THE SUBFAMILY LIBELLULIN^E. 271 



Genus 11. Neurothemis. 

 (Plate LIV. fig. 2 ; neuration, Plate LV. fig. 2.) 

 Brauer, Verh. zool.-bot. Ges. Wien,, xvii. p. 8 (1867), xviii. pp. 366, 717 (1868). 



Frontal tubercle bifid or truncated; eyes connected by a short space in front; 

 abdomen moderately slender, generally shorter than the hind wings, the basal segments 

 not thickened, the longitudinal carina; slightly marked, the second and third segments 

 transversely carinated (fourth imperfectly) ; eighth segment not perfoliate in female : 

 wings long, rather pointed at the tips, pterostigma moderately long; fore wings with 

 from 12-30 antenodal and 7-20 postnodal nervures, the last antenodal sometimes 

 continuous, and the first two to four postnodals not continuous; cells of the lower 

 postcostal space simple at the extremity, though the costal spaces are occasionally more 

 or less divided between the base and the pterostigma ; triangle placed just beyond that 

 of the hind wings, variable in form, divided by one or more nervures, and often (where 

 the neuration is close) reticulated, followed by from 3-12 rows of cells ; 2-8 supra- 

 triangular nervures, three nervures at least in the lower basal cell, and often eight or 

 nine ; subtriangular space consisting of five cells and upwards, often ill defined, and 

 containing very numerous cells; nodal and subnodal sectors and lower sector of the 

 arculus continuous, but more or less waved, the cells between the two former often 

 bisected, sectors of the arculus stalked ; hind wings slightly or considerably broader 

 than the fore wings, with from 10-20 antenodal and 6-20 postnodal nervures, the first 

 two to four postnodals not continuous ; triangle traversed by one or more nervures, and 

 often reticulated, the sectors united at base ; 1-3 supratriangular nervures, lower basal 

 cell with from 1-3 nervures (generally 2): anal appendages rather short. 

 Type Libellula fulvia, Dru. 



Genus 12. Diastatops. 

 Rambur, Ins. Nevr. p. 135 (1842); Brauer.. Verh. zool.-bot. Ges. Wien, xviii. pp. 364, 715 (1868). 

 Frontal tubercle raised, slightly divided in the middle ; eyes distinctly separated, con- 

 tiguous at no point ; abdomen moderately slender, shorter than the hind wings, a little 

 thickened beyond the middle, but the basal segments not thickened, segments 2-4 

 transversely carinated, dorsal carina well marked, segment 8 not perfoliate in female : 

 wings rather short, rounded at the tips, pterostigma very long, neuration extremely 

 close ; fore wings with the costa deeply concave between the base and the nodus, with 

 14-22 antenodal and about 10 postnodal nervures, the last antenodal and the first two 

 or three postnodal nervures not continuous; the postnodal nervures of both spaces 

 frequently anastomosing between the nodus and the pterostigma, or the cells more 

 regularly bisected; triangle generally long and narrow, placed considerably beyond 

 that of the hind wings, crossed by four or more nervures, and often reticulated, 

 followed by 6-9 rows of cells; 4-6 supratriangular nervures, subtriangular space not 



