302 ME. W. F. KIEBY — A EEV1SION OP 



of the abdomen, segment 8 slightly perfoliate in female : wings moderately long and 

 broad, the hind wings a little broader than the fore wings, pterostigma moderate ; fore 

 wings with 12-16 antenodal and 7-11 postnodal nervures, first one to three postnodals 

 not continuous, cells of the postcostal area sometimes bisected at the extreme tip, triangle 

 moderate, traversed, on a level with that of the hind wings, followed by three rows of 

 cells, increasing, subtriangular space consisting of two to five cells (generally three), 

 sectors of the arculus shortly stalked, and strongly curved at the extremities, one (rarely 

 two) subtriangular nervure generally present before the base of the triangle, one cross 

 nervure in the lower basal cell, nodal sector undulating considerably in the middle and 

 moderately curved at the extremity, the subnodal much less waved, the intermediate 

 cells bisected towards the hind margin; hind wings with 10 antenodal and 10-11 

 postnodal nervures, the first three postnodals not continuous, triangle free or traversed, 

 followed by three rows of cells, its base corresponding with the arculus, a supratriangular 

 nervure very rarely present, one cross nervure in the lower basal cell, sectors of the 

 triangle united or separated at base : anal appendages about as long as the ninth 

 segment, the lower appendage a little shorter than the other, those of the second 

 segment more or less conspicuous ; tibial spines usually strong. 



Type Libellula ccendescens, Fabr. 



I have been compelled to give this genus a very wide extension, and even to include 

 in it the bulk of the Old- World species placed in Lepthemis by authors. The 

 conspicuous differences in the shape of the abdomen visible in the groups typified 

 by Libellula sabina, Dru., brac7iialis, Beau v., ccerulescens, Fabr., and brunnea, Fonsc, are 

 unaccompanied by any permanent characters of neuration, and are linked together to a 

 great extent by intermediate forms. The most distinct-looking section is that of 

 L. sabina, Dru., and its immediate allies, in which the abdomen is more suddenly 

 and considerably inflated, and the sectors of the triangle on the hind wings are more 

 widely separated than in the other sections of Orthetrum ; but these characters are 

 only comparative, and are hardly sufficiently well marked or isolated to entitle this 

 group to generic separation. 



Genus 66. Lepthemis. 

 (Neuration, Plate LVII. fig. 1.) 



Hagen, Neur. N. Amer. p. 160 (1861) ; Brauer, Verh. zool.-bot. Ges. Wien, xviii. pp. 368, 723 



(1868). 



Frontal tubercle concave above ; eyes contiguous in the middle ; abdomen long and 

 slender, generally longer than the hind wings, the basal segments gibbous above, and 

 distinctly inflated when viewed from above as well as from the side, segments 2 and 3 

 carinated, segment 4 usually a little contracted at the base, segment 8 not perfoliate 

 in female : wings and pterostigma rather long ; fore wings with 14-15 antenodal and 

 12-13 postnodal nervures, the last antenodal and the first two postnodals not con- 



