LIBELLULIN A, 
discoidal and internal triangles cross-veined, 
four or more post-triangular rows, postcostal cells 
increasing to two or more rows proximal to level 
of submedian cross-vein, two cross-veins below 
the stigma; area between principal sector, &c., as 
above for Tauriphila ; discoidal triangle of front 
wing as far distal to the level of the discoidal 
triangle of hind wing as the latter triangle is 
long; vulvar lamina of female more than half 
as long as segment 9, deeply bilobed . . . . TRAMEA. 
SS. Nodal sector strongly waved in its middle, hind 
wing with two submedian cross-veins, anterior 
lamina of male bilobed; abdominal segments 4 
and 3 each with two, 5 and 2 each with one 
additional transverse carina; front wing with 
discoidal and internal triangles cross-veined, three 
or more post-triangular rows ; discoidal triangle of 
front wing as far distal to the level of the discoidal 
triangle of the hind wing as the latter triangle is 
long ; vulvar lamina of female almost wanting . . Panrata. 
AA. Hind lobe of prothorax erect, as wide as or wider than the other lobes, 
its hind margin usually bilobed (except in Rhodopygia) ; no supra- 
triangular cross-veins, one submedian cross-vein (two in some Platyplaz), 
discoidal and internal triangles of front wing cross-veined (except in 
some forms of Perithemis). 
V. Cross-veins immediately below the stigma one or more, when only one 
placed at or proximal to the middle; last antenodal of front wing not 
continued to median vein (except in some Platyplaz). 
W. Bridge-cross-veins two or more (one subnodal, the others ante- or 
post-nodal), anterior side of discoidal triangle of front wing little, if 
any, shorter than the proximal side, sectors of arculus of front wing 
arising not from a common stalk or from a stalk not longer than 
the lower piece of arculus, abdominal segment 4 with an additional 
transverse carina. . . . 1. 1 ww we) OPERITHEMIB. 
WW. Bridge-cross-veins one (subnodal), anterior side of discoidal 
triangle of front wing markedly shorter than proximal side. 
X. Spines on the third tibia 11-21 in each row, slender ; sectors of 
triangle of hind wing arising from the same point (except in 
some Cannacria gravida). 
Y. Arculus at or distal to the second antenodal, hind lobe of 
prothorax not bilobed, sectors of arculus arising from a common 
stalk longer than lower piece of arculus, genital hamule of male 
two-branched. 2. . . 2. 1. 1 1 1 1 we ee )6«)6Reopopyera. 
YY. Arculus between the first and second antenodals, hind lobe of 
