236 PROCEEDINGS OF THE ACADEMY OF [May, 



15. Between Ms and M4 is (a) one cross-vein proximal to the level 

 of the subnodus and (6) at the wing-margin are two or three 

 rows of cells. 



17. Between M4 and Cui are (a) 2-3 antenodal cells and (b) at the 

 wing-margin one row of cells. 



19. Between Cui and Cu2 at the wing-margin is one row of cells. 



20. Area posterior to Cu2 less developed, having only one row of cells. 



21. Anal vein separating from the hind wing-margin at the mid-level 



of the quadrilateral, hence distad both to (a) the level of the 

 arculus and (6) that of the cubito-anal cross-vein. 



22. No anal cross-vein proximal to the level of the distal end of the 



quadrilateral, but there is a cross-vein continuing the vein 

 which forms the distal end of the quadrilateral to the wing- 

 margin; this cross- vein is absent in Phenacolestes, Thaumato- 

 neura and Paraphlebia. 



Note. — The wing figured by Prof. Needham (Genealogic Study, 

 PL 53, fig. 4) as that of "Philogenia sp.?" is not Philogenia, but 

 Megapodagrion Selys sens. kit. (AUopodagrion Foerster). 



Comparison of IMegapodagrion (nebulosum^^) with 

 Phenacolestes. 



{M. nebulosimi 2 cf, Bolivia.) 



These two forms agree in the characters above numbered 1, 3, 5, 

 7, 10, 11, 14, 16, 18, 21a, 22. 



These two forms differ in the characters given below; after each 

 number the diflference shown by the Megapodagrion is stated. 



2. Only two antenodals. 



4. Stigma having its proximal edge less oblique. 



6. The longitudinal veins show less curvature. 



8. Between Mia and M2 at the wing-margin are two rows of cells. 



9. M2 separates from Mi at .45 to .41 of the distance from nodus 



to stigma. 



12. Between Rs and Ms at the wing-margin is only one row of cells. 



13. Arculus at the second antenodal. 



15. Betw^een Ma and M* is (a) only one cross-vein proximal to the 

 level of the subnodus and (6) at the wing-margin are two rows 

 of cells. 



17. Between M4 and Cui are (a) 3-5 antenodal cells and (6) at the 

 wing-margin only one row of cells. 



19. Between Cui and Cu2 at the wing-margin is only one row of cells. 



20. Area posterior to Cu2 wath only one row of cells. 



21 Megapodagrion nebulosum Selys is referable to the recently proposed genus 

 AUopodagrion of Forster, Wien. Ent. Zeit., XXIX, p. 51, 1910. 



