 

 stigma, the outer border of this mark- 

 ing strongly indented N. fulvia. 



B. No nervures traversing the space bounded in 



front and behind by the subcostal and 3rd 

 nervures and laterally by the node and the 

 proximal end of the bridge. 



i. Male ; base of wings up to the node in the 



forewing and distal to the node in the 



hind, black, iridiscent violet, bordered 



outwardly by a broad, white, opal band. 



Female ; base of wmgs yellow as far as 



node, a faii'ly broad, irregular fascia 



traversing both wings at the node and 



the apices brown N. lullia tullia, 



21 



