xrv] CLASSIFICATION 265 



Tribe 3. . Aeschnini (figs. 124, 172, also PL II, fig. A). 



Triangles much elongated, reticulated. Bs either unforked, or asymmetri- 

 cally forked near or under the level of pt. Bspl curved concavely to Bs, lying 

 three or more cell-rows below the lower branch of Rs at its middle. Mspl 

 similarly curved and arranged with respect to J/ 4 . 



Larva with superior appendage usually bifid at tip. 



This tribe includes three series : 



Series 1. Gynacantha-Series. Female with a projecting fork under 

 seg. 10; larva with lateral setae on mask. 



Series 2. Aeschna-Series. Female with dentigerous tubercle under 

 seg. 10. 



Series 3. ^4raw;-Series. Anal angle of hindwing in male rounded. 



Family 2. LIBELLULIDAE. 



Triangles of fore and hindwings very different, that of f orewing transversely 

 elongated and far removed from arculus, that of hindwing longitudinally 

 elongated and close to or under arculus. Subtriangle of forewing well-deve- 

 loped, often reticulated; that of hindwing often absent. Antenodals of 

 first and second series corresponding, none specially thickened ; one or more 

 distal ones may be incomplete. Anal loop present. Eyes united dorsally 

 for a long distance (exc. Diastatops). Labium with median lobe reduced to 

 a small triangular piece, completely overlapped and closed in by the large 

 lateral lobes, which have no movable hook. Vertex a vesicle or tubercle 

 With the ocelli grouped round it. Female with ovipositor usually reduced 

 to a pair of simple valvula vulvae or a single vulvar scale (secondarily enlarged 

 in Uracis and others). Body-pattern bicolorous or unicolorous. 



Larva with broad oval body, and short 7-jointed antennae. Mask spoon- 

 shaped, with wide lateral lobes meeting medially in a series of closely fitting 

 teeth ; mental and lateral setae present. Gizzard with four fields, bilaterally 

 symmetrical. Gills duplex, lamellate. 



Subfamily 1. Cordulimae. 



Triangle of forewing not excessively narrowed. Anal border of hindwing 

 angulated in male (exc. Hemicordulia). Anal loop very variable. Eyes 

 with a slight sinuous projection near middle of posterior edge. A tibial 

 keel present on forelegs in the male. Anal appendages of male strongly 

 differentiated in the different species, but genitalia of seg. 2 not strongly 

 differentiated. Auricles present in male (exc. Hemicordulia). Body-pattern 

 bicolorous, or metallic unicolorous. Abdomen long, corduliform or cylindrical. 

 Larva with deep or moderate dentition of lateral lobes. 



