304 ME. W. F. KIEBT — A EEVISION OF 



segment 8 not perfoliate in female : wings and pterostigma rather long ; fore wings 

 with 10-11 antenodal and 8-9 postnodal nervures, the last antenodal and the first 

 three postnodals not continuous, cells of the postnodal area simple, triangle moderate, 

 on a level with that of the hind wings, traversed or open, followed by two rows 

 of cells, afterwards increasing to three, nearly to the hind margin (the first row 

 beyond the triangle often consisting of three cells), no supratriangular nervures, one 

 cross nervure in the lower basal cell, subtriangular space consisting of three cells 

 (rarely two), sectors of the arculus stalked, slightly curved at the extremities, nodal 

 sector hardly waved in the middle and not much curved, subnodal sector very slightly 

 irregular beyond the middle, cells between the nodal and subnodal sectors only 

 bisected near the hind margin ; hind wings rather broader than the fore wings, with 

 6-8 antenodal and 7-9 postnodal nervures, the first two postnodals not continuous, 

 triangle free, its base on a level with the arculus, followed by three rows of cells, 

 increasing, no supratriangular nervures, one cross nervure in the lower basal cell, 

 sectors of the triangle widely separated at their origin : spines of the legs slender, 

 moderately long, stiff; claws of the tarsi notched before the tip: anal appendages of 

 the male as long as the eighth segment, or shorter, the lower one a little shorter than 

 the others; appendages of the second segment conspicuous, the hamulus short, 

 recurved. 



Type Libellula didyma, Selys. 



Genus 69. Erythemis. 

 (Neuration, Plate LV. fig. 3.) 

 Hagen, Neur. N. Amer. p. 168 (1860); Brauer, Verh. zool.-bot. Ges. Wien, xviii. pp. 368, 723 

 (1868). 

 Frontal tubercle distinctly bifid; eyes contiguous in the middle; abdomen rather 

 short and broad, triquetral, about as long as the hind wings, the basal segments 

 considerably expanded when viewed laterally, but not visibly from above, segments 

 2 and 3 carinated, segment 8 not perfoliate in female : wings rather short, pterostigma 

 moderate; fore wings with 12 antenodal and 9-11 postnodal nervures, the last ante- 

 nodal and the first two postnodals not continuous, cells of the 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, one cross nervure in the lower 

 basal cell, subtriangular space consisting of three cells, sectors of the arculus stalked, 

 regularly curved, nodal sector as in Mesothemis, the subnodal sector and upper sector 

 of the triangle a little broken for the last fourth of their length, the cells between 

 the nodal and subnodal sectors only bisected close to the hind margin ; hind wings 

 slightly broader than the fore wings, with 8-9 antenodal and 9-12 postnodal nervures, 

 the first two postnodals not continuous, triangle free, followed by three rows of cells, 

 no supratriangular nervures, one cross nervure in the lower basal cell, sectors of the 



