THE SUBFAMILY LIBELLULIN^E. 307 



Genus 74. Orchithemis. 

 (Neuration, Plate LVI. fig. 2.) 

 Brauer, Sitz. Akad. Wiss. Wien, xlvii. p. 196 (1878). 



Frontal tubercle bifid ; eyes contiguous for a moderately long space ; abdomen 

 moderately broad, nearly as long as the hind wings, gradually tapering towards the 

 extremity, the base not remarkably thickened, segments 2 and 8 carinated : wings 

 rather long and narrow, pterostigma moderate ; fore wings with 13-14 antenodal and 8-9 

 postnodal nervures, the first two postnodals not continuous, cells of the postcostal area 

 simple, triangle rather small, free, followed by two rows of cells, only increasing near the 

 hind margin, subtriangular space consisting of from one to three cells, sectors of the 

 arculus stalked, one supratriangular nervure before the triangle, lower basal cell with 

 one cross nervure, nodal sector continuous, hardly curved at base, this and all the other 

 sectors running nearly straight almost to the hind margin, where they curve downwards 

 gradually, the subnodal sector slightly irregular, cells between the nodal and subnodal 

 sectors simple ; hind wings hardly broader than the fore wings, with 11-12 antenodal 

 and 8-10 postnodal nervures, the first two subnodals not continuous, triangle traversed, 

 followed by three and then two and more rows of cells, no supratriangular nervure, two 

 nervures in the lower basal cell, sectors of the triangle rather widely separated at their 

 origin : anal appendages of male slender, curved downwards, as long as the ninth 

 segment, the lower appendage nearly as long as the others ; appendages of the second 

 segment very conspicuous. 



Type Orchithemis pulcherrima, Brauer. 



Genus 75. Diplacodes, g. n. 

 Diplacina, p., Brauer, Verb, zool.-bot. Gres. Wien, xviii. p. 733 (1868) . 



Frontal tubercle truncated ; eyes contiguous ; abdomen slender, linear, hardly dilated 

 at the base, about as long as the hind wings, segments 2 and 3 carinated, segment 8 

 not perfoliate in female ; pterostigma rather long : fore wings with 7-9 antenodal and 

 5-7 postnodal nervures, the last antenodal and the first two or three postnodals not 

 continuous, cells of the subcostal area simple, triangle moderate, nearly always open 

 (when traversed, only by a continuation of the nervure dividing the first two cells), on a 

 level with that of the hind wings, and followed by two rows of cells, no supratriangular 

 nervure, subtriangular space consisting of from one to three cells, when divided it is 

 primarily by a curved nervure cutting oif the lower angle, sectors of the arculus stalked, 

 more or less gradually curved, lower basal cell with one cross nervure, nodal sector 

 undulating at the base, subnodal sector very slightly irregular towards the extremity, 

 the intermediate cells only bisected towards the hind margin; hind wings slightly 

 broader than the fore wings, with 5-7 antenodal and 5-7 postnodal nervures, the first 

 two postnodals not continuous, triangle free, followed by three rows of cells, no supra- 



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