THE SUBFAMILY LIBELLULIKE. 269 



of the arculus nearly continuous ; hind wings not much broader than the fore wings, 

 with 7-9 antenodal and 9-11 postnodal nervures, the first two or three postnodals not 

 continuous, triangle free, followed by two (rarely three) rows of cells : anal appendages 

 rather short. 



Type Tramea iphigenia, Hag. 



(Plate LII. fig. 3.) 



Frontal tubercle truncated ; eyes large, contiguous in front for rather a long space ; 

 abdomen slender, rather shorter than the hind wings, compressed, somewhat gibbous 

 at the base, segments 2 and 3 carinated, 4 imperfectly so, segment 8 not perfoliate in 

 female: wings rather broad, pterostigma short; fore wings with 7-9 antenodal ner- 

 vures, the last not continuous, and 5-8 postnodal nervures, the first two not continuous, 

 cells of the postnodal area simple, triangle rather narrow, placed considerably beyond 

 that of the hind wings, free, followed by two rows of cells, only increasing on the hind 

 margin, no supratriangular nervures, one cross nervure in the lower basal cell, subtri- 

 angular space consisting of one very large pentagonal cell, sectors of the arculus 

 stalked, nodal sector considerably waved at the base, subnodal sector and lower sector 

 of the arculus broken beyond the middle, intermediate cells between the nodal and 

 subnodal sectors only bisected on the hind margin ; hind wings much broader than the 

 fore wings, with 4-5 antenodal and 6-9 postnodal nervures, the first two or three post- 

 nodals not continuous, triangle free, its base on a level with the arculus, followed by 

 two rows of cells increasing, no supratriangular nervure, one cross nervure in the lower 

 basal cell, sectors of the triangle rising together, membranule very large : anal appen- 

 dages of the male slender, arched, as long as the ninth segment, those of the second 

 segment moderately developed. 



Type IAbellula simplex, Ramb. 



Genus 9. Rhyothemis. 

 (Plate LI. figs. 5, 6.) 



Hageu, Stett. eut. Zeit. xxviii. p. 232 (1867) ; Brauer, Verh. zool.-bot. Ges. Wien, xviii. pp. 364, 



714 (1868). 



Frontal tubercle moderately broad, more or less depressed in the middle when viewed 

 from the front ; abdomen moderately slender, cylindrical, with parallel sides, the basal 

 segments hardly thickened, segments 2-4 transversely carinated, dorsal and lateral 

 carina? very slightly marked, segment 8 not perfoliate in female : wings long, rather 

 pointed at the tips, pterostigma short or moderate ; fore wings with 8-12 antenodal 

 and 7-14 postnodal nervures, the last antenodal and the first two or three postnodal 

 nervures not continuous, and the following postnodals of the first and second spaces 



