10. 



11. 



BY R. .T. TILLYAKD. 229 



Robust forms with many antenodals. Quadrilateral of hindwing 

 much wider than that of forewing Subfamily Epiophlehiince . 



Slender forms with two (rarely three) antenodals. Quadrilaterals of 



both wings narrow, with sharply acute distal angle 



Subfamily Lestince. 



'Robust forms with many antenodals. Quadrilateral wide, irregular. 



(Extinct). Subfamily Helerophlebiince. 



Slender forms with two (rarely three) antenodals. Quadrilaterals of 



both wings narrow, with sharply acute distal angles ». 



Subfamily Synlestinae. 



Sectors of the arculus attached to R. Hence, quadrilateral very wide 



basally Subfamily ThorincE. 



Sectors of the arculus not attached to R 9. 



Nodus very close to wing-base, at about one-seventh of the total wing- 

 length. Numerous postnodals Subfamily Psetidostiginaiince. 



Nodus at from one-fourth to less than one-half of the total wing- 

 length 10. 



Sectors of arculus arising at or a little above njiddle of arculus. No 



upward arching of Mi-8. Pterostigma nornial 



Subfamily' EpaUagincv. 



Sectors of arculus arising below middle of arculus. Mi-s arched 



strongly up to re-fuse with R. Pterostigma false or absent 



Siibf am i ly Calopteryginos. 



TMain veins diverging distally; intercalated sectors present besides the 



I postnodal sector Subfamily M egapodagrionini^. 



i Main veins not diverging; no intercalated sectors except the post- 



V nodal 11. 



rCug reduced to a cross-vein Subfamily Protoneurirue. 



ICu, normal 12. 



'2 



f Quadrilateral regular Subfamily Plalyctumime. 



\2.\ Quadrilateral irregular, usually with distal angle sharply acute 



I Subfamily AgrionmcB. 



EXPLANATION OF PLATES XXXII. -XXXIV. 



Plate xxxii. (Photomicrographs). 



Diphlehia lestoides Selys. 



Fig. 1. — Penultimate larval instar. Middle portion of wing; ( x 60). 

 Fig.2. — Penultimate larval instar. Basal portion of wing; ( x 60). 

 Fig.3. — Antepenultimate larval instar. Whole wing; ( x25). 



