THE SUBFAMILY LIBELLULINiE. 303 



tinuous, cells of the postnodal area simple, triangle rather long and narrow, traversed, 

 on a level with that of the hind wings, and followed by three rows of cells, no 

 supratriangular nervures, one cross nervure in the lower basal cell, subtriangular space 

 consisting of three cells, sectors of the arculus stalked, curved at the extremities, nodal 

 sector with the basal half more or less undulating, subnodal sector a little broken for 

 the last fourth of its length, where it closely approaches the nodal, several of the inter- 

 mediate cells generally bisected towards the hind margin ; hind wings broader than the 

 fore wings, with 10-11 antenodal and 12-15 postnodal nervures, the first two post- 

 nodals not continuous, triangle free, followed by three rows of cells, no supratriangular 

 nervures, one cross nervure in the lower basal cell, sectors of the triangle separated at 

 their origin : anal appendages of the male straight, parallel, not much longer than those 

 of the female ; legs long, rather stout, hind tibiae with two i-ows of about five or six spines. 

 Type Liiellula vesiculosa, Fabr. 



Genus 67. Mesothemis. 



(Neuration &c., Plate LVII. figs. 4, 4 a.) 



Hagen, Neur. N. Amer. p. 170 (1861) ; Brauer, Vnrh. zool.-bot. Ges. Wien, xviii. pp. 369, 721 

 (1868). 



Frontal tubercle slightly concave before; eyes contiguous; abdomen moderately 

 stout, hardly as long as the hind wings, segments 2 and 3 laterally thickened, carinated, 

 and segment 4 with a false carina, segment 5 the slenderest, the abdomen being 

 gradually thickened beyond, segment 8 not perfoliate in female, pterostigma long: fore 

 wings with 10-15 antenodal and 9-11 postnodal nervures, the last antenodal and the 

 first two postnodals not continuous, cells of the lower postnodal area simple, triangle 

 rather narrow, traversed, on a level with that of the hind wings, and followed by three 

 rows of cells, no supratriangular nervures, subtriangular space consisting of three cells, 

 sectors of the arculus stalked, curved at the extremities, lower basal cell with one cross 

 nervure, nodal sector undulating at the base, but hardly beyond the middle, which is 

 arched, the cells between the nodal and subnodal sectors generally bisected towards 

 the hind margin ; hind wings distinctly broader than the fore wings, with 6-9 antenodal 

 and 9-11 postnodal nervures, the first two postnodals not continuous, triangle open, 

 followed by three rows of cells, no supratriangular nervures, one cross nervure in the 

 lower basal cell, sectors of the triangle distinctly and often widely separated at base : 

 anal appendages of male rather short ; spines of legs very strong, especially those on 

 the hind tibite (two rows of five to seven) and at the extremity of the hind femora. 



Type Libellala simplicicollis. Say. 



Genus 68. Miceathykia, g. n. 

 Frontal tubercle concave or slightly bifid ; eyes contiguous ; abdomen slender, thick- 

 ened at the base and tip in both sexes, shorter than, or as long as the hind wings, 



