184 ENTOMOLOGICAL NEW.S. [June, '03 



suggestion must not be interpreted as implying that the 

 former was, or is, the ancestor of the latter, but merely that 

 these two may be survivals of a group of genera which made 

 such a transition. 



Diaphlebia and Epigomphus agiee in .the possession of the 

 following generic characters : All wings : two rows of posttri- 

 angular cells out to at least the level of separation of subnodal 

 and principal sectors, no supra-triangular cross-veins. Front 

 wings : short sector and the first sector of the triangle diverg- 

 ing, only one row of postcostal cells to beyond the level of the 

 triangle, not more than two rows between the second sector of 

 the triangle and the hind margin of the wing.* Hind wings : 

 no anal loop. Males without a median inferior distal carina on 

 the tibiae. 



The generic characters of Diaphlebia which are different from 

 those of Epigomphus are : All zcing-s : no basal subcostal cross- 

 vein, arculus usually at second autecubital, its sectors separated 

 throughout by an interval considerably greater than the thick- 

 ness of either sector, one submedian cross-vein (sensit Sefysii, 

 1896), proximal end-vein of pterostigma prolonged to the 

 principal sector but no thicker than the other cross-veins 

 between the median vein and the principal sector, first and 

 fifth or sixth antecubitals thicker than the others. Front wings: 

 proximal angle of discoidal triangle as far distally from the 

 arculus as the length of the proximal side of the internal tii- 

 angle, 9-10 marginal cells between the short sector and the 

 first sector of the triangle. Hind ivings : not more than two 

 rows of cells between the second sector of the triangle and the 

 hind margin, anal triangle in the males three-celled, not reach- 

 ing to the anal angle. Head (viewed from in front): inferior 

 angle of the triangle formed by the ocelli about 120; Abdo/ncn S : 

 eighth segment widest of all the apical half. Tibicc: no differ- 

 entiation in the spines. 



Diaphlebia nexans n. sp. (PL viii, figs. 5, 9, 12). 



<j\ Lips and face pale green marked with dark brown as follows : a 



* 7.7 per cent, of the 52 wings of Epigomphus examined had three rows 

 for a distance of 2, 3 or 4 cells. 



